It was also the first country to impose a female quota for board directors in about 400 publicly listed and state-owned companies, lifting the share of women to 40 percent, from about 7 percent in 2003.

All told, family policy, including a system of child care from a guaranteed place for 1-year-olds to after-school and vacation care, costs the Norwegian government 2.8 percent of gross domestic product. “These policies are expensive, but their cost is offset by the return in terms of female labor supply and tax revenues,” says Danielle Venn, a labor economist at the Organization for Economic Cooperation and Development. Even excluding oil, Oslo’s deficit of 5.4 percent of G.D.P. is a percentage point below the E.U. average.

It is a cautionary tale — and not just for Europe’s less productive, indebted southern rim, which was traditionally slow on women’s advancement. Other countries are passing austerity programs that risk hurting women’s work prospects. In Britain, for example, maternity and child care benefits are being cut, as are half a million public-sector jobs, most of which are held by women.

As many write the obituary of the welfare state, how much can other countries learn from the Nordic model?

Skeptics argue that all the Nordics are small and homogeneous countries where social cohesion is high. But Professor Erling Barth at the Institute for Social Research and Oslo University says economic incentives, rather than population size or temperament, explain behavioral patterns. “We are not all that different in Norway,” he noted.

Indeed, a number of large countries have recently started importing some of the social engineering: Germany, which with its 82 million inhabitants is 17 times the size of Norway, has earmarked two of 14 months paid parental leave for dads. The share of fathers taking time off with baby surged to more than 25 percent today from 3 percent in 2007.

France, Spain and the Netherlands are phasing in boardroom quotas; several others are mulling legislation.