Home Bias in International Stock Return Expectations

Despite the advantages of international portfolio diversification, actual equity portfolio holdings reveal a strong bias towards domestic stocks. One hypothesis is that this bias can be explained by stock return expectations expressed in probability judgments. To test that hypothesis and to analyze the underlying effects that might cause distortions in investors' expectations, we conducted a cross country study in Germany and the U.S. comparing participants' judgments about an identical set of German and U.S. stocks.

Results show that both test groups feel more competent about domestic stocks. The asymmetric perception of competence is connected with an asymmetric assessment of probabilities. For both test groups subjective probability distributions of stock returns are significantly less dispersed and more optimistic for stocks associated with high competence levels than for stocks associated with low competence levels.