We construct an equilibrium model of firm diversification to show that the main empirical findings about firm diversification and performance are consistent with the maximization of shareholder value. In our model, diversification allows a firm to explore better productive opportunities while...

This paper extends the Q-theory of investment to capital goods with arbitrary efficiency profiles. Under the assumption of geometric economic depreciation employed by the traditional Q-theory, a firm's replacement cost of assets-in-place is independent of their vintage composition and can be...