<xref ref-type="bibr" rid="b25">Shimer (2005)</xref> pointed out that although we have a satisfactory theory of why some workers are unemployed at any given time, we don't know why the number of unemployed workers varies so much over time. The basic Mortensen--Pissarides model does not generate nearly enough volatility in...

There is a large body of evidence indicating that cross-country differences in income levels are associated with differences in productivity. If workers are much more productive in one country than in another, restrictions on immigration lead to large efficiency losses. The paper quantifies...

Most developed countries have foreign aid programs that aim to alleviate poverty and foster economic growth in less developed countries, but with very limited success. A large body of evidence indicates that the root of the economic development problem is cross-country differences in the...

The Lagos-Wright model-a monetary model in which pairwise meetings alternate in time with a centralized meeting-has been extensively analyzed, but always using particular trading protocols. Here, trading protocols are replaced by two alternative notions of implementability: one that allows only...

Abstract In the U.S. there are large differences across States in the extent to which college education is subsidized, and there are also large differences across States in the proportion of college graduates in the labor force. State subsidies are apparently motivated in part by the perceived...

In the theory of competitive markets, agents act as if they do not affect prices. By analogy with the language of econometrics, agents may be said to take prices as "exogenously given," which suggests that prices are econometrically exogenous in individual behavioral equations. This involves...