Home bias
What is Home bias?
Home bias is allocating more to domestic assets than their weight in the investable global opportunity set would imply.
Country exposure should be measured through underlying revenue, assets, currency, and risk, not listing venue alone. A domestic index can contain multinational businesses, while a foreign fund can still depend on the investor's home economy. Look-through analysis prevents a simple country label from overstating or understating diversification.
The appropriate comparison should also reflect the investor's human capital, property, pension, future spending currency, tax, access, and ability to tolerate foreign-market uncertainty through difficult global financial market cycles.
Why it occurs
Domestic assets feel familiar, use the spending currency, receive more media coverage, and can be easier or cheaper to access. Regulation, tax, liabilities, governance, and information advantages can also justify some domestic tilt. Bias describes concentration beyond what objectives and constraints support, not every departure from global market capitalization.
Portfolio consequences
A home-heavy portfolio concentrates country, policy, sector, currency, and economic risk. Domestic employment, property, pension, and business income can increase the same exposure. Some markets are dominated by a few industries or firms. International diversification can broaden opportunities, but introduces foreign-exchange, withholding, custody, political, and governance risks.
Example
An investor earns salary, owns property, and holds nearly all equities in one small domestic market. A local recession could weaken income, property, and portfolio together. Adding global assets can reduce that joint dependency even if foreign holdings appear individually less familiar and create visible currency movement.
Measurement
Compare allocation with a chosen global benchmark and look through funds by country, revenue, currency, sector, and risk. Listing location is incomplete because multinationals earn abroad and foreign companies may depend on domestic demand. Include nonportfolio wealth and liabilities when judging the appropriate tilt. Market-cap weight is a reference, not a mandatory optimum.
Practical controls
Set a documented domestic range reflecting spending currency, tax, access, liability matching, and diversification. Use low-cost global vehicles where suitable and rebalance. Assess withholding, fund domicile, currency hedging, and geopolitical constraints. Avoid replacing home bias with unexamined concentration in one foreign market or assuming international assets always reduce short-term volatility.
Sources and further reading
- Investor Diversification and International Equity Markets, American Economic Review
- Ten Things to Consider Before You Make Investing Decisions, Investor.gov, U.S. Securities and Exchange Commission