Which investment model best fits firm-level data? To answer this question we estimate alternative models using Compustat data. Surprisingly, the two best-performing specifications are based on Hayashi's (1982) model. This model's foremost implication, that Q is a sufficient statistic for...

This paper derives closed-form solutions for the investment and market value, under uncertainty, of competitive firms with constant returns to scale production and convex costs of adjustment. Solutions are derived for the case of irreversible investment as well as for reversible investment....

Capital investment decisions must recognize the limitations on the firm's ability later to sell off or expand capacity. This paper shows how opportunities for future expansion or contraction can be valued as options, how this valuation relates to the q-theory of investment, and how these options...

Which investment model best fits firm-level data? To answer this question we estimate alternative models using Compustat data. Surprisingly, the two best-performing specifications are based on Hayashi's (1982) model. This model's foremost implication, that Q is a sufficient statistic for...

This paper extends the theory of investment under uncertainty to incorporate fixed costs of investment, a wedge between the purchase price and sale price of capital, and potential irreversibility of investment. In this extended framework, investment is a non-decreasing function of q, the shadow...

When investment decisions cannot be reversed and returns to capital are uncertain, the firm faces a higher user cost of capital than if it could reverse its decisions. This higher user cost tends to reduce the firm's capital stock. Opposing this effect is the irreversibility constraint itself:...

The best predictor of current investment at the firm level is lagged investment. This lagged-investment effect is empirically more important than the cash-flow and Q effects combined. We show that the specification of investment adjustment costs proposed by Christiano, Eichenbaum and Evans...

The best predictor of current investment at the firm level is lagged investment. This lagged-investment effect is empirically more important than the cash-flow and Q effects combined. We show that the specification of investment adjustment costs proposed by Christiano, Eichenbaum and Evans...

Despite a large measured college premium, roughly one-third of all high-school graduates currently do not enroll in any form of college. Moreover, while recent increases in the premium have been accompanied by increases in enrollment, college attainment has remained flat. Our paper studies the...