"Marist Institute for Public Opinion surveyed 1,235 Americans and found significant differences in almost all aspects of happiness between those who earn less than $50,000 and those who earn more—measures of their quality of life, free time, health, spiritual life, feelings of loneliness, expectations about aging, etc. Researcher Susan McCulloch told LearnVest that the $50,000 mark is when you start to see those significant differences. This poll is a much smaller study than the 2010 Princeton University one that suggested $75,000 was the magic income number, but it may be that, as LearnVest suggests, somewhere between $50,000 and $75,000 is the sweet spot."