Role of Real Estate in a Mixed-Asset Portfolio and the Impact of Illiquidity

Real estate ratios have increased in recent years. This article thus examines the diversification potential of real estate investments that German investors can achieve at a global scale. To this end, it analyzes how the illiquidity of some real estate investments or the illiquidity preference of an investor can bring about optimal investment ratios. Optimum allocation quotas for German investors with a wide range of mixed-asset allocations are examined. In addition to traditional optimizations, this article applies the three-fund theorem to include liquid and illiquid forms of real estate investment and to determine optimum allocation ratios. While real estate may be an essential component in a mixed-asset portfolio, it is not included in all optimal portfolios. An optimal portfolio also depends on the investment form, insofar as real estate vehicles are not always suitable for diversifying the portfolio risk or for improving the performance of a mixed-asset portfolio. Moreover, illiquid investment vehicles can often provide strong diversification benefits. The optimum allocations to real estate thus depend on the investor’s illiquidity acceptance, even if allocation dominance has increased in recent years. While many studies have demonstrated the advantage that investors gain from adding certain real estate assets, such as those obtained by direct investments, this study goes further by examining the comparative advantage of different real estate investment forms within a variety of asset classes. New insights can thus be gained by considering investors’ liquidity preferences within a given portfolio. One of these insights is that there is a trade-off between illiquidity and diversification potential. Another is that optimum portfolio allocations depend on illiquidity acceptance. These findings therefore also provide practical guidance not only to German investors with a global portfolio diversification but also to practitioners who add illiquid asset classes to their portfolio, to say nothing of the valuable field knowledge it offers to researchers in this field.