Does Household Finance Matter? Small Financial Errors with Large Social Costs
研究发现，家庭因熟悉性偏好导致投资组合分散不足，每年仅损失约1%的回报，但加上资产配置和消费储蓄决策的扭曲，福利损失扩大四倍，并在一般均衡中进一步放大社会总福利损失。
Households with familiarity biases tilt their portfolios toward a few risky assets. The resulting mean-variance loss from portfolio underdiversification is equivalent to only a modest reduction of about 1 percent per year in a household’s portfolio return. However, once we consider also the effect of familiarity biases on the asset- allocation and intertemporal consumption-savings decisions, the welfare loss is multiplied by a factor of four. In general equilibrium, the suboptimal decisions of households distort also aggregate growth, amplifying further the overall social welfare loss. Our findings demonstrate that financial markets are not a mere sideshow to the real economy and that improving the financial decisions of households can lead to large benefits, not just for individual households, but also for society.