Likewise, in aggregate, being raised with a single-minded focus on chess is probably not necessary or sufficient for being successful on the scale of the article. Certainly most attempts to breed prodigies fail.

Using a financial metric as opposed to a chess metric is an internal/external validity tradeoff that would support the claim that the parenting techniques used are useful in real-world scenarios. I think this is better because as many others have pointed out, how good you are at chess is usually not a factor in how successful a life you lead, whereas in the West, your net worth is basically a direct measurement of success.