Systematic Risk and Diversification in the Equity REIT Market

This paper employs stock market-based data to examine the systematic risk and diversification properties of publicly traded equity real estate investment trusts (REITs). A unique data sample is created by combining firm return data with information on their property type holdings and the location of their investments. A number of interesting findings arise from this work: (1) the systematic risk of equity REITs appears to vary by the type of property in which they invest, with beta being significantly higher for retail-oriented REITs than for REITs owning industrial and warehouse properties; (2) the stock market data provide no evidence that REIT diversification across property types or broad geographic regions actually results in meaningful diversification across property types or broad geographic regions actually results in meaningful diversification as reflected in a standard market-based measure -- the R2 from a simple market model regression; and (3) a very simple measure of diversification, the number of properties owned by the REIT, is positively correlated with the R2 from a simple market model regression; a REIT’s stock return variance of total return also is systematically lower the greater the number of properties owned by the firm.