The reasons for falling fertility are less clear. Certainly, fertility rates have fallen in countries such as Denmark before reliable contraceptives were developed. The breakdown of the extended family which means more stress for parents. In a 'modern' industrial society the labour value of children is low whereas in peasant society children contribute to the labour force from an early age. With the provision of pensions, it is no longer necessary to have children as a support in old age.
More women are in work.
As standards of living rise, more wealth is needed to bring up children. Where infant mortality is low, fewer babies are needed to ensure the survival of the family unit. There is considerable debate as to whether population growth in the intermediate stage of the transition was a stimulus to the Industrial Revolution or a consequence of it, and whether the demographic transition will follow a similar course in less developed countries . Extended Family Penguin Dictionary of Sociology 3. Demographic Transition Penguin Dictionary of Sociology 4.