Abstract
The main form of state insurance for long-term sickness in Britain is invalidity benefit. There has been a dramatic growth in the stock of claimants on this benefit since its introduction in 1971. A logit model is fitted to explain, at the individual level, the probability of entering invalidity benefit among over 50,000 women in 1977/8 and over 65,000 in 1983/4. Demographic characteristics played a powerful role in this model. Pay and benefit rates were also significant. Married women's entry probabilities were highly sensitive to local labour market conditions, and much more so than other population groups.