My guest today is Karl Smith, he is the director of economic research at the Niskanen center. Our topic for today will be market power. Karl has written a series of posts on the Niskanen center blog discussing markups and market power. The debate was sparked by a paper by Loecker and Eeckhout that claimed that average markups in the American economy had risen from 18 percent in 1980 to 67 percent today. There are many different interpretations one might have for this data. What Karl points out is that these markups have mainly risen among smaller firms. Wal-Mart has very low markups, but niche specialty firms such as the local vegan café have relatively high markups. This makes sense in the context of monopolistic competition, where consumers pay a small premium in return for greater product differentiation. Noah Smith had this response to Karl's article: "Robin Hanson and Karl Smith both have posts responding to De Loecker and Eeckhout’s paper and attacking the Market Power Story. Both give reasons why they think rising markups indicate monopolistic competition, rather than entry barriers. But both seem to forget that monopolistic competition causes deadweight loss. Just because it has the word 'competition' in it does NOT mean that monopolistic competition is efficient. It is not." As Tyler Cowen points out, this is not necessarily the case. What is inefficient in a partial equilibrium model may not be inefficient in a general equilibrium model.