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.

This paper estimates the cross‐sectional distribution of Epstein‐Zin preferences using the wealth and risky portfolio shares of a large panel of Swedish households. We find modestly heterogeneous risk aversion (standard deviation 0.97, median 7.50) and a meaningfully heterogeneous and right‐skewed time preference rate (TPR; standard deviation 7.31%, median 4.08%) and elasticity of intertemporal substitution (EIS; standard deviation 3.17, median 0.70). Risk aversion and the EIS are only very weakly negatively correlated. We estimate lower risk aversion for households with riskier labor income, and a higher TPR and lower EIS for households that enter our sample with low wealth.

We show that incorporating defined benefit pension funds in an incomplete markets asset pricing model improves its ability to match the historical equity premium and riskless rate and has important risk‐sharing implications. We document the importance of the pension fund's size and asset demands, and a new risk channel arising from fluctuations in the fund's returns. We use our calibrated model to study the implications of a shift to an economy with defined contribution plans. The new steady state is characterized by a higher riskless rate and a lower equity premium. Consumption volatility increases for retirees but decreases for workers.