Household portfolio choices under (non-)linear income risk: an empirical framework

This paper develops a flexible, semi-structural framework to empirically quantify the non-linear transmission of income shocks to household portfolio choice decisions both at the extensive and intensive margins. I model stock market participation and portfolio allocation rules as age-dependent functions of persistent and transitory earnings components, wealth and unobserved taste shifters. I establish non-parametric identification and propose a tractable, simulation-based estimation algorithm, building on recent developments in the sample selection literature. Using recent waves of PSID data, I find heterogeneous income and wealth effects on both extensive and intensive margins, over the wealth and life-cycle dimensions. These results suggest that preferences are heterogeneous across the wealth distribution and over the life cycle. Moreover, in impulse response exercises, I find sizeable extensive margin responses to persistent income shocks. Finally, I find heterogeneity in participation costs across households in the wealth distribution.