Refusing the Terms: The Care Ledger and the Arithmetic Behind the Falling Birth Rate

Across the developed world, fertility has fallen below replacement and continues to fall, while surveys consistently report desired family size near two children. This paper argues that the gap between wanted and actual fertility is not a mystery of values but a piece of arithmetic that prospective mothers perform and policymakers refuse to. Unpaid care work is a measurable subsidy from women to the paid economy: valued at replacement cost, it reaches roughly $184,820 per year for a full time caregiving mother (Salary.com, 2024) and $10.8 trillion annually worldwide (Oxfam, 2020). The paper constructs a Maternal Ledger: an expected-cost calculation in which a woman prices not the average partner but the tail risk of abandonment, using observed dissolution rates (61 percent of unmarried parents separate by a child's fifth birthday) and observed child support recovery (roughly 64 cents of each dollar owed; about a quarter of custodial parents receive nothing). Under current terms, the expected maternal share of a child's cost is roughly 61 percent for an unmarried mother before counting her unpaid hours or her wage penalty, and a standard $5,000 baby bonus covers about 2 percent of the gap. The model yields a decision rule - proceed only if the plan closes alone - and three instruments: pay for the work, require a pre-posted maternal security endowment held by the mother, and, where private posting fails, state provision as poster of last resort. Marriage-payment evidence is reviewed: outcomes track not the size of transfers but who holds them and whether the obligation can be discharged. The paper closes with explicit falsification conditions.