Royal Belgian Academy of Sciences.

This paper presents a narrative of the unfolding of the Second Demographic Transition (SDT) since the theory was first formulated in 1986. The first part recapitulates the foundations of the theory, and documents the spread of the SDT to the point that it now covers most European populations. Also for Europe, we focus on the relationship between the SDT and current period fertility levels. It is shown that the positive relationship between these two is not a violation of the SDT-theory, but the outcome of a “split correlation ” with different sub-narratives concerning fertility postponement and recuperation respectively for two parts of Europe. The second part of the paper addresses the issue of whether the SDT has spread or is currentl