9De Nardi (2015), section 4 discusses mechanisms to generate realistic wealth heterogeneity, also focusing on various forms of preference heterogeneity. Discount factor heterogeneity seems to be the most widespread, although other mechanisms were also proposed, e.g., preference for bequests, habit formation or “capitalist spirit.” Discount factor heterogeneity seems to be a more powerful mechanism than e.g., heterogeneity in risk aversion. A new paper by Cozzi (2012) shows it is also possible to match the wealth distribution with heterogeneity in the CRRA coefficient ρ  . However, the lognormal distribution he assumes for ρ  imposes that some households have a very high risk aversion and his calibration of β ≈ 0.88  is very low.