A frictionless general equilibrium model featuring heterogeneous time-varying risk tolerance explains the business cycle dynamics of intermediary leverage, aggregate credit, and other asset markets’ facts. In booms, when risk tolerance is high, households borrow more and aggregate credit increases funded by higher intermediary debt. In recessions, credit contracts and intermediaries delever. Yet, their debt-to-equity ratios increase as equity drops when risk aversion increases. Because households borrow more or less as their risk tolerance increases or decreases, the intermediary’s balance sheet forecasts stock returns both in the time series and the cross section. Moreover, credit expansions correlate with negatively skewed stock returns, low credit spreads, and predict lower future returns.

Non-linear external habit persistence models, which feature prominently in the recent “equity premium” asset pricing and macroeconomics literature, generate counterfactual predictions in the cross-section of stock returns. In particular, we show that in the absence of cross-sectional heterogeneity in firms’ cash-flow risk, these models produce a “growth premium,” that is, stocks with high price-to-fundamental ratios command a higher premium than stocks with low price-to-fundamental ratios. This implication is at odds with the well-established empirical observation of a “value premium” in the cross-section of stock returns. Substantial heterogeneity in firms’ cash-flow risk yields both a value premium as well as most of the stylized facts about the cross-section of stock returns, but it generates a “cash-flow risk puzzle”: Quantitatively, value stocks have to have “too much” cash-flow risk compared to the data to generate empirically plausible value premiums.

We propose a novel economic mechanism that generates stock return predictability in both the time series and the cross-section. Investors' income has two sources, wages and dividends that grow stochastically over time. As a consequence the fraction of total income produced by wages fluctuates depending on economic conditions. We show that the risk premium that investors require to hold stocks varies with these fluctuations. A regression of stock returns on lagged values of the labor income to consumption ratio produces statistically significant coefficients and large adjusted R2s. Tests of the model's cross-sectional predictions on the set of 25 Fama-French portfolios sorted on size and book-to-market are also met with considerable support.

We propose a novel economic mechanism that generates stock return predictability in both the time series and the cross-section. Investors’ income has two sources, wages and dividends that grow stochastically over time. As a consequence the fraction of total income produced by wages fluctuates depending on economic conditions. We show that the risk premium that investors require to hold stocks varies with these fluctuations. A regression of stock returns on lagged values of the labor income to consumption ratio produces statistically significant coefficients and large adjusted R2s. Tests of the model’s cross-sectional predictions on the set of 25 Fama–French portfolios sorted on size and book-to-market are also met with considerable support.

This paper studies the matching of opportunities with talent when costly diagnosis confers an informational advantage to the agent undertaking it. When this agent is underqualified, adverse selection prevents efficient referrals through fixed-price contracts. Spot-market contracts that rely on income sharing can match opportunities with talent but induce a team-production problem which, if severe enough, can prevent the referral of valuable opportunities. Partnership contracts, in which agents agree in advance to the allocation of opportunities and of the revenues they generate, support referrals where the market cannot, but often at the expense of distortions on those opportunities that are not referred.

We consider organizations that optimally choose the level of adaptation to a changing environment when coordination among specialized tasks is a concern. Adaptive organizations provide employees with flexibility to tailor their tasks to local information. Coordination is maintained by limiting specialization and improving communication. Alternatively, by letting employees stick to some preagreed action plan, organizations can ensure coordination without communication, regardless of the extent of specialization. Among other things, our theory shows how extensive specialization results in organizations that ignore local knowledge, and it explains why improvements in communication technology may reduce specialization by pushing organizations to become more adaptive.

Futures exchanges and other financial intermediaries assume counterparty risks and demand in return guarantees that these counterparties will deliver on their promises. It is often argued that to attract volume, financial intermediaries would settle for excessively low contractual guarantees. In Tano Santos and José Scheinkman (2001) we model financial intermediation in an environment where traders may choose to default, and we examine the characteristics of the equilibrium. In particular, we investigate whether competition implies excessively low standards. We show that in fact, when society punishes default and intermediaries can impose collateral requirements to effectively limit the size of positions, competition leads to a (constrained) optimal amount of contractual guarantees. In Santos and Scheinkman (2001) we assume that exchanges cannot control the size of the positions taken by individuals, but we preclude investors from participating in more than one exchange. This ignores the effect that trading with one financial intermediary may have on the risks faced by other intermediaries. Financial intermediaries typically cannot control the amount of risk that counterparties will take with other intermediaries. In this paper we examine the effect of dropping this exclusivity assumption. We show that the constrained optimum can no longer be implemented as a standard Nash equilibrium with free entry. Nonetheless this allocation is the only one that can be sustained as an anticipatory equilibrium (Charles Wilson (1977)). To break a candidate anticipatory

We propose a general equilibrium model with multiple securities in which investors' risk preferences and expectations of dividend growth are time-varying. While time-varying risk preferences induce the standard positive relation between the dividend yield and expected returns, time-varying expected dividend growth induces a negative relation between them. These offsetting effects reduce the ability of the dividend yield to forecast returns and eliminate its ability to forecast dividend growth, as observed in the data. The model links the predictability of returns to that of dividend growth, suggesting specific changes to standard linear predictive regressions for both. The model's predictions are confirmed empirically.

A common practice in the finance literature is to create characteristic portfolios by sorting on characteristics associated with average returns. We show that the resultant portfolios are likely to capture not only the priced risk associated with the characteristic but also unpriced risk. We develop a procedure to remove this unpriced risk using covariance information estimated from past returns. We apply our methodology to the five Fama-French characteristic portfolios. The squared Sharpe ratio of the optimal combination of the resultant characteristic-efficient portfolios is 2.13, compared with 1.17 for the original characteristic portfolios.

We propose an incentive-based theory of how a savings glut produces financial fragility. Originators must be incentivized to produce high-quality assets. Assets are distributed to informed intermediaries or uninformed investors. A savings glut reduces origination incentives by compressing spreads between the prices paid for high-quality assets by informed intermediaries and prices paid by uninformed investors for generic assets. The narrowing of spreads relaxes intermediaries’ borrowing constraints, resulting in higher leverage. This generates financial fragility: intermediaries are more likely to become insolvent if unforeseen losses arise. Our model offers a coherent narrative of the run-up to the Global Financial Crisis.