In Economic Preparation for Retirement, Michael Hurd and Susann Rohwedder found that 51% of the single people in the group of 66-to-69 year olds they looked at had a strong possibility of running into serious financial troubles in retirement. By comparison, only 23% of the couples in the study were at risk of outliving their savings. The group with the most retirement risk? Women who had not completed a high school education. Of that group, 73% are likely to run out of cash before they die.

Surprisingly, though, the study found that Americans are, on average, better prepared for retirement than many believe. The study looked at the finances of early baby boomers, who have recently retired or are near retirement. Hurd and Rohwedder found that on average 71% of the people they looked at had a very good chance of having enough money to fund their retirement. For college graduates, the number was an even better 89%…

Another factor that made Hurd and Rohwedder’s study more optimistic about retirement savings than others was perhaps a little more morbid. Hurd and Rohwedder classified a number of low-income households, despite their meager retirement savings, as adequately prepared for retirement because they assumed that poorer people are more likely to die at a younger age than rich people.