Transistors, the building blocks of modern electronics, are typically made of silicon. Because it’s a semiconductor, this material can control the flow of electricity in a circuit. But silicon has fundamental physical limits that restrict how compact and energy-efficient a transistor can be.

MIT researchers have now replaced silicon with a magnetic semiconductor, creating a magnetic transistor that could enable smaller, faster, and more energy-efficient circuits. The material’s magnetism strongly influences its electronic behavior, leading to more efficient control of the flow of electricity. 

The team used a novel magnetic material and an optimization process that reduces the material’s defects, which boosts the transistor’s performance.

The material’s unique magnetic properties also allow for transistors with built-in memory, which would simplify circuit design and unlock new applications for high-performance electronics.

“People have known about magnets for thousands of years, but there are very limited ways to incorporate magnetism into electronics. We have shown a new way to efficiently utilize magnetism that opens up a lot of possibilities for future applications and research,” says Chung-Tao Chou, an MIT graduate student in the departments of Electrical Engineering and Computer Science (EECS) and Physics, and co-lead author of a paper on this advance.

Chou is joined on the paper by co-lead author Eugene Park, a graduate student in the Department of Materials Science and Engineering (DMSE); Julian Klein, a DMSE research scientist; Josep Ingla-Aynes, a postdoc in the MIT Plasma Science and Fusion Center; Jagadeesh S. Moodera, a senior research scientist in the Department of Physics; and senior authors Frances Ross, TDK Professor in DMSE; and Luqiao Liu, an associate professor in EECS, and a member of the Research Laboratory of Electronics; as well as others at the University of Chemistry and Technology in Prague. The paper appears today in Physical Review Letters.

Overcoming the limits

In an electronic device, silicon semiconductor transistors act like tiny light switches that turn a circuit on and off, or amplify weak signals in a communication system. They do this using a small input voltage.

But a fundamental physical limit of silicon semiconductors prevents a transistor from operating below a certain voltage, which hinders its energy efficiency.

To make more efficient electronics, researchers have spent decades working toward magnetic transistors that utilize electron spin to control the flow of electricity. Electron spin is a fundamental property that enables electrons to behave like tiny magnets.

So far, scientists have mostly been limited to using certain magnetic materials. These lack the favorable electronic properties of semiconductors, constraining device performance.

“In this work, we combine magnetism and semiconductor physics to realize useful spintronic devices,” Liu says.

The researchers replace the silicon in the surface layer of a transistor with chromium sulfur bromide, a two-dimensional material that acts as a magnetic semiconductor.

Due to the material’s structure, researchers can switch between two magnetic states very cleanly. This makes it ideal for use in a transistor that smoothly switches between “on” and “off.”

“One of the biggest challenges we faced was finding the right material. We tried many other materials that didn’t work,” Chou says.

They discovered that changing these magnetic states modifies the material’s electronic properties, enabling low-energy operation. And unlike many other 2D materials, chromium sulfur bromide remains stable in air.

To make a transistor, the researchers pattern electrodes onto a silicon substrate, then carefully align and transfer the 2D material on top. They use tape to pick up a tiny piece of material, only a few tens of nanometers thick, and place it onto the substrate.

“A lot of researchers will use solvents or glue to do the transfer, but transistors require a very clean surface. We eliminate all those risks by simplifying this step,” Chou says.

Leveraging magnetism

This lack of contamination enables their device to outperform existing magnetic transistors. Most others can only create a weak magnetic effect, changing the flow of current by a few percent or less. Their new transistor can switch or amplify the electric current by a factor of 10.

They use an external magnetic field to change the magnetic state of the material, switching the transistor using significantly less energy than would usually be required.

The material also allows them to control the magnetic states with electric current. This is important because engineers cannot apply magnetic fields to individual transistors in an electronic device. They need to control each one electrically.

The material’s magnetic properties could also enable transistors with built-in memory, simplifying the design of logic or memory circuits.

A typical memory device has a magnetic cell to store information and a transistor to read it out. Their method can combine both into one magnetic transistor.

“Now, not only are transistors turning on and off, they are also remembering information. And because we can switch the transistor with greater magnitude, the signal is much stronger so we can read out the information faster, and in a much more reliable way,” Liu says.

Building on this demonstration, the researchers plan to further study the use of electrical current to control the device. They are also working to make their method scalable so they can fabricate arrays of transistors.

This research was supported, in part, by the Semiconductor Research Corporation, the U.S. Defense Advanced Research Projects Agency (DARPA), the U.S. National Science Foundation (NSF), the U.S. Department of Energy, the U.S. Army Research Office, and the Czech Ministry of Education, Youth, and Sports. The work was partially carried out at the MIT.nano facilities.

Section 702 of the Foreign Intelligence Surveillance Act lets US intelligence agencies collect communications from foreigners abroad without a warrant, and routinely sweeps in Americans’ emails, messages, and calls in the process.

The authority for this program is set to expire Friday, June 12th, 2026, at midnight. As we wrote earlier this week, Congress has been kicking the ball down the road for months now—temporarily postponing the expiration of the mass surveillance authority Section 702 of FISA in hopes that some consensus on a longer reauthorization could be reached. 

EFF has said for decades, every time this program is up for renewal: Section 702 should require a warrant before the Federal Bureau of Investigation can look at digital communications collected from Americans. If not, we should let the whole thing expire. And this time, it has, at least for a little while. 

Ironically, we have Bill Pulte to thank for this (probably temporary) reprieve. Earlier this month, Trump on Tuesday named Pulte – currently director of the Federal Housing Finance Agency (FHFA) and chairman of Fannie Mae and Freddie Mac – to replace current DNI Tulsi Gabbard, who announced her resignation last month. As has been widely reported, Pulte lacks any intelligence, military, or congressional experience. Senate Democrats responded by refusing to move forward with their version of a bill to reauthorize Section 702. Similarly, the House refused to approve even a short-term renewal of the program. 

However, the potential for abuse of this program is not limited to one individual or one administration. And if Congress is this concerned about one particular individual having access to Americans’ most sensitive information, the responsible thing to do is to put more transparency, accountability, and oversight into the structure of this program. 

Members on both sides of the aisle understand this. As we have seen several times this year already, the appetite for reform is stronger than ever. We hope to continue to see strong bipartisan opposition in Congress to renewing Section 702 without a warrant requirement for backdoor searches. Until then, the authority for this program should remain expired. 

This fluid pump was inspired by the way squids propel themselves through the water.

As usual, you can also use this squid post to talk about the security stories in the news that I haven’t covered.

Blog moderation policy.

MIT leadership has in the strongest terms rejected antisemitism and taken thoughtful and steadfast action to prevent it, to promote student-wellbeing, to respond to complaints raised by community members, and to address policy violations. 

