We propose a new framework for pricing assets, derived in part from the traditional consumption-based approach, but which also incorporates two long-standing ideas in psychology: prospect theory, and evidence on how prior outcomes affect risky choice. Consistent with prospect theory, the investor in our model derives utility not only from consumption levels but also from changes in the value of his financial wealth. He is much more sensitive to reductions in wealth than to increases, the ``loss-aversion'' feature of prospect utility. Moreover, consistent with experimental evidence, the utility he receives from gains and losses in wealth depends on his prior investment outcomes; prior gains cushion subsequent losses-the socalled "house-money'' effect-while prior losses intensify the pain of subsequent shortfalls. We study asset prices in the presence of agents with preferences of this type, and find that our model reproduces the high mean, volatility, and predictability of stock returns. The key to our results is that the agent's risk-aversion changes over time as a function of his investment performance. This makes prices much more volatile than underlying dividends and together with the investor's lossaversion, leads to large equity premia. Our results obtain with reasonable values for all parameters.

We propose a new framework for pricing assets, derived in part from the traditional consumption-based approach, but which also incorporates two long-standing ideas in psychology: prospect theory, and evidence on how prior outcomes affect risky choice. Consistent with prospect theory, the investor in our model derives utility not only from consumption levels but also from changes in the value of his financial wealth. He is much more sensitive to reductions in wealth than to increases, the ``loss-aversion'' feature of prospect utility. Moreover, consistent with experimental evidence, the utility he receives from gains and losses in wealth depends on his prior investment outcomes; prior gains cushion subsequent losses-the socalled "house-money'' effect-while prior losses intensify the pain of subsequent shortfalls. We study asset prices in the presence of agents with preferences of this type, and find that our model reproduces the high mean, volatility, and predictability of stock returns. The key to our results is that the agent's risk-aversion changes over time as a function of his investment performance. This makes prices much more volatile than underlying dividends and together with the investor's lossaversion, leads to large equity premia. Our results obtain with reasonable values for all parameters.

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 o¤setting e¤ects 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 speci…c changes to standard linear predictive regressions for both. The model's predictions are con…rmed empirically.

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.

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