Abstract
This paper highlights the variable intensity of selection pressure on firms. Failing to include a theory of selection pressure in assessing a firm's performance can lead to ambiguous or incomplete judgements on the rationales of the firm's success. Building on previous threads of literature (population ecology, evolutionary economics, and the dynamic resource-based view of the firn), this paper paves the way for a unified theory of selection through seven research propositions. Emphasis is placed on the fact that managers can use the determinants of selection strategically, either to avoid the direct pressure of selection or to pass it on competitors.