The Equity Home Bias : Contrasting an Institutional with a Behavioral Explanation

An empirically well-established finding is that equity portfolios are concentrated in the domestic equity market of the investor. Previous theoretical and empirical analyses have mainly focused on institutional explanations and largely neglected individual behavior. In this study we report the results of an experiment in which we contrast institutional with behavioral explanations by comparing asymmetric information to social identity. Our results show that social forces, triggered by group affiliation, drive underdiversified and domestically biased portfolio allocations. Moreover, social identity explains the observed behavior equally well as asymmetric information. We also find that individuals are spuriously more optimistic toward the performance of domestic firms