"Answer me this: would you work harder to earn $100 or avoid losing $100? The smiley optimist says the former, but if research from the Center for Experimental Social Science at New York University is any indication, fear of loss is the home-run winner. Experimental groups given $15 and then told the $15 would be rescinded if they lost a subsequent auction routinely overbid the most. Groups offered $15 if they won weren't nearly as "committed."