Examples of actions MIT has taken since 2023 to address concerns of antisemitism

• MIT President Sally Kornbluth and other senior leaders have sent multiple campus-wide letters and video messages condemning reports of antisemitism on campus. 
• Prior to October 7, MIT joined the Hillel Campus Climate Initiative, which helps universities build awareness of and take action against antisemitism. Learnings from that engagement continue to guide MIT’s campus response. 
• MIT increased security around campus, including at the Office of Religious, Spiritual, and Ethical Life building, which houses MIT Hillel.
• MIT participated in the Brandeis Leadership Symposium on Antisemitism in Higher Education.
• MIT created multiple opportunities for training, education, and dialogue, e.g.: 
  • American Jewish Committee training on antisemitism for Academic Council, which comprises the Institute’s senior leadership 
  • ADL training on antisemitism for MIT’s Bias Response Team 
  • Institute-level educational programming, including an event featuring Professor Pamela Nadell—director of the Jewish Studies Program at American University and a scholar of antisemitism in America
• The Institute updated, publicized, and enforced its policies on protests and demonstrations and posters/displays.
• MIT helped create and provided financial support for two years of weekly lunches focused on supporting MIT’s Jewish community.
• MIT provided support for the faculty-created MIT-Kalaniyot program, which brings Israel-based faculty and postdocs to MIT with the intent of building and strengthening ties between Israeli researchers and the MIT community.
• The Institute established a cross-functional team with representatives from the Institute Discrimination and Harassment Response Office (IDHR), Office of Student Conduct and Community Standards (OSCCS), Division of Student Life, Human Resources, and the Office of General Counsel to promptly and fairly triage reports of antisemitism and other forms of bias relating to the conflict in the Middle East. 
• Instituted disciplinary proceedings for policy violations stemming from campus protests and related activities, which resulted in significant sanctions for a number of students, including suspensions, expulsions, and numerous individual bans from being on campus, as well as permanent derecognition of a student organization. 
• And MIT established a Title VI coordinator.

Student discipline process improvements

Apart from individual student discipline cases as described above, MIT conducted a holistic review of its student discipline process, which resulted in a number of policy and procedure changes, including: 

• The senior administration has a more direct role in reviewing significant student discipline cases, with the Vice Chancellor for Student Life regularly conferring with the Chair of the Committee on Discipline (COD) and participating in hearing panels in serious cases. 
• The role of the Senior Associate Dean of Student Conduct and Community Standards has been enhanced and elevated, reporting directly to the Vice Chancellor for Student Life. 
• A more streamlined process allows the Chair of the COD to take action in response to noncompliance with previous COD sanctions.
• Additional sanctions were added to the COD Rules, giving the COD a broader range of tools to address student misconduct.
• Enhanced training on discriminatory harassment were made available to COD members. 

Over the last couple years, MIT has experienced a significant decline in the number of reports of student misconduct arising out of allegations of antisemitism or other forms of bias based on religion or ethnic/national origin. 

Courts have dismissed lawsuits claiming antisemitism at MIT

As a result of MIT’s actions, including specifically some of those described above, federal courts have dismissed claims of antisemitic harassment and discrimination asserted against MIT under Title VI. In doing so, the courts have acknowledged the escalating steps MIT has taken to promote a safe, inclusive community for its Jewish community members. For example, in a unanimous decision by the First Circuit Court of Appeals holding that MIT satisfied its Title VI obligations, the Court noted:   

• “As the protest gatherings occurred over the course of seven months, culminating in the Kresge Lawn encampment, MIT took an escalating series of actions aimed at calming the turmoil without violence… Even if we accept plaintiffs' position that some conduct of some protestors was antisemitic, that would not provide a Title VI pretext for requiring MIT to eliminate the protests entirely. In that respect, by managing the situation so as to avoid escalation and violence, MIT was much more effective than plaintiffs claim.” 
• “[A]ny reasonable school administrator in MIT's position could have reasonably surmised that its progressively evolving responses prevented the on-campus conflict from exploding into real violence between October 2023 and May 2024.”

Importantly, MIT took these steps to protect the MIT community even while the Court concluded that much of the campus protest activity at MIT amounted to legally protected expression and not a violation of Title VI: 

• “This absence of consensus reflects ongoing debate as to the relationship between anti-Zionism and antisemitism – debate that our constitutional scheme resolves through discourse, not judicial fiat. Indeed, the debate on occasion has been formal and high profile…We decline to interpret Title VI as arming either side of that debate with the powers of a censor.”

2026 Quality of Life survey results

Jewish student sentiment has significantly improved and is now higher than the general MIT student population. 

Below are data from the spring 2026 Quality of Life survey, a community-wide survey administered every two years to better understand the lives of faculty, staff, postdoctoral scholars, and students. The data reflect responses from those who selected “Judaism” as their religion, alone or in part (respondents were able to select more than one religion).

Overall, how satisfied are you being a student at MIT? 
(Percentages are a sum of respondents who selected “very satisfied” + “somewhat satisfied”)

Jewish Undergraduates:
2024: 87%
2026: 97% (compared to 86% for all undergraduate students) 

Jewish Graduate Students:
2024: 78%
2026: 94% (compared to 88% for all graduate students)

I feel that I belong at MIT. 
(Percentages are a sum of respondents who selected “strongly agree” or “somewhat agree”)

Jewish Undergraduates
2024: 83%
2026: 92% (compared to 80% for all undergraduate students)

Jewish Graduate Students 
2024: 70%
2026: 79% (compared to 79% for all graduate students)

Notably, not a single Jewish undergraduate respondent in 2026 disagreed with the statement “I feel that I belong at MIT.”

In winter 1997, at age 60, when many researchers might be looking forward to retirement, Harriet Latham Robinson SM ’61, PhD ’65 was pursuing a faculty position as the chief of microbiology and immunology at the Yerkes National Primate Research Center at Emory University in Atlanta, Georgia. 

She got the job. 

There, she would also co-found GeoVax, a biotechnology company, based on her preclinical research, including work on developing an HIV-1 vaccine. 

Often, as the only woman in a room throughout much of her career, and in the still-developing and male-dominated field of molecular biology, her colleagues were referred to as “doctor” or “professor” at scientific symposia and committee meetings. 

“In contrast,” she recalls, “I was Harriet.”

Becoming a scientist

Robinson was born in 1938, the second of four children, to a mother, Ruth, and a father, Allen, from Ohio and Connecticut, respectively. After finishing grammar school, she attended the Girls’ Latin School, a public magnet school for college-bound young women. Although the school offered only two classes in science — one semester of chemistry and a health class — Robinson credits her time there for inspiring a lifelong love of learning, especially history and languages. 

“At our 50th and 60th high school reunions, I was struck by what my Girls’ Latin school classmates had done with their lives,” she says. “We had become not only wives, mothers, teachers, and nurses we were supposed to become, but also physicians, lawyers, professors, politicians, and businesswomen.” 

Robinson pursued her undergraduate studies at Swarthmore College, where she intended to study political science. After an introductory biology course, however, she switched her major. Despite the shift, a love of languages persisted: Robinson took Russian and, the summer after her senior year of college, served as a Russian-English speaking guide at the 1959 American National Exhibition in Moscow. Despite mounting tensions between the United States and the Soviet Union, she served again in a similar role from September 1961 to January 1962 for a traveling transportation exhibition in Russia and Ukraine, where she was stationed by a Ford Thunderbird, wearing a TWA stewardess uniform.

“We were true entertainment, as well as education, and I worked to do my best to answer questions about America,” she says. “I was most surprised by the pride the Russian people took in the post-World War II accomplishments of their country.” 

