Home-country bias is the tendency of an investor to over-invest in his/her country’s domestic equity market in a scale that significantly exceeds the proportion of the size of the domestic market relative to the rest of the world.

Considering that even Americans, whose own stock market is 40% to 50% of the world market, can be guilty of home-country bias, it is not a surprise that investors from much smaller markets like the Philippines also exhibit this behavior. This is shown in the chart below, which visualizes data collected by Sercu and Vanpée from CPIS (December 2005) and World Federation of Exchanges, in their paper, Home bias in international equity portfolios: a review. When that paper was published, Filipinos’ equity portfolios were 99.5% domestic while the domestic market was just 0.1% of the world market cap.