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...

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...

Competition in many important industries centers on investment in intellectual property. Firms engage in dynamic, Schumpeterian competition for the market, through sequential winner-take-all races to produce drastic innovations, rather than through static price/output competition in the market....

Over the past four decades, the U.S. economy has seen a decline in the share of young firms alongside a rise in the profit share of GDP. This paper explores how population aging contributes to these twin trends through a demand-side channel. The core hypothesis is that younger households exhibit...

This paper identifies exit barriers as a new reason for India's underdeveloped manufacturing sector. These barriers not only deter entry but also trap resources in unproductive firms. We document that Indian institutions generate such barriers and provide causal evidence of their effects. Using...

Interstate Highway openings were permanent, anticipated demand shocks that increased gasoline demand and sometimes shifted it spatially. We investigate supply responses to these demand shocks, using county-level observations of service station counts and employment and data on highway openings'...

We study the consequences of product and labor market reforms in a two-country model with endogenous producer entry and labor market frictions. We focus on the role of business cycle conditions and external constraints at the time of reform implementation (or of a credible commitment to it) in...

This paper explores the effects of labor and product market reforms in a New Keynesian, small open economy model with labor market frictions and endogenous producer entry. We show that it takes time for reforms to pay off, typically at least a couple of years. This is partly because the benefits...

In a standard multi-sector, heterogeneous-firm trade model the effect of tariffs on entry, especially in the presence of production linkages, can reverse the traditional positive optimal-tariff argument. We construct and employ a new, large, disaggregated tariff dataset and then apply a...

A vast theoretical literature shows that inefficient market structures may arise in free entry equilibria. The inefficiency may manifest itself in the number, variety, or quality of products. Previous empirical work demonstrated that excessive entry may obtain in local radio markets. Our paper...