Robinson might not have had a career in science at all had it not been for a dean at Radcliffe College who recognized Robinson’s interest in science. Robinson had thought it appropriate, as a young lady, to pursue marriage and to only further her education to become a teacher or nurse. Seeking permission to take chemistry instead of education courses to fulfill requirements for getting a teaching degree, she was referred to a dean who considered it perfectly appropriate for a young woman to pursue another career. Robinson recalls that the dean declared, “My dear, you want to be a scientist.” 

The foundation for a career

Robinson was soon accepted at MIT and was offered a fellowship to teach in an introductory biology lab to help pay her way. She returned from Moscow just five days before the start of a master’s program in biochemistry. In the Department of Biology at MIT, there were only a handful of women, no female faculty, and few ladies’ rooms in 1959. 

It was there that she met Walter “Wally” J.K. Tannenberg, a onetime partner but lifelong friend and companion, an MD taking courses at MIT. He wasn’t “at all taken aback by my becoming an educated woman,” Robinson says. He taught her to ski, and they sailed his lightening, the Ondine, in circles around Robinson’s parents’ comparatively slow motor sailor, the Palometa. 

Their breakup just before the winter holidays in 1963 precipitated her reentry to graduate school, to pursue her thesis work in the lab of Jim Darnell; she threw herself into studies to sit a qualifying exam less than a month after reentry. 

“A Bell Labs physicist who had just joined the Darnell Lab opined that any concept in biology could be mastered in two weeks,” Robinson says. “Much to everyone’s amazement, I not only passed my qualifying exam, but did much better than expected.”

It was at the University of California at Berkeley during her postdoctoral work that she met her husband. Although the marriage would not last the test of time, Robinson and her husband were blessed with three boys, each 13 months apart.

Robinson knew that she wanted to take time away from her career to stay home with her children before they entered primary school. As a graduate student at MIT, to prepare for both having a career and pursuing motherhood, Robinson hired a housekeeper and committed to being in the lab for only a typical 9 a.m. to 5 p.m. workday. If she were to compete with her male counterparts and be with her children, she needed to be able to get things done while working short hours. 

Robinson successfully completed her thesis work in just over two years.

“The difference between bearing children and rising up professional ladders is that you can start up the professional ladder after you are 40,” she advises. “Such is more problematic for having children.”

Robinson’s thesis work at MIT concerned how DNA, which is identical in all cells of an organism, produces different cell types from the same genetic blueprint. She explored this question through the lens of messenger RNA, a gene product that determines which DNA sequences are expressed in a cell. Later, her work on cancer-causing viruses in chickens would help lay the groundwork for gaining insight into genes that can cause tumors to form. 

“In contrast to becoming a wife, becoming a PhD from MIT did not falter, but rather provided me with the foundations for a career I loved in which I used molecular biology and chickens to study the genetic basis of cancer and pioneered the use of DNA as a new method of vaccination,” Robinson says.

Cancer-causing viruses

Robinson, supported by an National Science Foundation fellowship, pursued postdoc training at the University of California at Berkeley, in the lab of Harry Rubin. The Rubin Lab specialized in work on a virus known to cause cancer: the Rous sarcoma virus, which causes rapid tumor onset when introduced into chickens. RNA, it had recently been discovered, was the underlying genetic cause of tumors developing in chickens exposed to the Rous sarcoma virus. It cannot, however, do this deadly work without co-infection with something called a helper virus — in this case, avian leukosis virus. 

Both Rous sarcoma virus and its helper viruses were retroviruses, which can make DNA copies from RNA sequences, a departure from the previously accepted dogma that DNA is only transcribed into RNA, and not the other way around.

Robinson joined the Worcester Foundation for Biomedical Research in 1977, where she continued research on Rous helper viruses and had the opportunity to run her own lab for the first time. In 1998, she was recruited to be a professor of pathology at the University of Massachusetts Medical Center. While there, she conducted pioneering studies on the use of DNA for vaccination and worked on developing an AIDS vaccine. 

In 1999, she moved again, this time to step into the role of chief of microbiology and immunology at the Yerkes National Primate Research Center at Emory University, where she began testing her candidate HIV vaccines in primates. While at the University of Massachusetts and Emory, Robinson and her lab used DNA vaccines, both with and without a poxvirus booster vaccine provided by Bernie Moss at the National Institutes of Health, to immunize animals against influenza, HIV, measles, and Ebola.

“From the early days of DNA vaccines, I had wanted to start a company to help move DNA vaccines from bench to bedside,” she says. 

Thus, GeoVax, short for “Georgia Vaccines,” was born. Robinson co-founded it with Don Hildebrand in 2001 after her move to Yerkes; Robinson would serve as chief scientific officer and a member of the board of directors during her tenure at the company. 

GeoVax successfully moved Robinson’s candidate AIDS vaccine into human clinical trials. These trials were stopped due to the generally poor performance of HIV vaccines in clinical trials, compared to the outstanding therapeutic potential of more recently developed anti-HIV drugs. GeoVax, however, continues to work on vaccines for Mpox, Covid-19, and Ebola, and has expanded its scope to include a cancer treatment.  

A well-deserved retirement 

After rounds of good-natured roasting from colleagues at Emory University and GeoVax, Robinson retired and has been enjoying returning to Palo Alto, California, where her oldest son, Bill, and his wife now live. 

Ultimately, Robinson hopes that her story can encourage everyone, especially young women, not to let pursuing a challenging and enriching career prevent them from realizing the dream of having a family.

“I have had a wonderful life, far exceeding what I ever could have anticipated,” Robinson says. “I have had international adventure, the romance of a man who truly loved me, the joy of motherhood, and the warmth, wonder, and adventure of family and friends, and last, but not least, the exhilaration of a career in molecular biology.”

Let no one accuse Bernie Sanders of ducking the big questions. Writing in the New York Times last week, the senator asked: “Will the future of humanity be determined by a handful of billionaires who have promoted and developed AI, with virtually no democratic input, who stand to become even richer and more powerful than they are today?”

We agree entirely that this is one of the most potent questions facing global democracy today. Our book, Rewiring Democracy, surveys the emerging uses for and impacts of AI in democracy around the world and reaches the same conclusion: that the most urgent risk posed by AI is the ...

Scientists at a climate law conference said they will continue to study how corporate pollution leads to stronger heat waves, hurricanes and other disasters.

The order stopped short of requiring the agency to implement the program.

The Energy Department is giving millions to a company partially led by a far-right activist and telecom executive to build the nation’s first coal-fired power plant since 2013.

The California Air Resources Board is under pressure to stabilize the nascent market for carbon capture after the loss of federal grants, but critics say the proposed rules could incentivize risky projects.

Plaintiffs allege the company is misleading permitting authorities about its plans.

Countries can submit written comments until Friday.

In May, Amazon deforestation was 61.4 percent lower than in the same month in 2025, according to officials.

Floods that historically had a 1 percent chance of striking a coastline in a year are now about 12 times more likely, on average, according to a new study.

There are few treatment options available for people with disorders of the esophagus. Delivering drugs directly to this part of the body is difficult, so patients are usually treated with systemic drugs, which can have unwanted side effects.

To overcome that challenge, MIT engineers developed a gel-like oral drug formulation that can coat the mucosal lining of the esophagus after being swallowed, allowing drugs to pass through the tissue.

