ABSTRACT
Past studies of changes in fertility in England and Wales have generally made use of one or more simple fertility rates—either the number of live births per thousand women aged 15 to 45 or the number of legitimate live births per thousand married women in the same thirty-year age-group. Apart from the distortion which may be introduced into these rates by changes in the age distribution of women within the thirty-year group, they suffer from a further inadequacy. Fertility rates lose most of their value unless they show, in addition to spatial, temporal, and social class differences, how these differences and changes are related to the measuring-rod of replacement. That is, we are interested not only in changes in fertility but also in the degree to which they affect a community’s ability to reproduce itself. From this point of view simple fertility rates are unreal.
