This is an invited chapter for the forthcoming Volume 4 of the Handbook of Industrial Organization. We present empirical models of demand and supply in differentiated products industries with an emphasis on the key ideas arising from the recent applied literature. We start with a discussion of...

Increasingly, retailers have access to better pricing technology, especially in online markets. Using hourly data from five major online retailers, we show that retailers set prices at regular intervals that differ across firms. In addition, faster firms appear to use automated pricing rules...

This papers analyzes dispersion in the prices that an airline charges to different customers on the same route. Such variation in airlines fares is substantial: the expected absolute difference in fares between two of an airline's passengers on a route averages thirty-six percent of the...

How strong are strategic complementarities in price setting across firms? In this paper, we provide a direct empirical estimate of firm price responses to changes in prices of their competitors. We develop a general framework and an empirical identification strategy to estimate the elasticities...

Regulators around the world are discussing, or taking action to limit, self-preferencing by large platforms. This paper explores Amazon's search rankings of its own products as the European Union's Digital Markets Act (DMA) was coming into effect. Using data on over 8 million Amazon search...

In government-sponsored health insurance, subsidy design affects market outcomes. First, holding premiums fixed, subsidies determine insurance uptake and average cost. Insurers then respond to these changes, adjusting premiums. Combining data from the first four years of the California ACA...

Entry represents a fundamental threat to cartels engaged in price fixing. We study the extent and effect of this behavior in the largest price fixing case in US history, which involves generic drugmakers. To do so, we link information on the cartel's internal operations to regulatory filings and...

We study the evolution of profits, investment and market shares in US industries over the past 40 years. During the 1990's, and at low levels of initial concentration, we find evidence of efficient concentration driven by tougher price competition, intangible investment, and increasing...

I study how online competition, with its algorithmic pricing technologies and the transparency of the Internet, can change the pricing behavior of large retailers and affect aggregate inflation dynamics. In particular, I show that online competition has raised both the frequency of price changes...

The purpose of this paper is to understand the effects of endogenous markups and trade costs on the pricing behavior of exporters when firms are heterogeneous in productivity. Using new analytical distributions for markups under Bertrand competition, we uncover Ricardian patterns of export...