Traditional real options models demonstrate the importance of the “option to wait” due to uncertainty over future shocks to project cash flows. However, there is often another important source of uncertainty: uncertainty over the permanence of past shocks. Adding Bayesian uncertainty over the permanence of past shocks augments the traditional option to wait with an additional “option to learn.” The implied investment behavior differs significantly from that in standard models. For example, investment may occur at a time of stable or decreasing cash flows, respond sluggishly to cash flow shocks, and depend on the timing of project cash flows.

The aggregate portfolio of actively managed U.S. equity mutual funds is close to the market portfolio, but the high costs of active management show up intact as lower returns to investors. Bootstrap simulations suggest that few funds produce benchmark‐adjusted expected returns sufficient to cover their costs. If we add back the costs in fund expense ratios, there is evidence of inferior and superior performance (nonzero true α ) in the extreme tails of the cross‐section of mutual fund α estimates.

We show that institutions that promote financial development ease borrowing constraints by lowering the collateral spread and shifting the composition of acceptable collateral towards firm‐specific assets. Collateral spread is defined as the difference in collateralization rates between high‐ and low‐risk borrowers. The average collateral spread is large but declines rapidly with improvements in financial development driven by stronger institutions. We also show that the composition of collateralizable assets shifts towards non‐specific assets (e.g., land) with borrower risk. However, the shift is considerably smaller in developed financial markets, enabling risky borrowers to use a larger variety of assets as collateral.

We characterize generalized disappointment aversion (GDA) risk preferences that can overweight lower‐tail outcomes relative to expected utility. We show in an endowment economy that recursive utility with GDA risk preferences generates effective risk aversion that is countercyclical. This feature comes from endogenous variation in the probability of disappointment in the representative agent's intertemporal consumption‐saving problem that underlies the asset pricing model. The variation in effective risk aversion produces a large equity premium and a risk‐free rate that is procyclical and has low volatility in an economy with a simple autoregressive endowment‐growth process.

Experimental evidence has consistently confirmed the ability of uninformed traders, even novices, to infer information from the trading process. After contrasting brain activation in subjects watching markets with and without insiders, we hypothesize that Theory of Mind (ToM) helps explain this pattern, where ToM refers to the human capacity to discern malicious or benevolent intent. We find that skill in predicting price changes in markets with insiders correlates with scores on two ToM tests. We document GARCH‐like persistence in transaction price changes that may help investors read markets when there are insiders.

We use exogenous variation in tax benefit functions to estimate firm‐specific cost of debt functions that are conditional on company characteristics such as collateral, size, and book‐to‐market. By integrating the area between the benefit and cost functions, we estimate that the equilibrium net benefit of debt is 3.5% of asset value, resulting from an estimated gross benefit (cost) of debt equal to 10.4% (6.9%) of asset value. We find that the cost of being overlevered is asymmetrically higher than the cost of being underlevered and that expected default costs constitute only half of the total ex ante costs of debt.