A new study by Matthew Rutledge, Alice Zulkarnain and Sara King reports that:
- The lifetime earnings of mothers with one child are 28 percent less than the earnings of childless women, all else equal, and each additional child lowers lifetime earnings by another 3 percent.
- When examining Social Security benefits, the motherhood penalty is smaller than the earnings penalty. But mothers with one child still receive 16 percent less in benefits than non-mothers, and each additional child reduces benefits by another 2 percent.
- The motherhood penalty is almost negligible among women receiving spousal benefits, but mothers who receive benefits on only their own earnings histories see significantly lower Social Security income.