We measure value creation by activist investors via structural estimation of a model of the choice between passive investment and activism. Our estimates imply that average returns following activist intent announcements consist of 74.8% expected value creation, or treatment, 13.4% stock picking, and 11.8% sample selection effects. Higher treatment values predict improvements in firm performance and lower proxy contest probabilities, whereas abnormal announcements returns do not, suggesting that our estimate identifies more effective activism campaigns. The evidence demonstrates the importance of using the joint distribution of investment strategies and announcement returns to recover the expected returns and costs of activism.

Theory has recently shown that corporate policies should depend on firms’ exposure to short- and long-lived cash flow shocks and the correlation between these shocks. We provide granular estimates of these parameters for Compustat firms using a new filter that uses only cash flow data and the theoretical restrictions of a canonical cash flow model. As predicted by theory, we find that the estimated parameters are strongly related to corporate liquidity and financing choices, that firms with a higher estimated correlation between shocks implement riskier policies, and that the sign of this correlation determines the cash flow sensitivity of cash.