Most economists intuitively consider purchasing power parity (PPP) to be true. Nevertheless, quite surprisingly, the empirical literature is not very supportive for PPP. In this paper, however, we find evidence in favor of PPP using a new test. The test is embedded in a Markov regime-switching...

In this paper, a worker's productivity is assumed to depend on his own quality and on the average quality of other workers in the same country. The external effects associated with worker quality give rise to increasing returns to average worker quality. As a result, free migration generally...