In terms of preparing for retirement, millennials have three strikes against them. First, because of limited access to retirement plans at work, millennials will struggle to build retirement savings, since experience shows that people have a great deal of trouble saving on their own. Second, they are less likely to have bought a home, and home equity is a valuable retirement asset. And third, they are more likely to be burdened by student loans, and young workers with student loans have less to stash in retirement plans and are more likely to end up at risk in retirement.

An easy way to gauge retirement preparedness is to measure the ratio of wealth to income—in other words, how much millennials have been able to save or invest in assets like 401(k) plans or home equity compared to their incomes. It turns out that the wealth-to-income ratio for millennials is not only below that for Gen Xers and late Baby Boomers now, it is also projected to remain lower through their lifespans.

Millennials’ lack of wealth in their 30s relative to earlier cohorts should be a source of great concern, given that they will live longer than previous cohorts and will face higher health care costs.