A dozen or so years ago, a small group of wealthy corporate insurance executives decided their customers were not paying nearly enough for the medical care they received. How else to explain the fact that managed care — which they had touted as a silver bullet just a decade earlier — had failed miserably at controlling health care costs. Those executives came to embrace as the newest silver bullet a strategy incubated at the National Center for Policy Analysis, a Dallas-based libertarian think tank that advocates for fewer government regulations and more individual responsibility.