"Growth of technological variety offers more scope for the division of labor. And when a division of labor requires some specific training, the technological specificity of human capital grows and, with it, probably the firm specificity of that capital. We build a simple model that captures this...

This paper discusses the impact of a firm's technology portfolio on its market value. Two concepts are used to characterize a firm's portfolio: the number of technological fields and the degree of relatedness within the portfolio characterized by the amount of joint occurrences of patents in...