France and California – what a pair.

France’s economy is bigger than California’s, though not by much. The number of its protestors may be larger too: Tuesday three million protestors hit the streets in France, whereas the students and workers on the streets in Los Angeles on Saturday numbered 500,000 or so.

But there are more enduring differences. In Paris students are marching against a law that makes it easier for employers to fire them. They don’t care if that same law makes it easier to hire someone else. “Don’t touch my job,” the protestors are saying, in essence. The emphasis is on the “my.”

The LA students are marching on behalf of illegal immigrants, whom they don’t want to see criminalized. The LA protest also contains an implicit message about jobs, the opposite of the French one. “Welcome those immigrants. I’m not worried about my job, or security. I’m willing to share.”

Watching all this you might conclude that California students are nicer than the French ones – less selfish, more generous. It’s a striking difference. California after all is supposed to be the state where it’s all about me. French youth are famous for their idealism.

But what causes the difference? The answer has nothing to do with the influence of television, or the protestors’ religion, or their individual biochemical profiles. It has rather to do with the economic growth that the children of developed nations view as their birthright. Growth forgives, and it makes people more forgiving. Especially when they expect more growth in the future.

Adam Smith, the philosopher, wrote that in a growing economy, “the great body of the people seem to be the happiest and the most comfortable.” Life was, Smith noted, by contrast, “hard in the stationary, and miserable in the declining state.” Baron de Montesquieu, one of Smith’s French counterparts, wrote of a related phenomenon: “everywhere there is commerce, there are gentle mores.”

There’s something in us that balks at talking about economics and virtue in the same breath. But several centuries after he put it down, Montesquieu’s thesis is proving itself anew in his homeland. After World War II, France seemed to grow just fine. Real per capita income rose. In 1973, unemployment was less than 3 percent in France, well below the 5 percent in the U.S.

All that growth and employment put France, and Germany for that matter, in a sharing mood. People born in the 1960s, and 1970s had the impression that France would grow forever. Back in 1985, France hosted one of the friendlier and most pro-immigrant events in the history of the world, a concert for hundreds of thousands whose theme was opposing racism. The motto that year was “Touche Pas a Mon Pote” – “Don’t touch my buddy,” the immigrant. Gentler mores would have been hard to find.

But then France became “stationary,” to use Smith’s term. As the government grew, and competition from developing nations increased, growth slowed. Unemployment began to range consistently higher than that in the U.S. Youth unemployment moved into the 20-percent range. By 2000, almost half of all unemployed Frenchmen had been out of work for more than a year.

In a statement more terrifying than any made by students, the Archbishop of Paris last week told demonstrators that “honestly I do not believe that anybody can guarantee you this security, no more than guarantee that you will have a standard of living comparable to your parents.” Small wonder the French students are not in a sharing mood. The archbishop is telling them that growth isn’t their birthright, after all.

The California experience is the opposite: citizens of the Golden State, including Hispanics, are increasingly confident that growth is indeed their birthright. California unemployment came within a hair of 10 percent in the early 1990s, a period when anti-immigrant nastiness increased as well. Since the mid-1990s, despite whatever spending lawmakers in Sacramento did, unemployment has gone down; in February it was 5 percent.

The state Department of Finance shows California’s per capita income rising every year since 1988 – and always exceeding the U.S. average. For as long as teenagers can remember, there has been growth and there have been jobs. They don’t merely feel entitled to entitlements. They also feel entitled to growth, which is different.

It’s easy to quibble with this analysis. In the economics crowd some will argue that globalization, not flawed policy, is what is hurting France. The foreign-policy crowd will argue that an angry North African population is inherently different from California’s Hispanics.

But the crowds in France keep taking to the street. And their demonstrations remind us that growth has effects in other areas of our lives, including politics. U.S. Republicans, for example, have found numerous times that anti-immigrant nativism backfires; people are doing too well to see the appeal.

In an enlightening new book, “The Moral Consequences of Economic Growth,” Benjamin Friedman, a Harvard University economist, posits that morality and growth are related: “Economic growth not only relies upon moral impetus, it also has positive moral consequences.”

It’s all worth considering as smoke from burning cars wafts around the Eiffel Tower. In the end the French troubles reveal not the selfishness of the students, but that of their parents and Mother France. They are the ones, after all, who hurt their own children rather than harm the large French state.

Miss Shlaes is a columnist for Bloomberg News.