The study of causes and consequences of various forms of international firm activities is a very active sub-field of international economics. Micro-economic models of internationally active heterogeneous firms (surveyed by Redding (2011)) guide micro-econometric studies (surveyed by Wagner (2012)) that use longitudinal data at firm level to investigate empirically the testable implications of these models; stylized facts uncovered by looking at the micro data help theorists to build formal models based on assumptions that are not at odds with the real world. Members of the International Study Group on Exports and Productivity—ISGEP contribute to this literature for many years, and they gather regularly to discuss new results at workshops. This special issue of the Review of World Economics contains eight papers presented as preliminary versions at the workshop held in September 2011 at the Leuphana University Lüneburg, Germany.1