Generation replacement in Europe since 1900

The author examines population dynamics in Western Europe during the twentieth century, with a focus on changes in generations' ability to reproduce themselves. He applies "the concept of 'generation replacement', based on 'net' fertility, [taking] into account the mortality rates to which a generation of mothers is subjected up to the end of reproductive life. The conditions in which replacement occurs are measured by the reproduction rate, or replacement rate, which expresses the number of daughters by which each of the women born [in] a given year will, on average, be succeeded. Replacement is ensured when the rate is higher than one. To reach this level, the generation's fertility must be all the higher as mortality conditions are unfavourable."