WHAT DO WE KNOW ABOUT THE TIMING OF FERTILITY TRANSITIONS IN EUROPE

The Princeton project on the decline of fertility in Europe (the Europ ean Fertility Project) suggested that this historical fertility transi tion occurred virtually simultaneously in a wide variety of economic a nd social environments. This finding has been cited widely as evidence for an innovation/diffusion view of fertility transitions. We demonst rate that the demographic methods used to date the fertility transitio n in Europe-primarily I(g), and (to a lesser extent) the Coale-Trussel l M&m indices-may fail to detect the initial stages of a fertility tra nsition and therefore cannot be used as the basis for strong statement s about the timing of transitions. We review these measurement problem s and their implications for the current understanding of the European fertility transition.