One result has indeed been immigration -- lots of it. That’s created a problem integrating all the new “guest workers” -- many of them poor Muslims from North Africa or Turkey who form their own insular communities and seem resistant to becoming “Frenchmen” or “Danes” in any cultural sense.

Americans who find themselves rubbing elbows with their own, increasingly Spanish-speaking worker class may empathize. (Note the concern, in this context, is not immigration per se. Rather the question is whether these new waves of immigrants intend to adopt the European or American culture and language of the lands to which they have moved.)

Regardless of that, governments can do the math and figure out what happens when they have fewer young taxpayers to bear the burden of all the fine pensions and other benefits they’ve promised their aging citizenry.

So French Prime Minister Dominique de Villepin last week announced new incentives for Frenchwomen to bear larger families, including a boost in the monthly stipend for parents who take unpaid leave to care for a third child, from the current $622 to between $850 and $1,125.

What’s wrong with this picture?

It may seem presumptuous to give advice to the French on les affaires amoureuses, but what could be more dispiriting, more likely to curb the natural, um ... productive instincts, than a central government that counts your offspring, decides how much time you should get off from work when each one arrives, and even how much you should be compensated on each such occasion, down to the penny?

Will they now keep charts logging each attempt, over at the Palais de l’Elysees, like the breeders of race horses?

If socialism and its high tax rates lead to higher rates of alcoholism and suicide (as they always have, since the “leveling” effects of the doctrine discourage much hope for individual betterment), why should we find it a surprise they also lead to lower birth rates? The more intelligent the animal, the less well it breeds in captivity.

The French government has belatedly made some efforts to curb its outrageous penalties on productivity, dropping the top income tax rate from 57 percent to about 48 percent.But that tax was already producing less revenue than America’s much lower rates, since the French welfare state has long since bankrupted or scared away most top wage earners, anyway.

“Countries trying to collect punitive taxes from the rich, like France and Sweden, end up short of rich people to tax,” wrote Alan Reynolds of the Cato Institute, back in 2002. “As a result, they mainly rely on flat-rate payroll and sales taxes (VAT).” Indeed, the standard national VAT in France is a whopping 19.6 percent -- above and beyond the income tax.

And if that double punch should leave you with more than two centimes to rub together, there’s an additional WEALTH TAX of up to 1.8 percent a year, for simply clinging to more than 720,000 euros in assets.

Here’s a modest proposal: Msr. de Villepin should forget about “stipends,” and eliminate either his income tax, or his VAT. Then take whichever remains, and cut it in half.

Let Frenchmen -- and women -- keep an extra third of what they earn, and he might be amazed at what they can produce ... including more little Frenchmen.