Optimists work harder and plan to keep working longer, according to Duke University finance professors Manju Puri and David Robinson. The most extreme optimists went the other way: they worked fewer hours and saved less money. Each person's guess about how long they would live became the optimism score. Puri and Robinson took answers from the Federal Reserve's Survey of Consumer Finances and compared them with official life expectancy tables, so people who expected to outlive the statistics counted as optimists. The score lined up with standard psychology tests of optimism and with people's hopes for the economy. The study appeared in the Journal of Financial Economics in 2007. Optimists worked more hours each week and expected to retire later. They saved more, put more money into individual stocks, and were more likely to remarry after a divorce. Self-employed people scored as more optimistic than regular employees. Extreme optimists, the people who expected to live far longer than the tables predicted, looked different. They worked fewer hours, saved less, were less likely to pay off their credit cards regularly, and were more likely to smoke. Survey data like this can't show which comes first, since hard work and savings might also make people feel more hopeful. Across American households, a moderate overestimate of your future went with working harder and planning ahead, and a wildly inflated one went with the opposite.