On upward mobility, the "American Dream"--and China?

The New York Times today reveals a fact that will shock many:  One has a greater prospect of upward mobility in China than in the United States.  This finding (which I'll not scrutinize here in terms of methodology; I'm hardly qualified to do so) flies in the face our cultural assumptions--not only about capitalism v. socialism/communism, but also more strictly about the United States v. China. Here's the gist of the article:

There are two 18-year-olds, one in China, the other in the United States, both poor and short on prospects. You have to pick the one with the better chance at upward mobility. 

Which would you choose? 

Not long ago, the answer might have seemed simple. The “American Dream,” after all, had long promised a pathway to a better life for anyone who worked hard. 

But the answer today is startling: China has risen so quickly that your chances of improving your station in life there vastly exceed those in the United States.

Journalists Javier C. Hernandez and Quoctrung Bui report on the reasons for this surprising conclusion, attributing China's primacy to "an economic expansion without precedent in modern history": 

Eight hundred million people have risen out of poverty. That’s two and a half times the population of the United States.

* * * 

Not only are incomes drastically rising within families, but sons are outearning their fathers. That means expectations are rising, too, especially among China’s growing middle class. 

Life expectancy has also soared.

That brings me to a topic I have explored on these pages (and on Legal Ruralism) in prior posts, such as here, here, here, here, here and here, which is deaths of despair and the the role of optimism--or in the case of the United States pessimism--and mobility (is it upward or is it downward?)  in relation to health and wellbeing.  See more here, including references to the work of Andrew Cherlin of Johns Hopkins University, who has theorized white despair in relation to, well, (among other characteristics) whiteness and the current lack of optimism among the white working class, who no longer expect to move up, but instead see themselves slipping backwards.