Two economic theories that have had an immense impact on modern strategic management research are Porter's strategic positioning framework (SPF) and Williamson's transaction cost economics (TCE). While both theories have contributed to our understanding of strategic management and to the choice of strategy and structure, each theory offers managerial prescriptions that are incomplete at best. We contend that if followed in isolation, each theory can lead to inferior performance. This paper, which studies the international courier and small package (IC&SP) services in Japan, improves upon prescriptions from both theories by linking Porter's and Williamson's approaches. Our main proposition is contained in three relationships that predict a fit among three strategic choices: market position, resource profile, and organizational structure. We test our predictions with a three-stage, reduced-form, endogenous selfselection model. While our empirical methodology is complicated and relies on a multilevel analysis, the methodology is necessary both for analyzing a constellation of activities in the vertical chain and for assessing strategy, structure, and performance when data can be drawn from only a limited number of firms. Our results suggest that a firm's market position, resource profile, and organizational choice are related in ways predicted by a positioning-economizing perspective. To be sure, our study is ambitious and suffers from a number of limitations; nevertheless, it provides one of the first attempts to theoretically and empirically link Porter's SPF and Williamson's TCE.