Resource-based theory examines performance differences of organizations based on their resources (Peteraf & Barney, 2003). The theory makes two main assumptions: (1) organizations within an industry may differ in their resources, and (2) these resources may not be perfectly mobile across organizations, so organizational differences in resources can be very long lasting (Barney, 1991). The theory seeks to explain how organizations maintain unique and sustainable positions in competitive environments (Hoopes, Madsen, & Walker, 2003). It focuses on efficiency-based differences, instead of on other ways in which organizations could be different, such as market power, collusion, or strategic behaviors (Peteraf & Barney, 2003).