The formulation, which includes a hydrogel and other key ingredients that promote rapid drug absorption, could be used to deliver antibodies including infliximab, used to treat a number of autoimmune diseases, or other types of antibodies or small-molecule drugs.

“There are many people with esophageal disease, and if you look at drugs for these conditions, they’re very limited in their ability to target this part of the body and it’s very difficult to develop them. We hope this platform will make it easier to develop systems that can help patients suffering from these conditions,” says Giovanni Traverso, an associate professor of mechanical engineering at MIT, a gastroenterologist at Brigham and Women’s Hospital, and an associate member of the Broad Institute of MIT and Harvard.

Traverso is the senior author of the new study, which appears today in Nature Biomedical Engineering. Former MIT postdoc Christina Karavasili, now an assistant professor at Aristotle University of Thessaloniki in Greece, is the paper’s lead author.

Direct delivery

One of the most common disorders of the esophagus is eosinophilic esophagitis, a type of inflammation that is caused by food allergies and leads the esophagus to close up, making it impossible to swallow food. Crohn’s disease can also cause inflammation of the esophagus. 

These disorders are usually treated with systemic drugs, including infliximab, an antibody that neutralizes an inflammatory protein called tumor necrosis factor alpha (TNF-alpha). However, this drug is an immunosuppressant that can lead to a higher risk for infections and other health problems.

Delivering the drug directly to the esophageal tissue could reduce those side effects, but this is inherently challenging because drugs taken orally pass through the esophagus so quickly. Adding to the difficulty, the esophagus is lined by a layer of tissue called stratified squamous epithelium, which is very impermeable to drugs.

Injecting drugs into the esophageal tissue is another option, but that is uncomfortable for patients and inconvenient because it has to be done at a doctor’s office. There is also at least one anti-inflammatory steroid drug that is formulated as a thick mixture, allowing it to remain in the esophagus longer after being swallowed, but the drug still has some difficulty passing through the impermeable squamous layer.

In this study, the researchers set out to develop new drug formulations that would include molecules that could increase the permeability of those esophageal cells, allowing more of the drug to pass through. 

To identify molecules that would enhance permeability, the researchers designed a screening system that mimics the structure of the esophagus. This system contains esophageal tissue pressed between two vertical plates. Drug formulations can be poured into the top of the system, simulating oral ingestion. The researchers can then measure how much of the drug passes through the tissue and is collected by wells in one of the plates.

Using this system, the researchers were able to measure how different excipients — inactive ingredients that help enhance drug effects — affect the permeability of the esophageal tissue. First, they tested about 100 different compounds and identified several top candidates. Then, they tested pairs of these excipients and found that the most effective combination was a pair of bile salts called sodium chenodeoxycholate and sodium cholate.

These salts appear to work together to loosen up the cell-cell junctions that normally act as a barrier to drug molecule entry. The researchers added those bile salts to a polysaccharide-derived hydrogel, which has a viscous consistency that allows it to lightly coat the lining of the esophagus.

“The hydrogel helps the formulation remain on the esophageal surface for longer, while the bile salts help increase transport across the tissue,” Karavasili says. “Our data suggest that the bile salts temporarily loosen these cell–cell junctions, mainly by interacting with calcium ions that help maintain junction integrity. This creates a more permissive pathway between the cells, allowing larger molecules to move into the mucosal tissue more efficiently.”

Minimizing side effects

In tests in animals, the researchers showed that this formulation could be used to effectively deliver infliximab to the esophagus. They also found that the loosening of the cell-cell junctions was temporary, and the cells returned to normal within three days.

This kind of delivery could help to avoid the side effects that patients sometimes experience when infliximab is given systemically, the researchers say. 

“We were interested in delivering anti-TNFs as a model drug, but also to help people who suffer from conditions like Crohn’s disease to have options that could be delivered to the site,” Traverso says. “If we have the possibility of site-directed delivery, we may be able to mitigate systemic side effects from these immunosuppressing agents.”

The researchers are now working on further optimizing the formulation for potential testing in humans. One key goal is to ensure that the gel adheres for long enough to deliver the drugs, but not so long as to cause discomfort for patients. The researchers are also exploring the possibility of using this approach to deliver other types of drugs. 

“This is a platform to enable the development of drug-delivery systems for the esophagus, which hasn’t been possible before because the tools haven’t existed,” Traverso says.

The research was funded by the Karl van Tassel Career Development Professorship, the Department of Mechanical Engineering at MIT, the Division of Gastroenterology at Brigham and Women’s Hospital, and the U.S. Advanced Research Projects Agency for Health (ARPA-H), which notes that the views and conclusions contained in this article are those of the authors and should not be interpreted as representing the official policies of the United States government.

Debates about vaccines are a recurring feature of contemporary politics. It turns out they actually date back more than 200 years, since the development of the first smallpox vaccine. MIT Professor Thomas Levenson, one of the country’s leading science writers, explores this important history in a new book about the contours of anti-vaccination thought. Levenson identifies different types of arguments vaccination opponents have developed through history, to help shed light on our current debates. He spoke with MIT News about his new book, “A Pox on Fools: The True Believers, Grifters, and Cynics Who Convinced Us to Reject Vaccines,” published this week by Penguin Random House. 

Q: Your book is about the longer history of anti-vaccination arguments. How far back does this go, and what have those arguments been? 

A: Hesitation, skepticism, and outright opposition to vaccines is not a new thing. It didn’t just happen starting in the late 1990s. Opposition to vaccines dates back to the beginning of the vaccine era, around the early 19th century. The first kind of opposition to vaccines is this sense that it violates the moral or the natural order. If you believed that God has authority over all of us and is mindful of everything, intervening in the disease process could seem blasphemous. 

In the early 19th century, the first true vaccine, the smallpox vaccine, used material from a related disease, cowpox, that doesn’t cause human beings to fall ill but does provide immunity to smallpox. That shifted the initial focus on God’s plans to the notion that vaccination — sticking some cow-stuff into people — violated the natural order. That sort of uneasiness is easily co-opted by a broader philosophy that says: If you align yourself with nature, you don’t need to use vaccines. 

I want to emphasize that in the early history of the anti-vaccine movement, there were reasonable fears being expressed. That changes over time, because science advances and the mystery of vaccines falls away. Still, the current anti-vaccine movement includes an impulse we all have: We wish to be in control. I would never deny the value of exercise, sunlight, and sanitation, but they are not sufficient when you are faced with many pathogens, and that’s what the modern anti-vaccine movement obscures. We share this world with bacteria and viruses that do their thing no matter what we eat or how much we exercise. 

Q: One section of your book explores the argument that vaccines have been actively harmful. What is that historical trajectory like? 

A: The idea that vaccines are not just unnecessary but actively bad for you is certainly very contemporary, but it too goes back to the beginning of the vaccine era. The first true smallpox vaccine came into public use in 1798. Very soon afterward people started pointing to different harms. Most of them were spurious. They were just making things up or mistaking another infection that was already there. But there were some flaws in the early forms of vaccination. People thought it conferred life-long immunity, and that wasn’t always the case. Additionally, people mistook syphilis infections for cowpox infections and transmitted syphilis to healthy people. There were maybe 750 cases in Europe.

