Research on business groups -legally independent firms tied together in a variety of formal and informal ways -is accelerating. Through meta-analytical techniques employed on a database of 141 studies covering 28 different countries, we synthesize this research and extend it by testing several new hypotheses. We find that affiliation diminishes firm performance in general, but also that affiliates are comparatively better off in contexts with underdeveloped financial and labor market institutions. We also trace the affiliation discount to specific strategic actions taken at the firm and group levels. Overall, our results indicate that affiliate performance reflects complex processes and motivations.The past decade has witnessed a surge in research regarding the performance of business groups (BGs), which Khanna and Rivkin (2001) define as "firms which though legally independent, are bound together by a constellation of formal and informal ties and are accustomed to taking coordinated action" (p. 47). Three points of consensus are apparent in this body of work. First, BGs are ubiquitous in many countries with types such as Japanese Keiretsus and Zaibatsu