This paper tests some of the predictions of recent advances in trade theory that have focused on different trade patterns of firms within the same sector. Helpman, Melitz and Yeaple (2005) develop a model in which innate productivity differences between firms determine the degree of...

This study provides empirical evidence for the economic rationality of wage rigidities. Theoretically wage rigidities can result from contracts, implicit contracts, from efficiency wages and from insider-outsider behaviour. Based on a survey of 801 firms strong support has been found for...