What is repeated over and over in the history of vaccination is that when problems became apparent, people found a way to address them. A problem with diphtheria antitoxin at the turn of the century led directly to the first U.S. regulatory body, the Division of Biological Controls. And when the first polio vaccine was released to the public in 1955, one of the five drug companies making it had shoddy production practices. Thousands got sick, a hundred died, and some were paralyzed. The flawed vaccine was identified after two weeks on sale and stopped cold, and that ended that particular problem. What came out of it was the development of an FDA vaccine division with teeth. 

This is an area where the rhetorical skill of the anti-vaccine movement is on display. Anything human beings do carries some risk. Anything you do medically. I had my hip replaced last year. That carries some risk, such as surgical site infections. Well, the risks of vaccines are incredibly small. The most common response is a sore arm the next day, and maybe feeling under the weather. There is extremely close control over manufacturing now. We have stories of great harm, but the various specific allegations of the last 30 or 35 years have proven to be incorrect. But there’s a power to an anecdote versus statistics. 

Q: This book raises an issue also explored in your last one, “So Very Small,” that the sheer success of vaccines has, paradoxically, created a situation in which people take their effects for granted and find it easier to argue against them. Can you explain this phenomenon?

A: The reason that occurs is because vaccines have worked so brilliantly well. At the turn of the century, life expectancy was much lower, 47 years in the U.S. Several top causes of death were infectious diseases, and child mortality was high. Now, life expectancy is around 80 years in every developed nation, and child mortality is a tiny fraction of 1 percent. By 1970, you had almost a complete set of vaccines against what used to be called childhood diseases. And those diseases, up until extremely recently, had essentially disappeared. And that’s amazing. 

In the 1950s, before the measles vaccine, for instance, everybody had an experience of what it meant to be at at the mercy of waves of infection. But by the 1970s, that was no longer the expected, ordinary, common experience of raising kids. So we’ve forgotten how unpleasant even an ordinary case of one of these diseases is that you recover from, much less the more severe problems and death. In 1952, there was the largest polio outbreak in U.S. history, and it was scary to let your kid go to the movies or a swimming pool. They could go to someone’s birthday party, come back, and two weeks later start feeling muscle aches and a fever, and two weeks after that were maybe paralyzed, or dead. Then in 1955 the Salk polio vaccine came out. We don’t live that way any more. 

And so, because infectious disease seems like a nonexistent threat, vaccines, even with a tiny potential of harm, are made to seem worse because we don’t realize what happens if we let our vaccine coverage lapse. Well, we’re starting to get a glimpse of it, because the measles rate in the U.S. is shooting up, and we see what happens when vaccine coverage wanes, and in particular, when we lose herd immunity. In every population, some people cannot be vaccinated: infants who are too young, some people who have had transplants and are on immunosuppressive drugs, or the elderly in whom sometimes immunity wanes. Some diseases are so infectious, and measles is famous for this, that about 95 percent of a population must be vaccinated or the disease spreads. If we’re not at that threshold, every newborn is at risk. 

We don’t know what it’s like to live with the genuine risk and fear of those diseases. If you were born in 1970, you’re 56 now, and you literally never lived in a world where these diseases were common. 

Q: One source of resistance to vaccines is not strictly medical, but political and philosophical at one level. This also has a lengthy history, it seems. 

A: Another major theme of the anti-vaccination movement is to argue the question: Who has the right to say that somebody else must put something in their body? Again, all this is not new: In the mid-19th century, in the United Kingdom, there was a requirement that children be vaccinated against smallpox, and these mandates brought immediate opposition as an infringement of liberty. 

In 1850 the country’s top doctor, John Simon, physician to the privy council in England, described the right that people claim against vaccination as the liberty of “omissional infanticide,” that you are killing kids by not protecting them. Where do I stand? This is a philosophical question. Does the state have the right to make me do something because it will make society as a whole safer? I think, “Yes.” We live in societies, we depend on each other for all kinds of things, we aren’t just atomized individuals. But I can understand those who say, “No.” I just think it’s wrong. But it’s an argument that’s winning in some places. What I realized as I worked on this book is that the argument against vaccination on philosophical grounds is a lonely view: I owe nothing to anyone, and nothing owes anything to me. I think it’s a fearful one, too.

Q: For the vaccine hesitant, for those questioning vaccines, what will they get out of this book? 

A: On social media you see some people calling vaccine-hesitant people stupid, but that’s not right. People are busy. We all have daily lives. Get the kids ready for school, pack their lunches, go to work, get home, fix dinner. All of us offload some decisions to people we trust as experts. I have a ton of sympathy and empathy both for people trying to think how to make it through an incredibly complicated world. They hear noise about how vaccines are problematic and there’s no easy way for them to get to the bottom of the issue. That’s an opening the anti-vaccine movement exploits.

I hope my book reaches people who are vaccine hesitant. It’s understandable that people might think that where there’s smoke, there’s fire. But when you get down to the bottom question: Do vaccines help human flourishing, do they support the ability of human beings to live healthy, fulfilled lives? Yes, they do. Unequivocally, they are the greatest lifesaving invention humankind has ever come up with.

Jinhua Zhao MCP ’04, SM ’04, PhD ’09 has been appointed head of the Department of Urban Studies and Planning (DUSP), effective July 1. Zhao is the Class of 1941 Professor of Cities and Transportation at MIT.

In making the announcement, dean of the MIT School of Architecture and Planning Hashim Sarkis noted that Zhao is a renowned transportation planner, educator, and scholar, and a world leader in imagining and shaping better futures for mobility.

“Jinhua is one of those rare scholars who moves seamlessly between cutting-edge research and real-world policy,” says Sarkis. “His work with governments and transportation agencies around the world is a model for what MIT’s impact can look like beyond our campus.” 

Zhao succeeds Professor Christopher Zegras, who has served as department head since 2020. Under his leadership, DUSP expanded opportunities for students to engage directly with communities and policymakers around the world and continued to strengthen its long-standing connection between research and practice. “I want to extend my gratitude to Chris Zegras for his excellent and level-headed leadership, especially in challenging times,” says Sarkis.

After earning advanced degrees at MIT, Zhao joined the DUSP faculty. He says he found the Institute’s lack of conventionality and its culture of sharing ideas across disciplines stimulating. 

“MIT is a small school in the best sense of the word,” says Zhao. “We have fewer boundaries than other universities — intellectually and physically. Our ‘infinite corridor’ literally connects us to so many disciplines.”  

Shaping mobility systems worldwide 

That connectivity has been key for Zhao’s research and programs he has founded at MIT. Respected as a global authority on mobility, his research has been put into practice across some of the world's most complex mobility challenges. He and his team have shaped policy for Transport for London, the Mass Transit Railway in Hong Kong, and Japan Railways. His research has positively impacted leading U.S. transit authorities including Boston’s MBTA, the Chicago Transit Authority, and Washington’s Metropolitan Area Transit Authority. He has guided strategic planning for mobility industry on the future of autonomous and digital mobility, and developed autonomous vehicle (AV) deployment strategy in Singapore and the Middle East.

“Every city I’ve worked with faces the same tension: The technology is moving faster than the institutions designed to govern it,” says Zhao. “My work has been about closing that gap.”

