The project found that divorce rates for couples with college degrees are only a third as high as for those with a high-school degree.

An Emory University study found that couples with a five-year age difference were 18% more likely to divorce, and ones with a 10-year difference were 39% more likely.

What's less clear is whether divorce and separation rates rise in a recession—financial pressures mean couples argue more but make splitting up less affordable.