Market definition and market power are central features of competition law and practice but pose serious challenges. On one hand, market definition suffers decisive logical infirmities that render it infeasible, unnecessary, and counterproductive, and the practice of stating market power...

This paper explores how different margins of market share are related to markups. Using merged microdata on producers and consumers, we document that a firm's market share is mainly related to its number of customers, while its price-cost markup is associated only with its average sales per...

This paper analyzes the relation between exogenous changes in commodity export prices and the real exchange rate in a monetary economy. The traditional Dutch?Disease case is extended, and the monetary consequences of an export boom are explored. It is shown that commodity export booms can...

In several countries temporary terms of trade improvements have led to a deterioration of the current account. Furthermore, many of these countries failed to attain greater post-boom growth rates. The point we make is that the structure of the fiscal process is critical in determining outcomes....

How does a firm's market power in existing products affect its incentives to innovate? We explore this fundamental question using granular project-level and firm-level data from the pharmaceutical industry, focusing on a particular mechanism through which incumbent firms maintain their market...

We construct measures of industry performance and welfare in the U.S. car and light truck market from 1980-2018. We estimate a differentiated products demand model for this market using product level data on market shares, prices, and product characteristics, and consumer level data on...

We study how inertia interacts with market power and adverse selection in managed competition health insurance markets. We use consumer-level data to estimate a model of the California ACA exchange, in which four firms dominate the market and risk adjustment is in place to manage selection. We...

Might firms' use of data create market power? To explore this hypothesis, we craft a model in which economies of scale in data induce a data-rich firm to invest in producing at a lower marginal cost and larger scale. However, the model uncovers much richer interactions between data, welfare and...

To answer the question whether managers are paid for market power, we propose a theory of executive compensation in an economy where firms have market power, and the market for man- agers is competitive. We identify two distinct channels that contribute to manager pay in the model: market power...

This paper compares alternative liability rules for allocating losses from defective products when consumers under- estimate these losses and producers may have some market power. If producers do not have any market power, the rule of strict liability .leads to both the first-best accident...