They’re not ready to talk about all their ideas, but I think there are two big ways that libertarian paternalism can work its magic. The first has to do with bureaucracy. No matter how lofty the aims of a government program, it usually won’t make a difference if people can’t understand it.

Five years ago, the Charlotte-Mecklenburg Schools, the largest district in North Carolina, started a school choice program, giving parents a bigger say over where their children went to school. But finding good information about schools, like their average test scores, sometimes seemed like an unpleasant exam in its own right. Parents often had to wade through a Web site filled with acronyms like EOC, EOG, ABC and AYP.

Last year, at the urging of an economist named Justine Hastings and two other Yale researchers, the Charlotte schools conducted a little experiment to see if this complexity mattered. Along with their school choice applications, a few thousand parents were also mailed a sheet of paper listing a single test score — the average of the math and reading scores — for each school they could apply to.

And guess what? These parents were much more likely than others to apply to schools with high scores. They were starting to create the feedback loop that is the whole point of school choice.

Unfortunately, Charlotte hasn’t drawn the obvious lesson from the experiment and continues to make good information hard to find. This same sort of complexity has plagued Medicare Part D, the new prescription drug benefit. Almost one-quarter of low-income people eligible for a subsidy aren’t getting it because they have not signed up for the program at all. “It’s sufficiently complicated that people sort of throw up their hands and say, ‘I can’t deal with it,’ ” said Joseph Newhouse, a Harvard economist.

Likewise, there are almost seven million children without health insurance who are eligible for the State Children’s Health Insurance Program but are not in it. A few proposals to make it easier for children to be signed up are now working their way through Congress. In every one of these cases — school choice, Medicare, health insurance — the government can help people make good choices by tearing down bureaucratic hurdles.

The second big nudging strategy puts up hurdles — in front of bad choices that are otherwise easy to make. This is what Dr. Gropper did in his intensive care unit. Other hospitals have undertaken similar efforts in the last decade, and as a result, the national pneumonia rate has fallen.