Lesthaeghe, R. (2010). "The Unfolding Story of the Second Demographic Transition," Population and Development Review 36(2): 211-251.
This piece represents the author's response to critics of a theoretical innovation he developed, with a coauthor, in 1986. The innovation is that of the "second demographic transition," which argues that we are seeing a "sustained sub-replacement fertility, a multitude of living arrangements other than marriage, the disconnection between marriage and procreation, and no stationary population." This theory is rooted in three theoretical insights: first, the notion that people are now choosing to assume the role of parent, rather than having it thrust upon them; second, that small birth cohorts tend to have larger families as they experience greater economic opportunity than larger cohorts, and thus get married and start families sooner; and finally, that increased economic opportunity in the form of development increases the importance of Maslowian values higher up the pyramid, culminating in self-actualization, whether as a parent or else-wise. He reviews the evidence for a distinction between the two transitions: differential marriage and remarriage patterns; increased age at first parenthood; and differential societal constraints (specifically the difference between material needs and "higher-order" Maslowian needs). And while the second demographic transition would have been impossible without the first, the author argues that they are distinct and indeed antagonistic. He then argues that the transition is not geographically delimited, but can be found throughout Europe. We'll set aside the question of whether a phenomenon that can be described as "found throughout Europe" is not geographically delimited. He then argues that cases which appear to be disconfirming, by disaggregating the phenomena he predicts, are in fact confirming cases. This argument depends on his assertion that the second demographic transition is context-dependent. The author then considers whether there is data to support the spreading of the second demographic transition beyond the West (ah, there's the issue of geographic delimitation dealt with).
My take: First, if you assert that your soi-disant "universal theory" is, in fact, context-dependent, then what you have is not a universal theory. It is a Lakatos-degenerate theory that should be abandoned. In particular, if you think Cahn and Carbone's approach has explanatory power, then you have a serious problem with Lesthaeghe's approach. In addition, if your theory explains, using different causal mechanisms, both negative and positive cases, then it's not falsifiable - again, not science.