Regulating retirement savings : An evolutionary psychology approach

Abstract

According to finance theory and supporting evidence, individual investors maximize expected returns on their stock market investments by holding a diversified stock portfolio and by limiting trading. However, a substantial subset of individual investors deviate from this strategy, causing them to earn, on average, a much lower return than if they had followed a diversified strategy. Less wealthy investors and investors who are single men deviate from portfolio theory more than other investors and, consequently, they earn low stock returns. The prevailing view in finance is that individual investors deviate from portfolio theory because of irrational overconfidence and reliance on heuristics. In contrast, the hypothesis of this chapter is that individual investors deviate from portfolio theory and accept lower rates of expected return on investment to try and satisfy other, more pressing, needs. I use evolutionary psychology to show that investors may be deviating from portfolio theory in an effort to attain evolutionarily important goals, such as to acquire status or to acquire a mate.