Last week we learned that China’s population shrunk last year, for the first time in 60 years, by 850K, the net result of 9.6M live births, and 10.4M deaths. It is worth taking these numbers with a pinch of salt. Accurately accounting for some 1.4B people is difficult, especially down to a sub-1M difference between deaths and births. It’s possible that future revisions will show that China’s population has been shrinking since the beginning of the 2020s, or that it won’t start shrinking until 2025 or beyond. What is clear for anyone with even cursory knowledge of Chinese demographics, however, is that this headline was coming sooner rather than later. China’s fertility rate has long since declined below the replacement level, and all-age mortality is now rising as the population ages. But does it matter that China’s population is now shrinking?
Read MoreWhether you’re an evolutionary biologist, cultural sociologist or a neoclassical economist, the study of human fertility behaviour can be boiled down to an interplay between two immovable forces: the quantum and tempo effect. The first treats the fundamental question of reproduction; how many children to have, and how much resources to invest in each of them. In its simplest form, the quantum effect is the study of how much, if at all, women exert control over the quantity of offspring they produce. The extent to which they do—and almost all disciplines agree that they do in most social contexts—the analysis focuses on the conditions that determine the number of children, and how much resources that are devoted to each of them. It is an analysis of trade-offs, concentrated on the trade-off between the quantity and quality of offspring. How this balance is achieved represents one of the most crucial processes in the study of reproduction, aggregate fertility, and the demographic transition.
Read MoreMarkets are moving, and I’ll have more to say about that in due course, but we before we get to that, I am finally ready to present the third chapter in my running demographics project. The landing page for the project can be found here. You can get the PDF for the third chapter below, or via the landing page.
This chapter kicks off the description, analysis and discussion of fertility and birth rates. It is the first of, I suspect, three chapters on fertility. In it, I try to cover three bases. First, I cover the basics, defining the different ways in which fertility and birth rates are described quantitatively in the literature, and the distinction between these terms. Secondly, I summarise the stylised facts about the global fertility transition, when it began, and how it is going. My objective has been to strike a balance between the big picture and sufficient detail to allow for the discussion individual case studies across individual nations, or groups of countries. The key point, from both an empirical and theoretical perspective, is that fertility does not stabilise at replacement levels in the final stages of the demographic transition. In this way, the fertility transition is an ongoing phenomenon, in contrast to the picture painted by the stylised model of the demographic transition. Thirdly, I run through the theory of sexual selection as described by Trivers (1972), and used in Richard Dawkins’ seminal, The Selfish Gene. There are two reasons for this. First, the basics matter. The game of mate selection, which feeds through to how parents share the costs of reproduction and child-rearing, is crucial to understand why births occur in the first place. The idea that evolved behaviour described by Trivers (1972) can be used to explain phenomena in a modern context invites us to heed F. Scott Fitzgerald’s advice that “the test of a first-rate intelligence is the ability to hold two opposing ideas in mind at the same time and still retain the ability to function.” It is reasonable to expect that many phenomena observed in a modern society can be traced back to core evolutionary processes. But equally, it is unreasonable to go searching for an evolutionary explanation for every phenomenon that social scientists might be interested in, in a modern economy. Whatever the balance between these two positions, the link between modern behaviour and pre-modern evolutionary theorems is a constant source of debate and controversy in the literature on demographics and fertility.
Read MoreThe evolution of mortality through the demographic transition is as close as we come to a deterministic process in the analysis of population dynamics. Science and technology have become increasingly better at keeping people alive, a benefit that still seems to drive the human experience to this day. It’s possible to identify milestones through history such as the development of modern sanitation to defeat contagious air- and waterborne illnesses, the development of vaccines for specific illnesses, as well as overall technological development in the field of healthcare. It is a story about pinning down the causality between rising national income and technological development and the improvement in the human living condition in the past 250 years. Researchers still debate the relative importance and merits of specific drivers, but it’s possible to generalize, all the same. The story about of human mortality is contained in a few relationships, for the individual, between, and possibly within countries. It is a story about Nike swoosh-shaped, logarithmic and asymptotic curves, and the extent to which we observe deviations from such stylized relationships over time, and why.
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