We document that the recent decline in aggregate volatility has been accompanied by a large increase in firm level risk. The negative relationship between firm and aggregate risk seems to be present across industries in the US, and across OECD countries. Firm volatility increases after...

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...

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 et al. (2005) predicts the...

Recurrent intervals of inattention to the stock market are optimal if consumers incur a utility cost to observe asset values. When consumers observe the value of their wealth, they decide whether to transfer funds between a transactions account from which consumption must be financed and an...

Do investment models fit firm-level data? - which model fits best? To answer this question we estimate alternative models using Compustat data. We find that both a version of the Hayashi (1982) and a model with decreasing returns to scale in production fit firm-level data very well. Our...

Investment is characterized by costly reversibility when a firm can purchase capital at a given price and sell capital at a lower price. We derive an explicit analytic solution for optimal investment by a firm facing costly reversibility. In addition, we derive a local approximation to the...