We model and estimate the value of corporate risk management. We show how risk management can add value when revenues and costs are nonlinearly related to prices and estimate the model by regressing quarterly firm sales and costs on the second and higher moments of output and input prices. For a sample of 34 oil refiners, we find that hedging concave revenues and leaving concave costs exposed each represent between 2% and 3% of firm value. We validate our approach by regressing Tobin's q on the estimated value and level of risk management and find results consistent with the model.

Acquiring‐firm shareholders lost 12 cents around acquisition announcements per dollar spent on acquisitions for a total loss of $240 billion from 1998 through 2001, whereas they lost $7 billion in all of the 1980s, or 1.6 cents per dollar spent. The 1998 to 2001 aggregate dollar loss of acquiring‐firm shareholders is so large because of a small number of acquisitions with negative synergy gains by firms with extremely high valuations. Without these acquisitions, the wealth of acquiring‐firm shareholders would have increased. Firms that make these acquisitions with large dollar losses perform poorly afterward.