Why fair coin flips end with one person owning almost everything: the yard-sale model of wealth
30seconds
Give 60 people 100 coins each and let them trade by fair coin flips, with the stake a fixed share of the poorer person's wealth. Nobody has any skill or advantage, and every bet is 50/50.
Yet the yard-sale model ends with almost all the wealth in one pair of hands. Run it yourself, watch the Gini coefficient climb, then turn on a little redistribution and see the pile-up stop.
Deep dive · 4 min
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