The SSNIP test and Critical Loss Analysis are widely used tools for determining market definition in merger and sometimes other antitrust matters. However, the standard techniques used to test for a relevant antitrust market are incorrect when the firms in question operate two-sided platforms....

We study the grocery industry in Washington, DC, during the Great Depression using data from the 1929 Census of Distribution, a 1929-1930 survey by the Federal Trade Commission, and a 1935 business directory. We first document the differences between chains and independents in the Washington,...

I quantify the price effect of a low-cost entrant on retail prices using a case-study approach. I consider the effect of Wal-Mart entry on average city-level prices of various consumer goods by exploiting variation in the timing of store entry. The analysis combines two unique data sets, one...