[We develop a model with incomplete markets and heterogeneous agents that generates a large equity premium, while simultaneously matching stock market participation and individual asset holdings. The high risk-premium is driven by incomplete risk sharing among stockholders, which results from the combination of aggregate uncertainty, borrowing constraints, and a (realistically) calibrated life-cycle earnings profile subject to idiosyncratic shocks. We show that it is challenging to simultaneously match asset pricing moments and individual portfolio decisions, while limited participation has a negligible impact on the risk-premium, contrary to the results of models where it is imposed exogenously.]

[We study the simultaneous impact of fiscal policy decisions on macroeconomic activity, wealth distribution, and asset prices. We consider a general equilibrium, overlapping generations model with incomplete markets and heterogeneous agents, where government debt and capital are imperfect substitutes. Increases in public debt lead to significant increases in the riskless rate and to a reduction in the equity premium, while higher capital income tax rates lead to a higher equity premium. The crowding-out effects (on capital and output) are much higher than in models where government debt and capital are perfect substitutes, which thus ignore households' portfolio reallocation decisions.]

[Using microeconomic data for the United Kingdom, we analyze the empirical determinants of voluntary annuity market demand. We find that annuity market participation increases with financial wealth, life expectancy, and education and decreases with other pension income and a possible bequest motive for surviving spouses. We then show that these empirically motivated determinants of annuity market participation have the same, quantitatively important, effects in a life-cycle model of annuity and life insurance demand, saving, and portfolio choice. Moreover, reasonable preference parameters predict annuity demand levels comparable to the data. For stockholders, a strong bequest motive can simultaneously generate balanced portfolios and low annuity demand.]

We solve for optimal consumption and portfolio choice in a life-cycle model with short-sales and borrowing constraints; undiversifiable labor income risk; and a predictable, time-varying, equity premium and show that the investor pursues aggressive market timing strategies. Importantly, in the presence of stock market predictability, the model suggests that the conventional financial advice of reducing stock market exposure as retirement approaches is correct on average, but ignoring changing market information can lead to substantial welfare losses. Therefore, enhanced target-date funds (ETDFs) that condition on expected equity premia increase welfare relative to target-date funds (TDFs). Out-of-sample analysis supports these conclusions.

1 We solve a model with incomplete markets and heterogeneous agents that generates a large equity premium, while simultaneously matching stock market participation and indi-vidual asset holdings. The high risk premium is driven by incomplete risk sharing among stockholders, which results from the combination of aggregate uncertainty, borrowing con-straints and a (realistically) calibrated life-cycle earnings profile subject to idiosyncratic shocks. We show that it is challenging to simultaneously match asset pricing moments and individual portfolio decisions, while limited participation has a negligible impact on the risk premium, contrary to the results of models where it is imposed exogenously. JEL Classification: G11, G12.

We study quantitatively how uncertainty in expected stock return predictability affects life-cycle portfolio choice and wealth accumulation in the presence of undiversifiable labor income risk. Households filter information about future expected returns from observed predictors and realized stock returns. Therefore, optimal portfolio choice does not only depend on financial wealth and age, as in more traditional life-cycle models. Counterfactuals demonstrate the magnitude of portfolio demand changes that depend on perceptions about underlying expected returns. On average, life-cycle asset allocation becomes more conservative than models with either i.i.d. stock returns, or with clearer signals about expected stock returns.

Using a calibrated, collective life-cycle portfolio choice model for a dual-income couple, we show that an increase in the ability to share risk within the household due to a mean-preserving spread in the partners’ coefficients of relative risk aversion leads to a substantial increase in financial risk-taking. Importantly, we show that risk sharing has a larger economic impact on portfolio choice than risk diversification. While unitary models usually do not fully replicate the optimal portfolio choice of collective models, we propose approximations that work reasonably well for moderate background risk. We provide strong empirical support for our key findings.

We study the simultaneous impact of fiscal policy decisions on macroeconomic activity, wealth distribution, and asset prices. We consider a general equilibrium, overlapping generations model with incomplete markets and heterogeneous agents, where government debt and capital are imperfect substitutes. Increases in public debt lead to significant increases in the riskless rate and to a reduction in the equity premium, while higher capital income tax rates lead to a higher equity premium. The crowding-out effects (on capital and output) are much higher than in models where government debt and capital are perfect substitutes, which thus ignore households' portfolio reallocation decisions. The Author 2012. Published by Oxford University Press on behalf of The Society for Financial Studies. All rights reserved. For Permissions, please e-mail: [email protected]., Oxford University Press.

We show that a life-cycle model with realistically calibrated uninsurable labor income risk and moderate risk aversion can simultaneously match stock market participation rates and asset allocation decisions conditional on participation. The key ingredients of the model are Epstein–Zin preferences, a fixed stock market entry cost, and moderate heterogeneity in risk aversion. Households with low risk aversion smooth earnings shocks with a small buffer stock of assets, and consequently most of them (optimally) never invest in equities. Therefore, the marginal stockholders are (endogenously) more risk averse, and as a result they do not invest their portfolios fully in stocks.

Does Buffer-Stock Saving Explain the Smoothness and Excess Sensitivity of Consumption? by Sydney C. Ludvigson and Alexander Michaelides. Published in volume 91, issue 3, pages 631-647 of American Economic Review, June 2001