Foreign Competition along the Quality Ladder, joint with Gabriel Smagghue
  Conditionally accepted, The Economic Journal, August 2022
  Latest version

We document that firms with low prices are more impacted by the rise of low-cost competition, even within narrowly defined product categories. To explain this pattern, we propose an empirical model of trade with random-coefficients demand and endogenous product quality. Unlike commonly used demand systems (e.g. CES, nested logit), this model generates rich substitution patterns across producers and implies an "escape-competition" effect: in response to low-cost competition, firms may upgrade their product quality to reach segments of the market that are less exposed. The estimation, using trade data from French shoe exporters, reveals significant heterogeneity in consumer preferences based on income and unobservable characteristics. Using the estimated model to quantify the unequal impact of the "China shock", we find that Chinese competition was significantly more damaging to French firms at the bottom of the price distribution, and that quality upgrading had a limited role at mitigating the heterogenous impact of the shock.


An Empirical Dynamic Model of Trade with Consumer Accumulation
  American Economic Journal: Microeconomics Vol. 13, No. 4, November 2021, Pages 23-63.
  Published version, Latest Version, Replication package, Bibtex

Sunk entry costs have been identified as the main export barrier by standard dynamic models of trade. However, these large entry costs are inconsistent with the existence of many small new exporters with low survival rates in foreign markets. To reconcile these patterns, this paper develops a dynamic structural model of trade in which firms slowly accumulate consumers in foreign markets. Estimating the model using export data from individual firms and a particle Markov chain Monte Carlo estimator, the model correctly predicts lower survival rates for new exporters and estimates much lower entry costs of exporting - less than half of those estimated in the absence of consumer accumulation. Using simulations and out- of-sample predictions, I show that these results have important implications regarding the aggregate response of international trade to external shocks.


Estimating firm product quality with trade data, joint with Gabriel Smagghue
  Journal of International Economics, Volume 118, May 2019, Pages 217-232.
  Published version, Latest Version, Replication package, Bibtex
  Winner of the FREIT EIIT 2013 best graduate student paper.

We propose a new instrumental variable strategy to estimate product quality at the firm-level, using trade data. Interacting firm importing shares by country with real exchange rates (RER), we obtain a cost shifter that varies across firms and is arguably orthogonal to product quality. We use this import weighted RER as an instrument for export prices and we identify firm-level quality from residual export variations, after controlling for prices. Our quality estimates correlate sensibly to firm characteristics (e.g. wages) and to alternative measures of quality available for some rare sectors. By contrast, our estimates are not always consistent with prices, a popular proxy for quality. We show for instance that firms add products to their export portfolio when their quality increases, as expected, while simultaneously their prices decrease. This suggests that our empirical strategy, by delivering quality estimates which, unlike prices, are not polluted with productivity variations, should contribute to future research on the link between firm-level product quality and globalization.

Substitution Patterns in Gravity Models, November 2021 Slides
  Joint with Gabriel Smagghue

Gravity models of international trade often rely on preferences with constant elasticity of substitution (CES) across varieties. This assumption rules out any role for differentiation and impose homogenous effects of competition across countries. In this paper, we propose a simple estimation strategy to capture differentiation and generate more realistic substitution patterns across countries: we develop a 2SLS estimator that can account for stronger substitution between countries that are located nearby in the product space, or share similar characteristics. We show that this correction improves the predictions of gravity models by capturing strong substitutions between countries with similar price and proximity in space.


Voluntary and Involuntary Transitions in the Labor Market

The labor market consequences of trade shocks depend heavily on the ability of workers to reallocate across firms, sectors and space. In this paper, I quantify these adjustment costs by studying workers’ trajectories following a change in employer. Unlike previous studies, I use administrative data from France that distinguish voluntary transitions from involuntary transitions for laid off workers. I incorporate these involuntary transitions in a model of job search to account for the inertia in workers’ decisions and better estimate the true costs of switching jobs. Finally, I examine the implications of these new estimates on the reallocation forces following a trade shock.

Microeconomics (SA.300.700), Syllabus
Fall 2016, Fall 2017, Spring 2018, Fall 2018, Fall 2019, Summer 2020, Fall 2020

Advanced Microeconomics (SA.310.700), Syllabus
Summer 2018