Highlighted Publications




 

Richards and Whaley (2026) examined how recent waves of health care consolidation have affected competition, prices, quality, and patient access in the United States. They asked whether mergers, vertical integration, private equity ownership, and insurer acquisitions have improved health care efficiency or primarily increased market power. The article synthesizes evidence from national hospital, physician, insurer, and private equity data, along with findings from numerous em

Leonard and Lipton (2026) examine whether California’s 2020 expansion of full-scope Medi-Cal increased health insurance coverage among noncitizens ages 19 to 25, regardless of immigration status. They analyze 2016–2022 American Community Survey data and compare young California noncitizens with older noncitizens in California and similar age groups in six other states. Using a triple-difference design, they find that the expansion increased Medicaid coverage by 4.2 percentage

Cheng et al. (2026) ask how common social sycophancy is in leading AI systems and how it affects users’ judgments, prosocial intentions, trust, and future use. They analyzed 11 large language models across 11,587 advice, interpersonal-conflict, and harmful-action prompts, then conducted three preregistered experiments with 2,405 U.S. participants. They found that AI affirmed users’ actions 49% more often than humans. Sycophantic responses increased participants’ belief that t

Layton et al. (2026) examine whether competition among private Medicare Advantage plans can successfully replace competition from traditional Medicare in delivering higher-value coverage. They analyze national Medicare enrollment, switching, mortality, payment, and market concentration data from 2007–2022, supplemented by prior empirical research. They find that Medicare Advantage enrollment increased from about 20% to more than 50% of beneficiaries, while four national insur

Abrams and Goonetilleke (2026) examined how stop-and-frisk practices vary across major U.S. cities and whether crime, poverty, demographics, or police resources explain those differences. They analyzed more than eight million pedestrian and vehicle stops recorded in 16 cities from 2019 through 2023. They found that stop and frisk rates differed by nearly two orders of magnitude across cities. Contraband discovery rates also varied substantially, ranging from 18% to 74% for pe

Dillon et al. (2026) examined whether providing knowledge workers with an integrated generative AI tool changed how they spent their time and completed their work. They analyzed telemetry data from a randomized field experiment involving 7,137 employees across 66 large firms who were assigned either access to Microsoft 365 Copilot or a control group over six months. They found that workers who regularly used Copilot spent about two fewer hours per week on email (a 17% reducti

Carrell et al. (2026) examined whether a simple information nudge encouraging recent high school graduates to enroll in summer community college courses increases summer enrollment. They analyzed data from a randomized field experiment involving 8,222 California high school seniors who had applied for financial aid and planned to attend college, linking survey responses with administrative college enrollment records. They found that students who received the informational mes

Monte, Porcher, and Rossi-Hansberg (2025) asked whether the COVID-19 pandemic permanently changed city structure by shifting workers toward remote work and whether those changes differed across cities. They analyzed a dynamic urban economic model together with U.S. cell phone mobility data from SafeGraph, housing price data from Zillow, Census and American Community Survey data, and National Longitudinal Survey of Youth data. They found that many large cities stabilized at ab

Kauer, McGuire, Schillo, and van Kleef (2026) asked how regulated health insurance competition differs between Germany, the Netherlands, Switzerland, and the United States. They examined insurance rules, market structures, coverage and spending statistics, and findings from studies. They found that European systems require broad participation, rely less on profit-driven insurers, and use collective regulation to control prices. The U.S. Marketplace is voluntary, covers only p

Agan et al. (2026) examined whether electing a reform-minded prosecutor changes misdemeanor and felony charging and conviction rates. They analyzed county-level administrative criminal justice data from the Criminal Justice Administrative Records System (CJARS) covering 25 jurisdictions, using variation in the timing of reform prosecutors taking office and a staggered difference-in-differences design. They found that reform prosecutors reduced misdemeanor convictions by about

Finkelstein and Gentzkow (2026) asked whether places that increase Medicare spending also increase life expectancy for older adults. They analyzed Medicare claims and mortality data for millions of beneficiaries, using migration (“mover”) designs to separate the effects of places from the characteristics of the people who live there. They found that places with larger causal effects on health care spending did not produce longer life expectancy. Place-based factors explained

Gottlieb and Nicholson (2026) asked how barriers to physician entry and competition from substitute health care providers shape physician markets. They reviewed evidence from medical school and residency data, physician workforce statistics, licensing regulations, insurance claims, earnings data, and prior economic research. They found that strict limits on medical school and residency positions continue to restrict physician supply, while nurse practitioners, physician assis