At MIT, Zhao founded the MIT Mobility Initiative, which engages mobility and transportation researchers across the Institute as well as leaders in these disciplines from around the world. Zhao hosts the weekly MIT Mobility Forum via Zoom, with each discussion open to the public. What began as a small internal list of participants has grown into a global platform, drawing more than 200 practitioners, policymakers, and researchers every week around the world. The sizeable interest in the subject doesn’t surprise Zhao.

“No single discipline owns transportation,” says Zhao. “AI and autonomous systems are reshaping urban living faster than most institutions can adapt. The question is no longer what we know. It is whether the people who need it most — municipal governments, transport agencies, federal ministries — can access it when they make decisions on transportation. This is why the forum exists.”

Zhao directs the JTL Urban Mobility Lab that unites behavioral science and transportation technology to shape travel behavior, design mobility systems, and improve transportation policies. He is also a lead principal investigator with Mens, Manus, and Machina, an MIT initiative at the intersection of artificial intelligence, the future of work, and human learning, developing the tools and strategies for how cities, institutions, and economies can be designed to ensure AI augments, rather than displaces, the people within them.

DUSP’s global agenda

“If you look at the global agenda, what are the issues people are facing?” asks Zhao. “An aging society; AI and its impact on jobs; the energy crisis; traffic congestion. These are just some of the problems people feel connected to because they are embodied in our cities and communities. I want DUSP to engage with the city leaders and share our research and insights.” 

As he prepares to step into his role as department head, Zhao says he would like the research generated within DUSP to more quickly reach those who need it most: the planners, officials, and engineers making decisions in cities right now. A transit authority grappling with AV integration; a city government rethinking aging infrastructure; a leading transport ministry navigating the policy implications of AI — these are the constituencies Zhao believes DUSP should be in active conversation with.

“We know a great deal about how cities grow, how people move, and how that will change. The question is whether the people responsible for making these changes — in city halls, transport agencies, federal ministries — can access what we know, when they need it.”

Last fall, MIT Campus Dining recruited a group of students to make short videos and share their experiences as student diners on Instagram. The MIT Dining Ambassadors program is an effort to get students talking about — and helping to improve — MIT’s food services and systems. 

One of the inaugural ambassadors, Michaela Brown, a biochemical engineering major from Kingston, Jamaica, sat down to discuss what she’s learning as an ambassador, how she has adapted to dining-hall life, the best things about her mom’s cooking, what it was like to experience American Thanksgiving for the first time, and more.

Q: How did you get involved in the Dining Ambassadors program? 

A: Last October, my friend got a job. So I was like, I need to get a job. When I read the description, I said, Wait, this involves food, and talking to people, and posting on Instagram? That’s literally what I do every day. And I wanted to do my part. 

The ambassadors program has clear goals: They want to encourage students to use the dining halls, and they want us to find genuine issues MIT can work on. I wanted to be a part of that. The food at MIT is OK, but everything can be better. And you can’t make things better in any circumstance without trying. Plus — getting paid to eat food and talk? That is good money.

Q: What did you eat growing up? 

A: I love Jamaican food. On Sunday, we do a big dinner. (Well, my mom would do a big dinner; sometimes I would wash the vegetables.) She would cook rice, peas, and vegetables with a sauce, and either fried chicken with sauce or stewed chicken. We would eat that food on Sunday, and then maybe Monday, too. We call it “Sunday-Monday” in Jamaica. 

During the week, we eat flour dumplings, boiled green bananas, and lots of plantains. Sometimes, when my mom is on a health kick, she will boil everything, but plantains are so much better when you fry them! Often, she will serve that with ackee. That’s our national food. And she will cook saltfish or mackerel mixed with coconut milk. She also makes things like corned beef or tuna. On Fridays, we usually go out. 

For special occasions, sometimes we do pork or oxtail. Or sometimes we have escovitch fish; I think you fry it and you steam it. And then we have sides like dumpling, or banana, or bami, which is fried flour. And usually we eat these with okra and pickled onions, and add a little spice with Scotch bonnet pepper. 

And curry chicken! If I am home and I smell the curry, I get so happy. I genuinely feel better about myself. If you’re buying food from a vendor, like fried chicken and rice, you would ask for curry gravy because it is very essential in Jamaican culture. 

Q: What was your first project for the ambassadors program?

A: I did a video about Thanksgiving. I was excited, because it would be my first American Thanksgiving. As a kid in Jamaica, I saw it on TV. I watched Nickelodeon. Also, we learned about it in school. But we didn’t do Thanksgiving in Jamaica. So I was excited.

In the video, I was trying to cater to students who don’t normally celebrate Thanksgiving and show them the experience from a fresh perspective. I brought my friends with me and we all ate together. And luckily everyone thought the food was good. I really wanted to show the food — the mashed potatoes, the turkey, the jelly, the ham, all those things — because I think New Vassar did it really well. I wanted to show that. 

There are a lot of international students at MIT. I didn’t know what MIT was like until I got here. I wanted to show that I came here and liked it. Even while I was missing home, I was being introduced to other cultures — like the one in America — and MIT was helping me appreciate it through food.

Also, I wanted to show the community — being with my friends, giving thanks for the people around me. I really enjoyed that, and I thought it went well. My mom loved it.

Q: What have you done since then? 

A: Usually, I just try to take pictures when I’m in a dining hall and post them on Instagram. You know — regular life.

The other major thing was the global Olympics. Each day over two weeks, they had a special theme at each of the dining halls — Latin American at New Vassar, East Asian at Simmons, African at McCormick, European at Next House, Indian at Massey, and North American and Caribbean at Baker. 

My favorite was Baker, because, well, I’m a little biased. And also, I love the burgers at Baker. 
I told my friends they had to come. A lot of the cooking staff in Baker are Haitian. They would know how food from Haiti and Jamaica should taste. I knew they wouldn’t mess it up. 

I interviewed a lot of students, including two Haitians and one of my Jamaican friends. I asked about the food, about how it compared to regular dining hall meals. They were really positive. I think they liked the change. 

Q: Do you like to cook? 

A: Not really. The summer before I came here, I was like, OK, I’m gonna learn something. 
And then I proceeded to spend the summer out with my friends, and volunteering. So I wasn’t really in the kitchen. My mom would call me to come help her, and when I stepped in the kitchen it was so hot! I was like, I can’t do this, and I went back to my room. 

So I’m not really a cook, even though I live in Burton-Connor. It’s a cook-for-yourself dorm, so it doesn’t have a dining hall. A few weeks ago, I tried to do burritos. I got the beef and the seasoning. It was actually really good! I’m looking forward to it again. It’s just really hard to find the time. 


Q: When you’re posting, who do you imagine is looking at it? 

A: My friends. And my mom. Honestly, I just try to make sure you can understand what I’m saying because sometimes my Jamaican patois comes out, and I talk too fast. I also think about how the people I’m interviewing want to be seen, because this is not their job. They don’t have to be on camera, or help me. I try to make the experience as fun as possible for them. 

Q: What have you learned doing this work?

A: Walking up to strangers and getting their permission to record them is really new to me. I have learned so much about people. The other day, I was looking at a job application and it asked: Are you comfortable talking to other people and being social? This job has prepared me for all that so well. 

It also prepared me for dealing with people who might not be open to talking. I have learned to be OK with that, just walking away and handling it well. This is a skill set that I have now, and I look forward to working more and doing more interviews. I feel like, you know, a YouTuber!

Q: What dining stories do you want to tell next? 

