Working papers

Academic version - NBER Working Paper (with Samuel Nitkin)

Summary version - Policy brief

Abstract - Private tutoring chains like Kumon and Sylvan have expanded rapidly in recent decades. Combining data on business locations, household spending, and district test scores, we study who uses these centers and how they affect academic skills. Nearly half of tutoring users are from the top income decile, with Asian and White households five and two times as likely to purchase tutoring as Black and Hispanic households. A staggered differences-in-differences design shows the opening of a district's first chain center raises district-wide math and reading scores by 0.02-0.03 standard deviations, at a much lower cost than public spending typically producing similar gains. Math effects are largest for White and Asian students, so that center entry widens racial achievement gaps, though less so in more racially integrated districts. These private investments help their users, deepen educational inequality, and shape outcomes by which state accountability systems and families judge schools.

Academic version - NBER working paper (with A. Patrick Behrer, J. Parker Goyer, and R. Jisung Park)

Summary version - Policy brief

Abstract - Nearly the entire world’s population breathes air exceeding WHO pollution guidelines, but the extent to which that exposure impairs the accumulation of human capital is not well understood. We study this using longitudinal PSAT data on nearly 10 million U.S. high school students, comparing the same student’s scores across attempts preceded by differing air quality and instrumenting for local PM2.5 with smoke from distant wildfires. A year of observed pollution exposure reduces learning by 0.04-0.06 standard deviations, or 14-19% of typical annual score growth. The damage comes almost entirely from moderate pollution days (8–12 μg/m3), below the EPA’s historical standard, and from exposure during the school year rather than summer, pointing to instructional disruption as a mechanism. Effects are three times larger in disadvantaged schools and among Black and Hispanic students, who are harmed more by the same exposure. Exposure to air pollution widens achievement gaps.

Academic version - Working paper (with Stephanie Coffey, Amy Ellen Schwartz, Leanna Stiefel, Marcus Winters, and Yunee Yoon)

Summary version - Policy brief

Media highlights - Chalkbeat

Academic version - Working paper (with Yue Bao and Jonathan Smith)

Abstract - Graduate education offers substantial earnings and employment advantages, yet completion rates remain deeply unequal across racial and socioeconomic lines. Using Georgia’s longitudinal administrative data linking all public high school graduates to their postsecondary outcomes, we document who enrolls in and completes graduate school and the stages of the educational pipeline at which disparities arise. A funnel decomposition reveals that the White-Black gap is driven almost entirely by undergraduate and graduate persistence, not access, and that economically disadvantaged students face cumulative barriers at every stage. However, Black students are equally likely as comparably academically prepared White students to complete graduate degrees. Undergraduate major choice explains roughly 40 percent of the gender gap in graduate completion, much more so than undergraduate institutional choice, but plays a more limited role in racial and socioeconomic gaps. These findings suggest that closing racial and income disparities in graduate degree attainment requires addressing unequal academic preparation and persistence within educational programs, not simply expanding access.

Academic version - NBER working paper (with Joseph Winkelmann)

Abstract - Declining U.S. college enrollments over the past 15 years have triggered questions about the health of the postsecondary sector. Using institution-level data, we make four points. First, such declines are driven not by the four-year sector but by two-year community colleges, which have apparently shrunk by over 30% since the peak of the Great Recession. Second, over one-third of this apparent decline is an artifact of some community colleges being reclassified as offering four-year degrees. Third, pre-Great Recession data shows a 1 percentage point increase in the local unemployment rate increases first-time community college enrollment by 2 percent, suggesting many students are on the margin between community college and job opportunities. For-profit college enrollments are similarly countercyclical, while public and private four-year college enrollments appear acyclical. Our estimates suggest that strengthening labor markets explain about 60% of the post-Great Recession decline in first-time community college enrollment. Fourth, students whose enrollment decisions are most sensitive to labor market conditions appear unlikely to have completed a degree. Though declining community college enrollments are a challenge for postsecondary institutions, it is less clear whether they signal a problem for students on the margin of enrollment.

Media highlights - Chalkbeat, Chronicle of Higher Ed, Inside Higher Ed, Education Next (podcast)

Academic version - NBER Working Paper 20221

Summary version - Education Next

Media highlights - Washington Post, CNN, BBC, Slate, The Atlantic, Vox, Weather Channel, WGBH, Brian Lehrer, WBUR, WNYC, Chalkbeat