Cross-posted from New Deal 2.0.

In the debate over work-life balance, there's one argument we can't seem to move past: Women have made a choice to have kids. Now they have to live with their decision and all of its consequences.

But this argument rests on an underlying assumption that, when challenged, just doesn't hold up. If faced with a stark choice between work and family, the Jack Welches of the world seem to think women are going to choose family, while men are going to choose work. Otherwise the idea of a workforce that doesn't need time off for childbearing doesn't make sense. Kids need to come from somewhere. It follows, therefore, that the expectation is that women will "opt out" to raise families rather than pursue a career. (We're not even going to talk about the opt-out debate in this post, as Joan's been over that already.)

But what happens if women don't choose family? What happens if they choose career? The cover story in this week's Economist illustrates what happens when women are given a stark choice between having children and a having a successful career. It turns out -- surprise! -- that a lot of them don't choose children.

The article, titled "The Flight from Marriage," documents a trend among Asian women who marry and have children later in life -- or not at all. The article indicates that non-marriage rates for women in their mid-thirties are pushing 20 percent in the wealthiest countries in Asia, including Japan, Taiwan, and Singapore. And unsurprisingly, the non-marriage rate rises with education level. In Thailand, 13 percent of women with a high school education are still single by age 40, compared with 20 percent of university graduates.

The decline in marriage rates has also led to a dramatic dip in the fertility rate, to as low as 1.1 in Hong Kong -- fully half of the replacement rate. (Unlike in, say, Scandinavia, very few Asian births take place out of wedlock.) The overall fertility rate in East Asia has fallen from 5.3 in 1960 to 1.6 today. That's obviously not sustainable, and many of the countries affected are scrambling to offer incentives to persuade women to have children. Among the benefits being offered? Better work-life balance, including subsidized childcare and parental leave for both mothers and fathers. As the Wall Street Journal noted a few months ago, affordable child care has a significant effect on a country's fertility.

See that, Mr. Welch? That's work-life balance -- as an economic necessity. If it comes down to it, career women in the United States could always pull a Lysistrata and stop having babies until the men come around. But come on. We shouldn't need to get to that point.

Now, the reasons for the low marriage and birthrates in Asia are manifold, as the article describes, and include not only poor work-family polices but also inflexible divorce laws and rigid adherence to traditional social roles. (According to the article, the average Japanese woman does 30 hours of housework to a man's three -- talk about Chore Wars!) Because the tradition is for Asian women to "marry up," it's more difficult for educated and successful women to find a husband whose status matches or exceeds her own.

But the relationship between work-life policy and birthrate holds elsewhere as well. Take a look at Europe. The countries with the worst work-family policies are also, by and large, the countries with the lowest birthrates. Germany, for example, has notoriously bad work-life policies -- and a birthrate around 1.41 children per woman. Those countries with the highest birthrates, including Norway, Sweden, and France, tend to provide parents with the most support.

Business in a capitalist society has one goal and one goal only: to make money. This is often given as a justification for denying the value of policies that help employees achieve (or even attempt) work-life balance. But fertility trends show that this attitude is hugely shortsighted. There's no question that a career is now an option for most women. And the trends show that, when given an all-or-nothing choice between career and family, many women will choose career.

An aging population is a huge financial burden. It makes no sense to disincentivize reproduction. We simply can't afford to.

Joan Williams is the author of Reshaping the Work-Family Debate and Unbending Gender. She and Rachel Dempsey are co-writing an upcoming book about gender bias against professional women.