Most married men claim Social Security benefits at age 62 or 63. This is well short of both Social Security's Full Retirement Age and the age that maximizes the household's expected present value of benefits (EPVB).
This results in a loss of less than 4 percent in household EPBV. But essentially the entire loss is born by the survivor benefit, which falls nearly 20 percent. As many elderly widows have very low incomes, early claiming by married men is a major social problem, according to Steven Sass, Wei Sun and Anthony Webb, authors of "Why do married men claim social security benefits so early – ignorance or caddishness?"