The United States may be the poster child for capitalism, but people living in China, India and Vietnam are bigger believers in the free market than Americans.

Pew Research surveyed people living in 44 different countries this spring. They asked a simple question: Do you agree with the following statement: "Most people are better off in a free market economy, even though some people are rich and some are poor."

Worldwide, two-thirds of those surveyed agreed, giving capitalism a thumbs up.

But the results get more interesting at the country level. In the U.S., 70% agreed that the free market is the way to go. Compare that to China (76% agree), India (72%) and South Korea (78%).

Vietnam dwarfed everyone though, with a whopping 95% in favor of capitalism.

The results are somewhat surprising for China given that the communist government has presided over a decade of incredible economic growth of over 7% a year.

"We've seen widespread support [in China] for the free market since 2002 when we began asking this question there," says Katie Simmons, a senior researcher at Pew. "They've consistently been one of the highest countries."

Simmons notes that China has enacted numerous reforms to open up the country's economy since the 1970s.

This latest Pew "global attitudes" survey shows that developing nations overall are more optimistic about the economy and the future than people living in developed countries. Parts of Europe are growing especially pessimistic.

Related: What does it take to get ahead around the world?

About half the population in both Spain and Greece no longer think the free market is the ideal. In fact, Spain, which still has an unemployment rate close to 25%, saw the largest drop in support for capitalism since 2007. The financial crisis and sluggish recovery have chipped away at support for capitalism.

The results for both China and the U.S. stayed almost exactly the same as the 2007 survey.

But the biggest doubters of capitalism among the 44 countries Pew polled can be found in Argentina. Only a third of those surveyed agreed with the statement that the free market system is best.

Argentina has struggled with price spikes for basic goods and several defaults on the nation's bond payments.