A: I’m not sure. Dining is different for different people. For me personally, sometimes eating is a time to get together with other people. But sometimes I go to the dining hall by myself. It’s very much a time for me to decompress. Sometimes I don’t even want anyone to sit with me. I’m just trying to be with myself, watch my show, or do the learning sequence I have due at 11 o’clock. Or I just watch my TikToks. 

Maybe I’ll do a day-in-my-life dining story next, and go for breakfast at a dining hall. I would have to wake up earlier, but I would do it. 

Corporations harvest and monetize ever-growing amounts of our personal data, such as our browsing history and physical location. One bitter fruit of this poisonous tree is known as “surveillance pricing”: corporations offer the same product to two different people at two different prices, based on scrutiny of these people’s respective personal data.

Surveillance pricing is bad for privacy, equity, and price transparency. So EFF supports a California bill, S.B. 2564, which would ban this creepy practice.

How Surveillance Pricing Works

In 2025, the Federal Trade Commission (FTC) published a report about the practices of six companies that provide surveillance pricing services to hundreds of other companies, including grocery stores and apparel retailers. The report found that surveillance pricing draws upon customers’ browsing history, physical location, and shopping transaction history. Customers’ data can come from the vendor itself, from its surveillance pricing service provider, or from third-party data brokers. Customers are sorted into groups based on their personal data, as is done for targeted ads. As a result of surveillance pricing, a business might offer two customers different prices for the same product, based for example on whether they are a new parent, or whether they live near a business’s competitor.

As former FTC Chair Lina Khan explained:

Initial staff findings show that retailers frequently use people’s personal information to set targeted, tailored prices for goods and services – from a person’s location and demographics, down to their mouse movements on a webpage.

Unfortunately, the current FTC chair closed the FTC’s portal for public comments regarding surveillance pricing. Fortunately, the California Attorney General has initiated its own investigation of this practice.

Researchers have identified many examples of surveillance pricing:

• The Princeton Review offered people who lived in some zip codes a higher price for test prep services, compared to people in other zip codes. As a result, Asians were twice as likely as non-Asians to be offered a higher price.
• In a year-long study of tens of millions of rides in Chicago, Uber and Lyft offered a higher price for trips that ended in neighborhoods with high non-white populations.
• Tindr offered older people (aged 30 to 49) higher prices for Tindr Plus, compared to younger people (aged 18-29).
• Orbitz offered people who used Apple computers a higher price for hotel rooms, compared to people who used other types of computers.
• Hotel booking sites offered people from San Francisco a higher price for hotel rooms, compared to people from other cities.
• Target offered a higher price to people physically located at the store, compared to people located elsewhere.
• Staples offered a higher price to customers who lived further from the company’s competitors, compared to customers who lived closer.

Why EFF Hates Surveillance Pricing

This practice is harmful in many ways. First, surveillance pricing invades our privacy.  Vendors offer us a price only after scrutinizing our personal data about what we’ve clicked online and where we’ve travelled offline. Moreover, surveillance pricing incentivizes all businesses to harvest as much of our personal data as possible. Some businesses will use it for their own surveillance pricing. Other businesses, which might not themselves use it this way, will sell it to data brokers, which in turn will sell it to others for use in surveillance pricing.

Second, surveillance pricing can disparately burden people of color and other vulnerable groups. For example, as described above, surveillance pricing led to Asian people paying more for test prep services, older people paying more for dating services, and people living in non-white neighborhoods paying more for a ride home.

Third, surveillance pricing is opaque. Many people don’t even know when they’ve been subjected to it. Those that do often cannot determine the unknown reasons for the price they’re offered. As a result, consumer advocates will be less able to publish meaningful price comparisons to help consumers make choices. And regulators will be less able to identify unlawful pricing practices.

Thus, EFF and many other groups object to surveillance pricing.

Its defenders sometimes argue that surveillance pricing benefits consumers because it can lead to lower prices. But while some consumers some of the time might get lower prices because of surveillance of their personal data, other consumers will get higher prices, as shown by the examples above. Some recent studies indicate there will be losers and winners based on factors like whether a consumer is willing or able to switch products. Who loses or wins also will turn on the accuracy of the underlying data – yet surveillance pricing is often based on false information.

In any event, both losers and winners of this price discrimination are harmed by surveillance. Privacy is a human right, not a property to be bought and sold on a market. For this reason, EFF has long opposed pay-for-privacy schemes, in which a company charges a higher price to a customer who refuses to submit to processing of their personal data. Thus, even if surveillance pricing sometimes leads to lower prices (and again, it often will not), we oppose it as just another way that corporations try to make customers pay for their privacy.

What the California Bill Would Do

The key term of California’s S.B. 2564 is short and sweet: “a retailer shall not engage in surveillance pricing.”

The banned practice is defined as: “[i] a customized price for a good for a specific consumer or group of consumers, [ii] based, in whole or in part, on personally identifiable information collected through electronic surveillance,” including if that information is “acquired from a third party.” In other words, “surveillance pricing” is a customized price based on personal information.

The bill has two enforcement methods. First, state and local government may bring enforcement actions, and seek all manner of remedies including monetary penalties. Second, individual consumers may bring their own enforcements lawsuits, and seek the remedies of an injunction and attorney fees. We are pleased the bill provides this private right of action, which is the most important method of enforcement (we’d be even more pleased if the private remedies included liquidated damages).

The bill has three exemptions where surveillance pricing is allowed:

• First, for price differences “based solely on costs associated with providing the good to different consumers.”
• Second, for a discount offered to a consumer who is taking steps to terminate a service.
• Third, for a discount, conspicuously posted on a retailer’s website, that is uniformly available based on (1) criteria anyone can meet, such as signing up for a mailing list, (2) membership in a broadly defined group, such as seniors, or (3) participation in a loyalty program.

The bill’s author is California Assembly Member Chris Ward. Its co-sponsors are Consumer Reports and TechEquity. Its supporters include Consumer Federation, EPIC, Kapor Center Advocacy, Oakland Privacy, Privacy Rights Clearinghouse, labor unions, and other groups. The bill has advanced through the California Assembly and has arrived for consideration in the California Senate.

Why EFF Supports the California Bill

Surveillance pricing is just one part of a much larger problem: corporations maximizing their profits by invading our privacy. The all-too-common business model is to systematically harvest, collate, and store as much of our personal data as possible, and then monetize it through use and sale.

EFF’s general approach to this problem is a strong regulatory framework that we call “privacy first.” For example, laws should require businesses to “minimize” their data processing, meaning they must not collect, store, use, or disclose our data unless doing so is strictly necessary to give us what we asked for. Likewise, laws should require businesses to get our voluntary and informed opt-in consent before processing our data, buttressed by legal bans on coercive pay-for-privacy schemes and manipulative “dark patterns.”

A.B. 2564 is just a specific application of the minimization rule. Nobody who uses a web browser or a mobile app expects that, as a result, their clicks and footsteps will be funneled into personal dossiers, and later used by downstream businesses to offer a higher or lower price.

