How firms compete for an advantage is among the most critical questions in Business Strategy. While several researchers link executives to key strategic outcomes, much less is understood on how the Upper-Echelon team drives the actual competitive behavior of the firm, which is manifested in the launching of observable and purposeful competitive actions within the marketplace.

Considering that competitive behavior research tends to overlook the importance of human assets, in general, and executive human assets, in particular, I explore how the knowledge, skills, and abilities of the Chief Executive (CEO), Top Management Team (TMT), and Board of Directors (BOD) impact a firm's competitive behavior. In addition, I examine how sources of Social Capital, or the relationships between these Upper-Echelon actors, influence a firm's competitive behavior. Moreover, I argue and test for the moderating influence of executive compensation on firm competitive behavior.

Applying relational demography to capture Human Capital and sources of Social Capital within the U.S. Pharmaceutical Industry, I find some empirical support that executives do, indeed, affect firm competitive behavior. Overall, the empirical evidence indicates that the Human Capital of the CEO, TMT, and BOD can influence all dimensions of a firm's Competitive Intensity. Unexpectedly and, contrary to prediction, executive dissimilarity (not similarity) tended to greatly influence a firm's Competitive Activity and Repertoire Complexity. Also, the moderating impact of executive bonus and incentive pay was largely supported.

This dissertation contributes to both the competitive behavior and Upper-Echelon literatures. Notably, this dissertation adds to the very limited work that attempts to theoretically link and empirically test for executive impact on firm competitive behavior. By so doing, it begins to open the "black box" on how human assets at the Upper Echelon affect strategic outcomes through a firm's competitive behavior.