Adam Ferrier questions the truism:
I came across an interesting study today by Gardner and Oswald (2007), Money and mental wellbeing: A longitudinal study of medium-sized lottery wins. In short they tested if people who had a medium sized lottery win (approx. $3,000 - $300,000) were happier. They did the study under quasi-experimental conditions, including creating a sample size large enough to make the findings reliable. In short they found people who won money in lotteries were psychologically happier as a result of their win - even up to two years later. A financial windfall made people happier.