According to some, “factoids” that suggest a looming retirement security crisis can be misleading. Andrew Biggs, a resident scholar at the American Enterprise Institute and a former principal deputy commissioner of the Social Security Administration during the George W. Bush administration, told Remapping Debate, “There’s a huge number of assumptions and calculations embedded in these final product numbers you get. When you say, ‘here’s the retirement index, and it’s X,’ well, there’s a [lot] of stuff that goes into getting to X, and some of those choices are going to be controversial.” For example, he said such studies often set a universal target replacement rate — often 75 percent of one’s pre-retirement income — when in reality, target replacement rates might be “more dispersed” depending on one’s “real” pre-retirement standard of living when adjusted for the presence of children in a household, and on one’s income level.

Biggs’ own conclusion, based on a model which aims to make that adjustment, is that “most Americans, both current retirees and future ones, appear to be reasonably well prepared to support themselves in retirement.” He wrote in a follow-up email, however, that there is “an uptick in the share of people who are under-prepared” and that, “over time, the number falling short may rise.”

Monique Morrissey, an economist at the Economic Policy Institute, agreed that modeling necessarily required the exercise of judgment in making assumptions. She noted, however, that, as a rule, “If you’re low income, your replacement rate should probably be higher, and if you’re higher income, your replacement rate can be lower, because if you’re low income, there’s just less give there.” That is because, compared to high-income retirees, low-income individuals generally save less during their working years, and, upon retirement, come to save less in taxes paid compared to wealthier retirees.

 “You certainly don’t want to have a mainstream replacement rate below 70 percent. That’s usually the minimum…To be on the safe side, it should be a lot higher,” she said.

“I do agree on lower-income households requiring higher rates. How much higher? That’s hard to say,” Biggs wrote in an email.

Despite the presence of what Morrissey called “some room for debate” regarding ideal replacement rates, over the course of weeks of research and interviews Remapping Debate found that the vast majority of evidence points toward a serious and growing threat to retirement security.