Women are obviously less willing to take investment risks than men, right?
A seminal study by professors Brad Barber and Terrance Odean famously found that men trade more aggressively than women within brokerage accounts. Other early studies found that women prefer safer portfolios in their defined contribution plans. The perception of the fairer sex as less willing to suffer the cruel volatility of a stock-laden portfolio fits well with common beliefs about the differences between men and women.
But there's more to this story. Women and men are different, but not just biologically different. Women in older cohorts were less likely to go to college, many interrupted their working lives to raise children, and others chose not to assume responsibility for managing household investments. It's important to understand why these differences exist because an overly conservative portfolio can be just as inappropriate as an overly risky one.
Risky Reluctance
How harmful are risk-averse portfolios? Federal Reserve Bank economist Urvi Neelakantan estimates that the more conservative retirement investments of women can explain about 10% of the gender difference observed in sheltered retirement account balances. Since women live longer than men on average, they will need more money to fund the same level of retirement income. Maintaining some risk in a retirement portfolio is especially important given stocks' more favorable risk/return characteristics when held for a long period of time. Gender differences in risk tolerance can have important social implications if women are less prepared for retirement than men.
If women are less willing to take risks than men because they are wired differently, then this difference should show up in other decisions that involve taking chances. The evidence is mixed. Perhaps no scholar has spent more time studying the question than Stockholm School of Economics professor Anna Dreber. She finds no difference in risk taking between male and female professional bridge players, but these same players exhibited differences in financial risk aversion on a questionnaire. She also finds few differences in competitiveness between school-age girls and boys in various tasks.
Ohio State professor Sherman Hanna has studied gender differences in the Federal Reserve's Survey of Consumer Finances and finds more evidence that women and men may not be that different. Hanna compared portfolio allocation and responses to risk tolerance questions among same-sex couples and opposite-sex married couples. Married (opposite sex) women who responded to the survey were indeed less willing to take financial risks than men. But women within a same-sex couple were just as willing to take financial risk as married men. In fact, women in a same-sex couple were slightly more willing to take investment risks than men in a same-sex couple. This throws a wrench in the biology theory.
Hanna's most interesting finding may be that while women in same-sex couples are more willing to take financial risks, they actually hold less stock in their portfolios than married heterosexual couples. In the article, Hanna and his co-author Suzanne Lindamood wonder whether these less risky portfolios may reflect a bias on the part of financial service providers who assume that women aren't as interested in a risky portfolio.
This is one of the dangers of placing too much weight on an early piece of research that fits our own preconceived ideas. We tend to be much more receptive to information that is consistent with what we already believe, also known as the confirmation bias. The popularity of the Barber and Odean study may have been enhanced by how well it fit conventional wisdom about gender differences—it was even titled "Boys will be boys."
Digging Deeper
La Salle University professor Michael Roszkowski and University of Georgia professor John Grable find that the intuition of financial advisors about gender differences isn't very accurate. The correlation between the advisor estimate of risk tolerance and actual risk tolerance (measured using a common risk tolerance assessment tool) was only 0.41. The reason advisors were not able to consistently assess the risk tolerance of their clients was that they overestimated the risk tolerance of male clients and underestimated the risk tolerance of female clients. This bad intuition is a problem that can lead to making the wrong portfolio recommendations.
According to Texas Tech professor (and neuroscience expert) Russell James, most of us prefer relying on stereotypes because they save us time and effort. It takes less time to make assumptions than it does to dig a little deeper. "Bottom line, knowing about differences in the average behavior of men and women tells you absolutely nothing about the client sitting in front of you," notes James. "It is easy to think of yourself as being scientific by using a rule of thumb based on population averages, but it's really just being lazy. Don't assume."