[jmharvey]

Afaik (and I watch this fairly closely) there hasn't been a study. There are a lot of anecdotes, typically of the form "a person won a few million but spent like they had an income of a few million per year," sometimes of the form "a person won a huge amount of money but it turns out money doesn't solve all problems," and sometimes of the form "a person won a huge amount of money and invested it poorly." But most people who win a big lottery are still rich a decade or two later.