Millennials said in a survey they needed $525,000 a year to be happy. Here's what a Nobel prize winner's research says about money and happiness.

• On average, respondents to a new survey said they needed $1.2 million in the bank to be happy.
• Millennial respondents said happiness would come from a $525,000 annual salary.
• Nobel prize winner's research suggests that there is a limited link between money and happiness.

If money can buy happiness, a new survey suggests each generation may have a different idea of what that price tag would be.