Upward Mobility

 Ran across a statistic about the Forbes 400 billionaires so did a search with this result:

"When we first created the self-made score [see the article for an explanation of how they scored], we went back and assigned scores for the members of  the 1984 list. Less than half of them were self-made. By 2014, 69% of the list was deemed self-made. Fast forward to the present list, and that figure has inched up to 69.5%. All but one of the 18 newcomers this year are self-made.   [Oprah Winfrey is an example of someone who's entirely self made]

I don't know how this compares to other nations.  But China is an easy case:

The pandemic has proved no match for China’s wealth juggernaut. The total wealth of the China’s 400 Richest soared to $2.11 trillion, from $1.29 trillion a year earlier. The 64% gain was due to the easing of capital-market rules and an economic rebound that enabled China to pull ahead of the world’s other large economies in recovering from the pandemic. Nearly two-thirds of the listees saw their fortunes climb in the past year. The minimum net worth needed to make the list rose to $1.55 billion, compared with $1 billion a year ago. 

While not everyone on this list is also on the overall Forbes list, we can, I think, assume that many (almost all?) of the Chinese billionaires (I still have trouble comprehending the concept when typing it) are "self-made".  Some proportion of them are likely children or grandchildren of the bigwigs of the original Chinese communist party.