It will take the world another 118 years—or until 2133—to close the economic gender gap, according to the World Economic Forum’s Global Gender Gap Report 2015, which launched Thursday. Today, women are earning close to what men were paid back in 2006, when the Forum first developed its Global Gender Gap Index.

The Forum’s 2133 calculation is based on the current snail-like pace of improvement. The gender gap in health, education, economic opportunity and political representation has narrowed by 4% in the past 10 years, while the gap in wage equality and labor force parity has shrunk by just 3%.

Of course, the situation varies globally. The U.S., for example, is expected to reach economic gender equality in 2059, according to the Institute for Women’s Policy Research. America ranks 28th out of the 145 nations on the WEF’s Gender Gap Index, putting it below most European countries, including the UK, France, and Germany, as well as some African ones: Rwanda ranks sixth on the list, while South Africa ranks 17th.

The best news comes from—where else?—the Nordic countries: Iceland, Norway, Finland, and Sweden, which occupy the top four spots in the index. In that past 10 years, Iceland managed to shrink the gap by 11%, which means the country’s men and women are on track to reach economic equality in a decade, says Saadia Zahidi, head of employment and gender initiatives at the Forum.

Why are these countries so successful in closing the gap? “They have had a long tradition of putting social equality as a central tenet of their development,” says Zahidi. “They have been doing that for the last 100 years.” In these Nordic nations—and in Sweden in particular—government policy has been reinforcing gender equality, something that most countries do not do, she explains. “For most parts of the world, policy changes are really slow.” In the U.S., “there have been a few changes and some experiments, but most organizations are still looking like they did 30, 40, 50 years ago.”

In order to close the gender gap, countries must actually change the social policy model, as well as educate women and encourage them to join the workforce, Zahidi says. Currently, most social policy is still based on the idea of a single-income household where a man is the breadwinner and a woman is the caregiver. The reality, of course, is that it is becoming increasingly difficult for a family with children to subsist on a single income, and women and men are sharing at-home responsibilities more and more frequently.

The best example of how social policy can affect a population is Sweden, which, in addition to being the fourth most equal country in the world in terms of gender, also has the third-highest fertility rate in Europe. This is in contrast to the 1980s, when Sweden’s fertility rate was among the lowest. What’s different? The country has introduced publicly-run services for children, support for mothers’ employment, support for father involvement, and support for single mothers. In essence, reducing the stresses of combining employment and parenthood has made Swedish parents want more children.

If they want economic parity—and thus economic prosperity—other countries are going to need to start take a leaf out of Sweden’s social policy book.

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