Obviously, you don’t need $900 million to be happy, but millions of Americans are stressed out living paycheck to paycheck. Psychologists from Purdue University and the University of Virginia recently analyzed World Gallup Poll data from 1.7 million people in 164 countries, and cross-referenced their earnings and life satisfaction. Although the cost and standard of living varies by country, they came up with a bold conclusion: The ideal income for individuals is $95,000 a year for life satisfaction and $60,000 to $75,000 a year for emotional well-being.