A.B. 2564 is also a specific application of the “no pay-for-privacy” rule. At its best, surveillance pricing is a corporate offer of a lower price in exchange for a consumer’s submission to surveillance of their personal data. This scheme encourages all people to surrender their privacy in exchange for a lower price. This is especially coercive for people with lower incomes, and thus carries the risk of creating a society of privacy “haves” and “have nots.” And swept into this supposed “bargain” is the potential for higher surveillance-based prices based on false information or erroneous inferences.

Surveillance pricing is very similar to online behavioral advertising, a business practice that EFF urges governments to ban. Both practices incentivize all businesses to collect as much of our personal data as possible, in order to later monetize it. Both practices lead some businesses to collate and store our data into dossiers about us for later use. Both practices use these surveillance-based dossiers to manipulate and limit our economic choices, by altering the advertisements and prices we see online. In the words of the FTC report discussed above: “Existing and common techniques used for targeted advertising can also be used for other forms of targeting prices.”

Absent a specific ban on surveillance pricing, as in A.B. 2564, it would be very difficult to protect the public from the many harms it causes. Corporate price-setting is increasingly opaque, making it difficult for consumers and regulators to determine whether a particular company set a particular price for a particular consumer based on their data, and if so, the particular data that it used. As a result, it would be very difficult in this context to enforce general laws requiring minimization or consent. Moreover, many such laws exempt how a business processes the data it directly collected from its own customers; for example, the California Consumer Privacy Act’s limits on “cross-context behavioral advertising” do not apply to how a business uses personal data it collected on its own website. Yet many practitioners of surveillance pricing (like Tindr) rely on such data.

Finally, there is little to no risk that A.B. 2564 will have unintended consequences that hurt internet users’ speech or technological innovation. The bill does not address any particular type of technology. It does not limit any collection, retention, or disclosure of personal data. It limits only one very narrow and easily defined use of data: use to set a customized price. And it has three broad exemptions.

In sum, EFF is proud to join with other groups in support of California’s A.B. 2564. You can read our support letter here.

In his 1927 paper, “A law of comparative judgment,” the American psychologist L. L. Thurstone proposed that when people select one option among multiple alternatives, they are picking the one that has the highest value to them, even though they cannot assign a particular number to that choice. 

Thurstone was a pioneer of “psychometrics” — a field built upon the premise that mental processes, which we cannot see, can nevertheless be measured and quantified. His 1927 paper laid the groundwork for what are now called random utility models, which provide a mathematical framework for describing human preferences — information that can be relied upon, in turn, to make predictions about various hypothetical situations.

Random utility models (RUMs) are so named because they assess the “utility,” or benefit, that can be obtained from a given choice — such as deciding which book to read first among the stack of novels you brought back from the library. “These models are inherently random,” explains Gabriele Farina, an assistant professor in MIT’s Department of Electrical Engineering and Computer Science (EECS) and principal investigator at the Laboratory for Information and Decision Systems (LIDS), “because people are different. Everyone has their own preferences, and even those preferences can vary from time to time.” For example, someone who normally picks coffee over tea in the morning, and prefers tea after dinner, may, upon occasion, mix up that order entirely.

RUMs, to be sure, are frequently used within government and industry in situations of far greater consequence than the selection of a hot (or iced) beverage. The models routinely facilitate predictions regarding what people will elect to do in so-called counterfactual (“what-if”) scenarios such as: How will they get to work or school if a major thoroughfare is shut down for construction? What routes and modes of transport will they take? Or, if a city suddenly receives a windfall of $20 million, how should those funds be disbursed to maximize the common good?

Given that RUMs have been with us for almost 100 years, growing in sophistication over time, one might imagine that, at this stage, there would be little room for improvement. That, however, is not the case. 

A paper presented in April at the International Conference on Learning Representations in Rio de Janeiro, Brazil, uncovered basic facts that show there is much more to be gleaned from these models than had traditionally been supposed. The paper was authored by Yeshwanth Cherapanamjeri, a former MIT postdoc now based at Nanyang Technological University in Singapore; Farina, also core faculty in MIT’s Operations Research Center (ORC); Constantinos Daskalakis, the Avanessians Professor of Computer Science at MIT and a member of MIT's Computer Science and Artificial Intelligence Laboratory; and Sobhan Mohammadpour, an MIT PhD student in computer science based at LIDS and EECS.

The group’s findings stem, in part, from a deficiency in the way RUMs are commonly estimated in practice, which has persisted since the days of Thurstone. The data upon which the models are estimated have been largely drawn from so-called pairwise-comparisons: In a choice between items A and B — whether it pertains to movies on Netflix, competing products on Amazon.com, news stories posted on Google, and so forth — which one would you pick? One reason this approach has been so pervasive, explains Daskalakis, is that “assigning a precise numerical score, such as 4.37, to the benefit you get from a single item is very hard. Whereas comparing two things, and deciding which one you like better, is cognitively much easier to do.” But therein lies the rub, he adds. “With this way of assessing people’s preferences, looking at just two things at a time, it is impossible to find correlations between the numerous choices.”

The standard way of applying RUMs assumes that the utilities derived from A and B are independent, but they may, in fact, be linked, and that would be important to know. If someone campaigning for elective office finds out that a potential voter favors gun control, for instance, there is a reasonable chance that same person also favors government-sponsored child care. Similarly, a fan of independent movies might also be partial to foreign films, but less enthusiastic about Hollywood action blockbusters. “If a digital platform has a blind eye to the existence of such correlations, it will not be able to estimate preferences very accurately,” Daskalakis notes. “And if Netflix regularly shows you an assortment of movies you don’t care about, you might sign off and cancel your subscription.”

The MIT team proved that it is impossible to get information about correlations from two-way comparisons alone. Correlations can be discerned, however, when large numbers of people rate three alternatives in their order of preference. The same information can also be obtained from a combination of best-of-three and best-of-two choices. In practice, Mohammadpour explains, “you would get a bunch of people to rank three items. You could then utilize the method we developed for merging those individual results into one big model that can provide us with the big picture.”

Their research effort, according to Farina, is focused on the computational side of RUMs, devising algorithms that can extract preference information and figuring out how much data is needed to do so or, equivalently, how many experiments need to be run. The good news, he says, is that efficient algorithms are, indeed, possible for this purpose. The requisite number of experiments does not grow exponentially with the number of items in the catalog or database that’s under review.

“This paper provides a crucial breakthrough,” comments Emma Frejinger, a computer scientist at the University of Montreal. “It mathematically proves why traditional data collection fails and demonstrates that simply asking users for their best-of-three [choices] unlocks the ability to accurately train these powerful models. This finding provides a highly practical roadmap for collecting better data to drive more accurate optimizations.”

“Building utility models is going to remain a very active area,” Daskalakis insists. “Just as RUMs have been critical to the internet economy since the late 1990s, they are, and will remain to be, critical to the alignment of AI models going forward.” More importantly, he adds, “RUMs play a central role in the commercial viability and usefulness of large language models [LLMs].” During the training period, people are typically asked to rank the various candidate outputs of these LLMs, from which the models can gain a better sense as to the kind of text — in terms of tone, style, and content — that is preferred. 

Given that we’re constantly “besieged with a vast sea of options in so many different domains,” Daskalakis says, “you cannot possibly ask people to communicate all their personal preferences for all possible scenarios. So what you can do instead is build a model that predicts what people think about the different possible outcomes. And you have to keep improving and updating your model in an iterative process until, hopefully, you can make good predictions.”