Research from the nonprofit Employee Benefits Research Institute throws cold water on the notion that working until age 70 will set most Americans up for adequate retirement income. Jack VanDerhei, research director at E.B.R.I., says some studies have suggested that by working to age 70 — five years past the traditional retirement age of 65 — nearly 80 percent of pre-retirees, including lower-income Americans, could have adequate retirement income.