That’s the conclusion from a new paper from the National Bureau of Economic Research. The paper found that early boomers have only slightly more than 15 percent of their wealth in stocks, defined contribution plans or IRAs. Defined benefit plans, on the other hand, represent 65 percent of boomers’ pension wealth, and Social Security makes up over one-quarter of total household wealth. So how long will boomers have to delay retirement? One and a half months.