Research
Partial Identification in Models with Selectivity: Application to Texas Direct
[Abstract] When outcomes are only observed for people who selected into a choice — like students who complete a specific set of courses before transferring — standard corrections for this selection bias often require strong, hard-to-justify assumptions about how people make that choice. This paper develops an approach, built on random set theory, that instead works with the full range of possibilities consistent with the data. Applying the method to Texas's community college transfer policies, I find that completing transfer curricula reduces credit loss after transfer, but accumulating extra credits beyond what's required can lower the odds of completing a bachelor's degree.
Publications
Variation in English learners' programmatic experiences and postsecondary trajectories
Language and postsecondary trajectories: How "ever-English learner" status predicts college outcomes
Working Papers
Two-sample two-stage least squares estimation of nonparametric models
[Abstract] This paper investigates nonparametric instrumental variable estimation in a data combination context, in which one dataset contains the outcome and instrumental variables, and the other contains the explanatory and instrumental variables. We develop an estimator for structural functions, derive its uniform convergence rate, and introduce a two-sample bootstrap method for uniform inference. The proposed estimator is equipped with procedures for adaptive estimation and for constructing honest, adaptive uniform confidence bands, thereby enhancing its practical value. Our simulations demonstrate that the proposed procedure enables estimation and inference from two incomplete datasets that are comparable to its full-variable benchmark. We apply our findings to examine the relationship between healthcare expenditures and household budgets among the elderly population in the U.S., combining data from the Medical Expenditure Panel Survey and the Consumer Expenditure Survey. We find that universal Medicare coverage does not eliminate meaningful variation in healthcare consumption according to household characteristics and spending capacity among the U.S. elderly population.
Developmental education reform and student outcomes at California community colleges: The role of transfer-level course enrollment
[Abstract] California's Assembly Bill 705 was intended to increase student success by maximizing access to transfer-level math and English coursework in the state's community colleges. These transfer-level courses are broadly comparable to college-level courses in other states, though California's placement reform mandated that most students have direct access to transferable (rather than associate degree-applicable) courses. Although prior research illustrates that the reform increased access, few studies have examined transfer-level course enrollment during the initial rollout — when colleges retained discretion over placement — and how that enrollment predicts students' short- and long-term outcomes. Using statewide administrative data and inverse probability weighted regression adjustment, we examined which students enrolled in transfer-level courses and whether such enrollment predicts academic progress up to 4 years later. Our findings offer insights into placement reform implementation, the role of early access to transfer-level coursework in shaping subsequent academic momentum, and the implications of uneven access during discretionary implementation.
Expanding access, advancing outcomes: Evidence from California's developmental education reform
[Abstract] California's AB705 reformed developmental education in the nation's largest community college system. The policy required colleges to maximize the probability that students complete transfer-level coursework within one year and to use high school academic measures for placement. Yet, AB705's impacts on college completion and transfer remain unclear. Using student-level statewide administrative data, we examine its effects on course completion, degree attainment, and vertical transfer. We find that following AB705, students with the lowest academic readiness — the policy's target — experienced greater gains in transfer-level credit accumulation, credential attainment, and university transfer within four years than their better-prepared peers.
Single-Crossing, Information Ordering, and Identification in Choice under Uncertainty
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