This study tests for financial constraints on R&D investment and how they differ from capital investment. To identify constraints in the access to external capital, we employ a credit rating index. Our models show that internal constraints, measured by mark-ups, are more decisive for R&D than...

This study presents the first empirical test with German establishment level data of a hypothesis derived by Helpman et al. (2004) in a model that explains the decision of heterogeneous firms to serve foreign markets either through exports of foreign direct investment: only the more productive...