Market definition is essential to merger analysis. Because no standard approach to market definition exists, opposing parties in antitrust cases often disagree about the extent of the market. These differences have been particularly relevant in the hospital industry, where the courts have denied...

Cross-subsidies are often considered the principal mechanism through which hospitals provide unprofitable care. Yet, hospitals' reliance on and extent of cross-subsidization are difficult to establish. We exploit entry by cardiac specialty hospitals as an exogenous shock to incumbent hospitals'...

Because consumer reviews leverage the wisdom of the crowd, the way in which they are aggregated is a central decision faced by platforms. We explore this "rating aggregation problem" and offer a structural approach to solving it, allowing for (1) reviewers to vary in stringency and accuracy, (2)...

This study examines the relationship between child weight and fast food and fruit and vegetable prices and the availability of fast food restaurants, full-service restaurants, supermarkets, grocery stores and convenience stores. We estimate cross-sectional and individual-level fixed effects (FE)...

We demonstrate that data from digital platforms such as Yelp have the potential to improve our understanding of gentrification, both by providing data in close to real time (i.e. nowcasting and forecasting) and by providing additional context about how the local economy is changing. Combining...

Amenities such as good food, attentive staff, and pleasant surroundings may play an important role in hospital demand. We use a marketing survey to measure amenities at hospitals in greater Los Angeles and analyze the choice behavior of Medicare pneumonia patients in this market. We find that...

We study the impact of the minimum wage on firm exit in the restaurant industry, exploiting recent changes in the minimum wage at the city level. We find that the impact of the minimum wage depends on whether a restaurant was already close to the margin of exit. Restaurants with lower ratings...

We examine an untested hypothesis that posits that null results in early studies examining the economic impacts of smoking bans were driven by sample selection. Early adopters could better absorb the shock of bans, but among worse selected late adopters bans would adversely impact bars and...

We present a structural model of firm growth, learning, and survival and consider its identification and estimation. In the model, entrepreneurs have private and possibly error-ridden observations of persistent and transitory shocks to profit. We demonstrate that the model's parameters can be...