No one could argue with a straight face that the couples getting married today are much happier just because their wedding celebrations cost three times as much as those in 1980. Bigger mansions and costlier parties are wasteful in the same sense that larger antlers on all bull elk are wasteful. The good news is that simple changes in the tax system can eliminate much of this waste without having to deny people the right to decide for themselves how best to spend their money.

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.

Unless we can act collectively, there would be no way to defend ourselves, no way to define or enforce property rights. We couldn't curb congestion or pollution or build and maintain public infrastructure.

The link between rational individual behavior and collectively desirable outcomes is extremely tenuous.

Economics, as it is often taught today, portrays us as homo economicus-someone who doesn't vote in presidential elections, doesn't return lost wallets, and doesn't leave tips when dining out of town. Julie Nelson reminds us that most people aren't really like that. She helps point the way to a richer, more descriptive way of thinking about economic life.

No society has ever succeeded without a decent government.

As economists have long noted, the puzzle is not that so few people vote, it's that so many do. After all, no individual's vote has ever tipped the balance in a presidential election.