Theory predicts that in markets with increasing returns, the number of differentiated products and resulting consumer satisfaction grow in market size. We document this phenomenon across 246 US radio markets. By a mechanism that we term 'preference externalities', an increase in the size of the...

Free entry into markets with decreasing average costs and differentiated products can result in an inefficient number of firms and suboptimal product variety. Because new firms and products draw their customers in part from existing products, concentration can affect incentives to enter as well...

In theory, free entry can lead to social inefficiency. When new products are substitutes for existing products, the business stolen from incumbents places a wedge between private and social benefits of entry. The business stealing effect can be offset if entry reduces prices or increases...

The ability of firms to reposition their products can determine the effects of demand shocks, mergers and policy interventions in differentiated product markets. This paper estimates a dynamic oligopoly model to measure repositioning costs in the commercial radio industry. Based on a set of...

In "Bowling Alone," Putnam (1995) famously argued that the rise of television may be responsible for social capital's decline. I investigate this hypothesis in the context of Indonesian villages. To identify the impact of exposure to television (and radio), I exploit plausibly exogenous...

Markets are generally thought to avoid problems, such as tyranny of the majority, that arise when allocation is accomplished through collective processes. Yet, with fixed costs, differentiated product markets deliver only products desired by substantial constituencies. When consumers share...

We propose an approach to measuring the state of the economy via textual analysis of business news. From the full text content of 800,000 Wall Street Journal articles for 1984{2017, we estimate a topic model that summarizes business news as easily interpretable topical themes and quantifies the...