In 1990, there were 12 OECD nations with wealth taxes similar to Warren's. Today, only four remain....Though politicians like Sen. Bernie Sanders praise Denmark and Sweden as paragons of democratic socialism that the U.S. should emulate, both nixed their wealth taxes in the '90s because too many rich citizens were just pulling their money out of the country. This capital flight resulted in lower rates of entrepreneurship and relative economic stagnation.......France tried a wealth tax for more than a decade, starting in 2000. That helped push an estimated 42,000 millionaires out of the country. They didn't pay the tax—they just left.