They used the Gini coefficient for wealth, not income in this case.
After all, even before the high-tax welfare state, Sweden was characterized by an even distribution of income, low poverty and long life spans, the same phenomena that today are said to be the result of high-tax welfare policies. In 1950, before the high-tax welfare state, Swedes lived 2.6 years longer than Americans. Today the difference is 2.7 years.
A more reasonable view of why Sweden performs well on many social metrics has its basis in history and sociology: Swedes have for hundreds of years benefited from sound low-level institutions, such as a strong work ethic and high levels of trust and cooperation.
These cultural phenomena do not disappear when Swedes cross the Atlantic to the supposedly inferior “cowboy” country. On the contrary, they appear to bloom fully. The 4.4 million Americans with Swedish origins are considerably richer than the average American. If Americans with Swedish ancestry would form their own country their per capita GDP would be $56,900, more than $10,000 above the earnings of the average American.
The old Sweden, in contrast, has not done as well in economic terms. In 1960 taxation stood at 30 percent of GDP, roughly where the US is today. As taxes rose, economic growth decreased, with Sweden dropping from being the 4th richest country in 1970 to being the 12th richest in 2008. Swedish GDP per capita is now $36,600, far below the $45,500 of the US, and even further behind the $56,900 of Swedes in America.
A Scandinavian economist once stated to Milton Friedman: “In Scandinavia we have no poverty.” Milton Friedman replied, “That’s interesting, because in America among Scandinavians, we have no poverty either.” Indeed, the poverty rate for Americans with Swedish ancestry is only 6.7%, half the U.S average. Economists Geranda Notten and Chris de Neubourg have calculated the poverty rate in Sweden using the American poverty threshold, finding it to be an identical 6.7%.
Instead of building capital, Swedes go into debt: 27 percent of Swedish households in fact have more debts than wealth, compared to between 16 and 19 percent in the US. With middle class wealth formation being held back by high taxes, Sweden has ironically developed a more unequal wealth distribution than the US. The Gini coefficient for ownership is almost 0.9 in Sweden, compared to slightly above 0.8 in the US.