Whereas standard models of portfolio choice indicate that most households should have equity market exposure, only one-third of . households own stocks or stock mutual funds outside of retirement plans, and only one-half participate in the stock market even when retirement plans are included into the calculation. 2 There are numerous reasons to suspect that one’s decision about whether or not to invest in stocks may be inf luenced by the stock market participation of one’s community by means of social interaction. Hong, Kubik, and Stein (2004) present a formal model and discuss several possible path- ways for this effect. For example, social interaction may serve as a mechanism for.
