The term innovation generally means ‘something new’ – and this monograph is an innovation in a sense that it provides the reader with some new insights into the consequences of innovation activities at the ?rm level. In recent years, the importance of innovations for improving competitiveness and stimulating economic growth has increasingly become the focus of public attention. The Federal Government, for instance, proclaimed 2004 as the ‘year of innovation’ and started several initiatives to foster innovation activities in Germany. This monograph is aimed at the empirical assessment of the impact of the int- duction of new products and processes on various ?rm performance measures using modern microeconometric techniques. This book represents the written part of my doctoral examinations at the Department of Economics at the University of Wur ¨ zburg which were c- cluded with the oral examinations on July 28, 2006. The completion of this thesis was only possible with the assistance and the promotion of numerous individuals and institutions. First of all, I want to express my gratitude to my supervisor Martin Kukuk for supporting my academic research. During all the time he put his trust in me and gave me su?cient freedom to realise my ideas. I would like to thank him and Prof. Dr. Norbert Schulz, who kindly accepted to take on the second report, for their critical comments and constructive suggestions.