There are several reasons why this title may seem to pose an eccentric question. By the second half of the nineteenth century England's preindustrial demographic regime had largely been transformed. External forces had removed the links between population growth and food prices, and between real wages and nuptiality. The balancing mechanism provided by these links, which had been so important in seventeenth-century England, was no longer needed. Economic growth had a momentum of its own, unhindered – perhaps encouraged – by population expansion. The preventive check concept therefore appears redundant by 1850, let alone by 1900. Yet Malthus's highly effective notion of the way that moral restraint, when applied to the postponement of marriage, can not only depress overall fertility in the long term in such a way that the balance between population and resources is made more favourable, but also act as a relatively short-run break when times have been hard, may prove to be more complex than had once been thought. The preventive check combines the effects of age at marriage and the proportion marrying. Both variables influence the level of nuptiality in ways that are only just beginning to be understood, especially among non-European populations.