At the Democratic National Convention last year, actress Eva Longoria called for higher taxes on America's rich. Her take: "The Eva Longoria who worked at Wendy's flipping burgers—she needed a tax break. But the Eva Longoria who works on movie sets does not."

Actually, nowadays an Eva Longoria who flipped burgers would probably qualify for the Earned Income Tax Credit and get a check from the government rather than pay taxes. It's the movie set where she works these days that may well be getting the tax break.

With campaign season over, you're not likely to hear stars bringing up taxes at this weekend's Academy Awards show. But the tax man ought to come out and take a bow anyway. Of the nine "Best Picture" nominees in 2012, for example, five were filmed on location in states where the production company received financial incentives, including "The Help" (in Mississippi) and "Moneyball" (in California). Virginia gave $3.5 million to this year's Oscar-nominated "Lincoln."

Such state incentives are widespread, and often substantial, but they don't do much to attract jobs. About $1.5 billion in tax credits and exemptions, grants, waived fees and other financial inducements went to the film industry in 2010, according to data analyzed by the Center on Budget and Policy Priorities. Politicians like to offer this largess because they get photo-ops with celebrities, but the economic payoff is minuscule. George Mason University's Adam Thierer has called this "a growing cronyism fiasco" and noted that the number of states involved skyrocketed to 45 in 2009 from five in 2002.

In its 2012 study "State Film Studies: Not Much Bang For Too Many Bucks," the Center on Budget and Policy Priorities found that film-related jobs tend to go to out-of-staters who jet in, then leave. "The revenue generated by economic activity induced by film subsidies," the study notes, "falls far short of the subsidies' direct costs to the state. To balance its budget, the state must therefore cut spending or raise revenues elsewhere, dampening the subsidies' positive economic impact."