For at least the last six decades optimal portfolio selection has been one of the main focuses of financial research. Since Markowitz (1952) many authors have developed ideas about the optimal allocation of assets that have reached today's mainstream portfolio decision-making. However, many of them miss the single largest investment most people make in their lifetime, their home. Therefore, this research seeks to analyze the impact of the owner-occupied home on the portfolio in order to determine its optimal allocation. The motivation for this analysis is derived from the individual investor who spends a lifetime saving in order to maximize their long-term wealth. The advantage of this study over previous research is the use of directly available assets through the use of Vanguard Funds. By using this dataset, three goals are achieved: (1) investing over the largest set of asset classes included in the research to date, (2) minimizing the cost of investing for the portfolio owner, and (3) providing a source of investable assets that are available to the small investor.
The results have a substantial impact on the wealth accumulation of owner-occupier investors. First, the results show that including unleveraged owner-occupied housing in the portfolio is beneficial only at low levels of portfolio risk. Second, the results show that including leveraged owner-occupied housing in the portfolio is beneficial across all levels of portfolio risk. At low levels of portfolio risk all of the MSAs have some allocation to leveraged owner-occupied housing, however this allocation changes as the Loan-to-Value (LTV) Ratio increases. However, regardless of the LTV ratio, risk reduction at the lowest portfolio risk level is visible, but less so as the LTV ratio increases. Third, investors looking to allocate their investable funds across their portfolio without adding the mortgage will be over-investing in leveraged housing and potentially taking on too much unsystematic risk for the level of return received. Fourth, higher tax bracket investors have greater allocation to leveraged owner-occupied housing than lower tax bracket investors and achieve higher rates of return in comparison to the same Tax Bracket Renter Portfolio.