The degree of geographic concentration of individual manufacturing industries in the U.S. has declined only slightly in the last twenty years. At the same time, new plant births, plant expansions, contractions and closures have shifted large quantities of employment across plants, firms, and...

This paper discusses the prevalence of Silicon Valley-style localizations of individual manufacturing industries in the United States. Several models in which firms choose locations by throwing darts at a map are used to test whether the degree of localization is greater than would be expected...

Many industries are geographically concentrated. Many mechanisms that could account for such agglomeration have been proposed. We note that these theories make different predictions about which pairs of industries should be coagglomerated. We discuss the measurement of coagglomeration and use...

Does academic economic research produce material of scientific value, or are academic economists writing only for clients and peers? Is economics scholarship uniquely insular? We address these questions by quantifying interactions between economics and other disciplines. Changes in the impact of...

This paper examines the dynamics of the gender gap in high math achievement over the high school years using data from the American Mathematics Competition. A clear gender gap is already present by 9th grade and the gender gap widens over the high school years. High-achieving students must...

Over the last three decades there has been a dramatic increase in the length of time necessary to publish a paper in a top economics journal. This paper documents the slowdown and notes that a substantial part is due to an increasing tendency of journals to require that papers be extensively...

This paper examines a competitive model of add-on pricing, the practice of advertising low prices for one good in hopes of selling additional products (or a higher quality product) to consumers at a high price at the point of sale. The main conclusion is that add-on pricing softens price...

A large literature following Hirsch (2005) has proposed citation-based indexes that could be used to rank academics. This paper examines how well several such indexes match labor market outcomes using data on the citation records of young tenured economists at 25 U.S. departments. Variants of...

This paper uses a new data source, American Mathematics Competitions, to examine the gender gap among high school students at very high achievement levels. The data bring out several new facts. There is a large gender gap that widens dramatically at percentiles above those that can be examined...

This paper examines a model in which advertisers bid for "sponsored-link" positions on a search engine. The value advertisers derive from each position is endogenized as coming from sales to a population of consumers who make rational inferences about firm qualities and search optimally....