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...

The paper studies the interaction between cyclical uncertainty and investment in a stochastic real option framework where demand shifts stochastically between three different states, each with different rates of drift and volatility. In our setting the shifts are governed by a three-state Markov...

A popular interpretation of the Rational Expectations/Efficient Markets hypothesis states that, if the hypothesis holds, then market valuations must follow a random walk. This postulate has frequently been criticized on the basis of empirical evidence. Yet the assertion itself incurs what we...

We develop a model of investment with financial constraints and use it to investigate the relation between investment and Tobin's q. Afirm is financed partly by insiders, who control its assets, and partly by outside investors. When their wealth is scarce, insiders earn a rate of return higher...