Research

Publications

1. "Powerful t-tests in the presence of nonclassical measurement error", Econometric Reviews (forthcoming)

2. "IV methods for Tobit models", Journal of Econometrics, Volume 235, Issue 2, August 2023, pages 1700-1724.

3. "Partially Identifying Competing Risks Models: an Application to the War on Cancer", Journal of Econometrics, Volume 234, Issue 2, June 2023, pages 536-564 [Working paper version]

4. "COVID-19 Vaccination Mandates and Vaccine Uptake", Nature Human Behaviour, 6, 1615–1624, 2022  (2022 Impact Factor: 29.9)

5. "Vaccination strategies and transmission of COVID-19: evidence across advanced countries", Journal of Health Economics, Volume 82, March 2022, 102589

6. "An Adaptive Test of Stochastic Monotonicity", Econometric Theory, Volume 37, Issue 3, June 2021, pp. 495 - 536 

7. "Partial identification in nonseparable count data IV models", Econometrics Journal, Volume 23, Issue 2, May 2020, Pages 232–250

8. "Nonparametric instrumental variable estimation", 2018, Stata Journal, Volume 18 Number 4: pp. 937-950

Working Papers

1. "Nonparametric Estimation of Sponsored Search Auctions and Impacts of Ad Quality on Search Revenue", 2023 (R&R at Management Science)

Abstract : This paper presents an empirical model of sponsored search auctions in which advertisers are ranked by bid and ad quality. We introduce a new nonparametric estimator for the advertiser's ad value and its distribution under the `incomplete information' assumption. The ad value is characterized by a tractable analytical solution given observed auction parameters. Using Yahoo! search auction data, we estimate value distributions and study the bidding behavior across product categories. We find that advertisers shade their bids more when facing less competition. We also conduct counterfactual analysis to evaluate the impact of score squashing  (ad quality raised to power θ < 1) on the auctioneer's revenue. Our results show that product-specific score squashing can enhance auctioneer revenue at the expense of advertiser profit and consumer welfare.

2. "Semi-nonparametric Models of Multidimensional Matching: an Optimal Transport Approach", 2023 (coming soon!)

Abstract : This paper proposes empirically tractable multidimensional matching models that do not restrict distributions of observed characteristics, with a particular focus on worker-job matching. We establish identification of the parametrically specified production function as well as nonparametric equilibrium wage and matching functions using the theory of optimal transport. Our approach generalizes Lindenlaub (2017, Review of Economic Studies)'s model which imposes joint normality of characteristics of workers and jobs. We derive conditional moment restrictions from which model parameters and nonparametric functions of interest are obtained via semiparametrically efficient sieve-based estimation procedures. We revisit Lindenlaub's empirical application and show that, between 1990 and 2010, the U.S. economy experienced much larger technological progress favoring cognitive abilities than the original findings suggest. Furthermore, our more flexible model specifications provide a much better fit for patterns in the evolution of wage inequality.