"Demographic studies on cohort fertility have revealed that the birth decline in the [Federal Republic of Germany] was accompanied or even brought about by a considerable postponement in parenthood. By means of event history analysis and micro-simulation this article shows that the postponement of motherhood can be attributed to the expansion of the educational system that took place in the 60s and early 70s. Furthermore, changes in educational structure have contributed markedly to increased childlessness in the younger generation, whereas there is no relation between the reduction in family size and the structural changes in education. The impact of increased education on the family life-cycle can be explained by labour market theories, whereas traditional theories have neglected biographic aspects of fertility." (SUMMARY IN ENG)