John Stuart Mill believed that the only acceptable reason for government to limit a person's liberty was to prevent him from causing unacceptable harm to others. Mill was not a libertarian, but many libertarians are quick to cite this principle when arguing against a regulation that they oppose. And I believe most thoughtful libertarians are prepared to embrace something fairly close to Mill's harm principle. But accepting that principle implies accepting many of the institutions of the modern welfare state that libertarians have vigorously opposed in the past, such as safety regulation.

No society has ever succeeded without a decent government.

If the search is for examples that contradict the predictions of standard economic models, a good rule of thumb is to start in France.

John Stuart Mill believed that the only acceptable reason for government to limit a person's liberty was to prevent him from causing unacceptable harm to others. Mill was not a libertarian, but many libertarians are quick to cite this principle when arguing against a regulation that they oppose. And I believe most thoughtful libertarians are prepared to embrace something fairly close to Mill's harm principle. But accepting that principle implies accepting many of the institutions of the modern welfare state that libertarians have vigorously opposed in the past, such as safety regulation.

A good school is a relative concept, and the better schools are located in more expensive neighborhoods. But when everyone bids more for a house in a better school district, they succeed only in bidding up the prices of those houses. As before, 50 percent of all children will attend schools in the bottom half of the school quality distribution. As in the familiar stadium metaphor, all stand, hoping to get a better view, only to discover that no one sees better than if all had remained seated.

Many social critics wag their fingers at what they perceive to be frivolous luxury spending. But that misses the point that consumption norms are local. It's not just the rich who spend more when they get more money. Everyone else does, too. The mansions of the rich may seem over the top to people in the middle, but the same could be said of middle-class houses as seen by most of the planet's seven billion people.

Many decry rising inequality because it makes those who've fallen behind feel impoverished. But it's done much more than cause hurt feelings. It has also raised the real cost to middle-income families of achieving many basic goals. The process begins with the completely unremarkable fact that top earners have been spending at a substantially higher rate than before. They've been building bigger mansions, staging more elaborate weddings and coming-of-age parties for their kids, buying more and better of everything.