Posts in Demographics
Delayed Gratification - Why are global birth rates falling, and does it matter?

This is the final chapter in the first part of my long-running demographics project. In the previous chapter I described the quantum effect of fertility, which hypothesises a negative relationship between fertility and rising incomes as parents substitute quantity for quality in their reproductive decisions and child-rearing. But can the quantum effect explain why birth rates in one country after the other appears to be stuck below the replacement level, and why global fertility will soon drop below that same level? The answer is no.

To understand current and more recent post WWII global fertility trends—broadly since the 1970s—we need to introduce tempo effects to the analysis. Tempo effects describe the tendency of women to postpone the timing of their first child. By mathematical logic, prolonged tempo effects can drive significant population ageing, but a more fundamental question is whether birth postponement also has a lagged effect on quantum, or more precisely, cohort fertility. This chapter discusses these question in the context of the hypothesis of a Second Demographic Transition, SDT, and presents a number of case studies to explore the specifics of recent fertility trends in key countries and regions. The chapter finishes by discussing the idea of a fertility trap, and whether the increasingly accelerating decline in global birth rates are a problem, drawing on the recent polarisation in the debate on this issue.

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The BIS gets it wrong on AI/LLM and feminism & reproduction

The BIS has a Bulletin out on the usefulness of AI and large language models. They’re not terribly impressed.

When posed with a logical puzzle that demands reasoning about the knowledge of others and about counterfactuals, large language models (LLMs) display a distinctive and revealing pattern of failure. 

The LLM performs flawlessly when presented with the original wording of the puzzle available on the internet but performs poorly when incidental details are changed, suggestive of a lack of true understanding of the underlying logic. 

Our findings do not detract from the considerable progress in central bank applications of machine learning to data management, macro analysis and regulation/supervision. They do, however, suggest that caution should be exercised in deploying LLMs in contexts that demand rigorous reasoning in economic analysis.

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The Demographic Transition

This is the landing page for my most ambitious non-fiction project to date. My writings on demographics are scattered all over this blog—though my master’s thesis is a baseline for a lot of my thoughts—and so, incidentally, is the work of my late friend Edward Hugh on the same matter. Randy McDonald has been stalwartly keeping the old Demography.Matters blog up to date, an effort which is badly in need of a new more modern and well-publicised platform.

I have been thinking about and studying demographics and population dynamics for well over 10 years, and this is my attempt to synthesise my thoughts. I will warm up with a simple account of the demographic transition, posted below, before moving on to the principal components of this process; mortality and fertility. I will then, eventually, examine how demographics drive economic processes, principally via the effect of ageing on growth and capital flows, expanding on the work that I have already done. I will post this work in piecemeal fashion inviting comments as I go along before combining everything into a coherent volume. When Google first introduced its Blogger platform it did so, I believe, under the banner of perpetual beta, a spirit that I agree with. I will post a final, and fully edited, volume eventually, but I also want to draw back the curtain slowly and gradually, if only to keep up the publishing cadence on this site. The meaning of “landing page” in this context is no more than a repository for the list of references and the individual chapters, both of which will be updated here as I go along. Each chapter, however, will have its own independent permalink too.

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Japan's disappearing population

Japan invariably looms as the central case study for the economic and societal effects of rapid fertility decline, population decline and ageing. Japan is, measured by median age, the oldest country on earth, excluding the greying millionaires of Monaco and the some-5,000 people on British St. Helena. At the end of 2021, Japan had a median age of 48.4, well ahead of the second major country on the list, Italy, with a median age of 46.8. Japan is about to get older still. According to preliminary estimates, the country’s fertility rate fell further last year, albeit marginally, while the gap between births and deaths remained wide as ever. The number of live births fell by 5.0%, to 770.774, while deaths rose by 9.0%, to 1.57 million. Japan’s rapidly ageing population is the result of a quicker and more sustained post-1945 fertility transition than in other developed economies.

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