Bhattacharya, Illanes, and Stillerman (2026) ask how mergers affect consumer prices and whether U.S. antitrust enforcement effectively identifies harmful mergers. They examine 129 consumer product markets involved in 47 mergers from 2006 to 2017, using NielsenIQ retail scanner data. They find that mergers increased prices by only 0.4% on average, but effects varied substantially. Twenty-five percent of mergers raised prices by more than 3.9%, while another quarter reduced pri

Ainsworth, Liu, and Penner (2026) asked whether adopting a four-day school week changes teacher turnover in the short and long term. They analyzed administrative records for all public school employees in Oregon from 2006–2007 through 2023–2024, using a difference-in-differences research design to estimate the policy’s causal effects. They found that schools adopting a four-day week experienced a 2.0 percentage point increase in teacher turnover. This included a 0.7 percentag

Buehler et al. (2026) asked how physician incomes compare across the United States, Canada, the Netherlands, and Sweden, and whether higher US physician pay reflects physicians’ relative position in the income distribution or higher incomes at comparable income levels. They analyzed administrative tax records covering nearly all physicians in each country. They found that physicians ranked among the highest earners everywhere, but US physicians earned much more. Eighty-four p

Agniel et al. (2026) asked whether Medicare’s 2020 decision to cover methadone treatment for opioid use disorder changed how opioid treatment programs operated and whether it expanded access to care. They analyzed national administrative data on treatment facilities (2015–2023) and treatment episodes using difference-in-differences methods. They found that opioid treatment programs were 45.4 percentage points more likely to accept Medicare after the policy, nearly doubling pa

Diliberti et al. (2026) examined whether stricter school cell phone policies reduce students’ cell phone use during the school day. They analyzed survey responses from 774 U.S. middle and high school students in the nationally representative RAND American Youth Panel, comparing students across five levels of policy strictness. They found that stricter policies substantially reduced phone use. About 84% of students in schools with the most lenient policies checked their phones

Unrath et al. (2026) asked whether unconditional state child tax credits can reduce child poverty without substantially reducing parental employment. They used American Community Survey data, Supplemental Poverty Measure data, tax simulations, and labor supply estimates from recent state child tax credit studies to model the effects of different credit amounts and income phaseouts. They found that a $1,000 credit per child, phased out beginning at $50,000 for single filers, w

Swiderski and McDonnell (2026) examined whether students who begin at a community college have different long-term educational, occupational, and wage outcomes than similar students who start at a four-year college. They analyzed data from the National Longitudinal Survey of Youth 1997 (NLSY97), linked to O*NET occupational data, and compared similar students using propensity score weighting. They found that community college starters were more than 20 percentage points less

Olenski (2025) examined whether nursing home closures harm displaced long-stay residents or improve their long-term outcomes by moving them to better facilities. He analyzed nationwide administrative data on all long-stay U.S. nursing home residents, including 1,104 nursing home closures, using a matched difference-in-differences design. He found that closures increased short-term mortality by 1.18 percentage points, a 16.3% increase over the baseline quarterly mortality rate

Amuedo-Dorantes and Wang (2026) examined whether the economic and social benefits of the Deferred Action for Childhood Arrivals (DACA) program persisted after the Trump administration’s 2017 effort to end the program created prolonged policy uncertainty. They analyzed 2008–2022 American Community Survey data (excluding 2020) using difference-in-differences and event-study methods to compare DACA-eligible and ineligible undocumented immigrants. They found that early labor mark

Feigenberg and Miller (2025) examine whether police officers discriminate against low-income motorists during traffic stops and searches. They analyze more than 11 million traffic stops conducted by the Texas Highway Patrol between 2009 and 2015, linking motorists to measures of household income and vehicle status. They find large class disparities in policing. Motorists in the bottom income quintile were searched in 2.5% of stops, compared with 1.1% for those in the top quin

Bor et al. (2026) examined which causes of death account for the large number of excess deaths in the United States compared with 17 other high-income countries between 1999 and 2022. They analyzed more than 63.5 million U.S. deaths using mortality data from the World Health Organization Mortality Database. They found that the United States experienced about 12.7 million excess deaths during the study period, rising from 346,166 in 1999 to 905,159 in 2022. In 2022, circulator

Mayer, Méjean, and Thoenig (2026) examined whether credible threats of economic sanctions can deter war, using the Russia–Ukraine conflict as a case study. They combined international trade data from 1995–2021 with a quantitative model linking trade, diplomacy, and the probability of armed conflict. Their analysis found that Ukraine’s reduced economic dependence on Russia after 2014 lowered the economic costs of war and increased the predicted risk of conflict by more than 5