>>someone with 1 million dollars is astronomically more likely to make another million dollars than someone with 100 dollars, even if the two people are otherwise identical, and it seems pretty unlikely that wealth creation has much to do with the distribution we see.
Someone who scores 85 marks in an exam is more likely to score 95 with a little more effort than some one who scores 35 is likely to score 85 with a lot of effort. This is for a very simple reason that to get to 85 requires a lot of effort, which builds a whole range of human qualities along the way.
Note that the statement is that the two people are identical other than their wealth, so that in this case the difference in probability is independent of how the original million was acquired. That's the point.
Of course they're not the same. The point of the experiment was to show that the differences don't need to be taken into account to replicate in a model the inequality we see in reality. The implication is that, while differences between people clearly exist, they aren't necessary to explain inequality.
Someone who scores 85 marks in an exam is more likely to score 95 with a little more effort than some one who scores 35 is likely to score 85 with a lot of effort. This is for a very simple reason that to get to 85 requires a lot of effort, which builds a whole range of human qualities along the way.