WORK IN PROGRESS:
​​
"The Impact of Risk-Based Pricing and Refinancing on the Student Loan Market"
Advances in data-driven underwriting have both efficiency and equity implications.  In the $1.3 trillion student loan market, private lenders offer a growing distribution of risk-based interest rates, while the federal loan program sets a uniform price. I measure changes in consumer surplus that occur as low-risk types refinance out of the government pool into the private market.  I use a dataset from an online refinancer to estimate a structural model that relates borrowers' repayment choices to interest rates.  I estimate refinancing increases low-risk surplus by $1,302, and show substantial distortionary costs (32% of the average transfer) under a pooled, uniform interest rate.  To maintain access to the current uniform rate, the government must subsidize high-risk borrowers $1,507 on average.

"Loan Guarantees and Credit Supply", with Olivia Kim and Constantine Yannelis
The efficiency of federal lending guarantees depends on whether guarantees increase lend- ing supply, or simply act as a subsidy to lenders. We estimate the elasticity of lending supply to loan guarantees by exploiting notches in guarantee rates for loans made by the Small Business Administration. We find significant bunching on the side of the threshold with higher loan guarantees, and estimate an elasticity of lending supply to loan guarantees of approximately 5. We find that the excess mass is greater in years when guarantees are higher, and placebo estimates indicate no bunching in years when the guarantees notch is eliminated. 

"Market Power in Small Business Lending: A Two Dimensional Bunching Approach", with Ernest Liu
While bank lending is an important financing channel for small firms, banks in the U.S. have substantial market power. What are the efficiency implications and policy remedies to bank concentration? We build a model of bank competition with endogenous interest rates, loan size, and take-up. We estimate the model using the universe of loans made through the Small Business Administration (SBA). Our novel identification strategy builds on and extends the “bunching” literature that uses kinks and notches to identify key elasticities, utilizing a discontinuity in SBA’s interest rate cap. We find banks capture at least 30% of the surplus in a majority of lending markets. Imposing a uniform interest rate cap of 5% would increase borrower welfare by 9%, but also cause substantial rationing. While the guarantee subsidy program used by the SBA raises borrower surplus by 17%, we find that banks capture the majority of increase in surplus.

“Student Loan Prepayment and Risk Pooling”, with Thomas Conkling and Christa Gibbs
Prepayment rates are relatively high in the student loan market.  In equilibrium this can lead to lenders setting higher equilibrium interest rates for two related reasons: borrowers in general prepay capital early, and furthermore these prepayments can generate adverse changes in the risk composition of the pool. In this paper we document the empirical joint distribution of prepayment rates and changes in risk in the student loan origination market. We use a loan-year level panel of individuals with student loans to measure how observable risk (proxied by credit score and delinquency metrics) evolves over time for individuals who look similar at origination, and how this evolution in risk correlates with repayment speed.  We find a strong positive relationship between changes in risk and prepayment rates.  We then use this information to estimate how equilibrium interest rates would change in the presence of a prepayment penalty, an origination fee, and other counterfactual policies that would allow lenders to enforce pooling during repayment.
"Are Borrowers Credit Constrained? Evidence From the Expansion of Federal Loan Limits" with Constantine Yannelis
​

PUBLISHED WORK:

​"Messaging and the Mandate: The Impact of Consumer Experience on Health Insurance Enrollment Through Exchanges"
Joint work with Ben Handel, Jonathan T. Kolstad, and Neale Mahoney.  American Economic Review: Papers and Proceedings 2015, 105(5):105-109