This analysis suggests that if we want a sustainable welfare state which provides a safety net during unemployment but without eroding work motivation via personality damage, then we need to make sure that welfare policies are not causing extra children to be born to claimants. This probably conjures up ghastly images of draconican mandatory contraception programmes or worse, but the good news is that research from the USA and UK shows the reproductive behaviour of welfare claimants tracks the generosity of benefits: for example, UK data suggest that for every 3 per cent rise in benefit generosity there is approximately a 1 per cent rise in the number of children born to claimants. Moreover, this relationship is causal, since follow-up interviews show that claimants voluntarily increase contraceptive use if the generosity of benefits is reduced and vice versa. In the jargon of economics, these data allow claimants to be conceptualised as rational agents who adjust contraceptive use in order to maximise benefit take.