Nirav Mehta

Research Fields

Empirical microeconomics, structural estimation, public economics, empirical contracts, economics of education, and health economics.

Research Projects

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# title topic status
1
Competition in Public School Districts: Charter School Entry, Student Sorting, and School Input Determination
Mehta, Nirav. International Economic Review, 58(4), 1089-1116. 2017.

This paper develops and estimates an equilibrium model of charter school entry, school input choices, and student school choices. The structural model renders a comprehensive and internally consistent picture of treatment effects when there may be general equilibrium effects of school competition. Simulations indicate that the mean effect of charter schools on attendant students is positive and varies widely across locations. The mean spillover effect on public school students is small but positive. Lifting caps on charter schools would more than double entry but reduce gains for attendant students.

Link to working paper version: pdf (updated 7/2016)


education forthcoming/published
2
Ability Tracking, School and Parental Effort, and Student Achievement: A Structural Model and Estimation
(with Chao Fu)
Forthcoming at the Journal of Labor Economics

We develop and estimate an equilibrium model of ability tracking. In the model, a school chooses how to allocate students into tracks based on their ability and chooses track-specific inputs. Parents choose parental effort in response. We estimate the model using data from the ECLS-K. We use the estimated model to first examine the effects of disallowing tracking on school and parental inputs and student achievement. We then examine how policies that change proficiency standards affect equilibrium tracking, school inputs, parental effort and student achievement.

Link to working paper version: pdf (updated 3/2017)


education forthcoming/published
3
An Economic Approach to Generalizing Findings from Regression-Discontinuity Designs
Forthcoming at the Journal of Human Resources

Regression-discontinuity (RD) designs estimate treatment effects at a cutoff. This paper shows what can be learned about average treatment effects for the treated (ATT), untreated (ATUT), and population (ATE) if the cutoff was chosen to maximize the net gain from treatment. The ATT must be positive. Without capacity constraints, the RD estimate bounds the ATT from below and the ATUT from above, implying bounds for the ATE, and optimality of the cutoff rules out constant treatment effects. Testable implications of cutoff optimality are derived. Bounds are looser if the capacity constraint binds. The results are applied to existing RD studies.

Link to working paper version: pdf (updated 12/2017)


education forthcoming/published
4
The Potential Output Gains from Using Optimal Teacher Incentives: An Illustrative Calibration of a Hidden Action Model
Forthcoming at the Economics of Education Review

This paper examines the potential output gains from the implementation of optimal teacher incentive pay schemes, by calibrating the Hölmstrom and Milgrom (1987) hidden action model using data from Muralidharan and Sundararaman (2011), a teacher incentive pay experiment implemented in Andhra Pradesh, India. Findings suggest that the introduction of optimal individual incentive-pay schemes could result in very large increases in output, about six times the size of the significant results obtained in the experiment.

Link to working paper version: pdf (updated 4/2018)


empirical contracts and education forthcoming/published
5
Social Interactions, Mechanisms, and Equilibrium: Evidence from a Model of Study Time and Academic Achievement
(with Tim Conley, Ralph Stinebrickner, and Todd Stinebrickner)
Under review

We develop and estimate a model of student study time on a social network. The model is designed to exploit unique data collected in the Berea Panel Study. Study time data allow us to quantify an intuitive mechanism for academic social interactions: own study time may depend on friend study time in a heterogeneous manner. Social network data allow us to embed study time and resulting academic achievement in an estimable equilibrium framework. We develop a specification test that exploits the equilibrium nature of social interactions and use it to show that novel study propensity measures mitigate econometric endogeneity concerns.

Link to paper: pdf (updated 10/2017)


education under review
6
Measuring Quality for Use in Incentive Schemes: The Case of “Shrinkage” Estimators
Accepted at Quantitative Economics

Researchers commonly “shrink” raw quality measures based on statistical criteria. This paper studies when and how this transformation’s statistical properties would confer economic benefits to a utility-maximizing decisionmaker across common asymmetric information environments. I develop the results for an application measuring teacher quality. The presence of a systematic relationship between teacher quality and class size could cause the data transformation to do either worse or better than the untransformed data. I use data from Los Angeles to confirm the presence of such a relationship and show that the simpler raw measure would outperform the one most commonly used in teacher incentive schemes.

Link to paper: pdf (updated 7/2018)


empirical contracts and education forthcoming/published
7
After-hours Incentives and Emergency Department Visits: Evidence from Ontario
(with Koffi Ahoto Kpelitse, Rose Anne Devlin, Lihua Li, and Sisira Sarma)
Revise and resubmit at Canadian Journal of Economics

One important component of the primary care reform in Ontario, Canada is to incentivize physicians to work “after hours.” The objective of this policy is to reduce visits to hospital emergency departments and improve access to core primary care services. Empirically, evidence on this link is ambiguous. We suggest reasons for this ambiguity, and then harness rich administrative data from Ontario to carefully investigate if and why after-hours incentives affect ED usage. The data cover visits to physicians' offices and ED visits from 2004 to 2013, a period with exogenous changes in after-hours incentives. We find strong evidence that ED visits are reduced as a result of these incentives---and that this reduction is in nonurgent patients. We also estimate a potential health system savings associated with this redistribution of patient care.

Link to paper: pdf (updated 2/2018)


health revise and resubmit
8
Time-Use and Academic Peer Effects in College
Mehta, Nirav, Ralph Stinebrickner, and Todd Stinebrickner. Accepted at Economic Inquiry.

This paper examines academic peer effects in college. Unique new data from the Berea Panel Study allow us to focus on a mechanism wherein a student’s peers affect her achievement by changing her study effort. Although the potential relevance of this mechanism has been recognized, data limitations have made it difficult to provide direct evidence about its importance. We find that a student’s freshman grade point average is affected by the amount her peers studied in high school, suggesting the importance of this mechanism. Using time diary information, we confirm that college study time is actually being affected.


education forthcoming/published
9
Family Physician Remuneration Schemes and Specialist Referrals: Quasi-experimental Evidence from Ontario, Canada
Sarma S, Mehta N, Devlin RA, Kpelitse KA, Li L. Health Economics. 2018;1-17.
“early-view” link




health forthcoming/published
10
Optimal Contracting with Altruistic Agents: A Structural Model of Medicare Reimbursements for Dialysis Drugs

We study physician agency and optimal reimbursement policy in the context of an expensive medication (“EPO”) used with dialysis. Using Medicare claims data we estimate a model of treatment decisions, in which physicians are partially altruistic and value both their own compensation and their patients’ health. We then use the recovered parameters of the physician utility function in combination with results from contract theory to derive and simulate optimal payments to physicians for service provision. Comparing the optimal contract with actual contracts suggests tractable improvements in payment policy.


empirical contracts and health In-progress