The seminal theory of economic growth is the Solow Growth Model (technically, the Solow-Swan model). The model can be easily expressed mathematically.
I have never liked the model, nor its later variations.1 The intuition behind my dislike was that societies — and indeed different ethnic groups within societies — obviously varied enormously in their capacity to use, to “put together”, the factors of production. They also vary enormously in their capacity to generate factors of production: specifically capital, the produced means of production. The model implies that there will be a general convergence between economies that has not happened.
Updating the model by including human capital was a gesture in that direction but did not fix the problem with the model, which is much more basic. The update attempted to grapple with the failure of investment to flow to poorer countries and, by implication, the long-term, systematic failures of foreign aid. The failures of foreign [aid] also supported my intuition.
The most recent (2024) Nobel memorial was for work that also directly supports my intuition — how much institutions matter for economic growth. The long-term economic growth literature — identifying culture as very much mattering for economic growth — also supports my intuition.
Skills and knowledge (human capital) are basic
To explain why the entire approach — basically, fiddling with some version of the Cobb-Douglas production function — is fundamentally mistaken, we need to go back to the origins of human economic growth. I mean, right back — all the way to foragers.
What are the original forms of capital? Well, there are tools, which are the original form of physical capital. But without the skills to make and use the tools, they either do not exist, or they are useless.
So, we start with skills and knowledge, with human capital. It takes almost 20 years to train a young human forager to be a subsistence adult — that is, to forage as much nutrition as they consume. The need to stuff the human brain with skills and knowledge — and the need to grow a brain that can be so stuffed — is why we have the most biologically expensive children in the biosphere. The need to impart skills to biologically expensive children is fundamental to the dynamics of all human societies.
Human capital — skills and knowledge — is not an “add on”. It is basic.
So are social connections (social capital)
Foragers do not live as atomistic individuals. They live in families and (fluid) foraging bands. Families and foraging bands are vehicles for our highly cooperative subsistence and reproduction strategies.
That we are the tool-making and tool-using species lacking tearing teeth and claws with the most biologically expensive offspring is why we have highly cooperative subsistence and reproduction strategies. It is also why we are so much the normative species — enabling robust cooperation based on convergent expectations — and why we have prestige and propriety as forms of status.
Both these forms of status represent currencies of cooperation. Prestige grants people status for doing things which are risky, clever, hard, entertaining. It is status by conspicuous competence. It provides a way to reward people for engaging in activities which generate wider social benefits — what economists call positive externalities. It also encourages people to want to associate with you.2
The other form of status — propriety — grants status to those who uphold the norms of the group. In particular, it wields stigma against those deemed to have violated those norms. It provides a way to punish people for engaging in activities which generate wider social costs — what economists call negative externalities. It helps solve the free-rider problem regarding the effort to enforce norms.
Reversing (i.e. perverting) status patterns so that people get prestige from victimhood — extending to various forms of failures of competence or even wildly anti-social behaviour — while stigmatising people who conspicuously successful (as oppressors or exploiters) is deeply destructive of human flourishing.3 We can see this pattern currently operating in “progressive” US states, and especially cities, but murderous versions of it operated in various Communist states. These things affect economic activity, but cannot be discerned by a Cobb-Douglas production function.
It is not true that scientists have never discovered Homo economicus. Unfortunately, Homo economicus is not a member of genus Homo. It is Pan troglodytes (chimpanzees) playing strategy games in a lab. It is precisely because we Homo sapiens are more normative, allowing us to encapsulate the social conquest of the Earth, that there are billions of us and only a few thousand of them.
We — as a highly social, indeed ultra-social, species — engage in both individual and social calculations. Different cultures notoriously generate different patterns for, and balances between, such calculations.
1. The model has some utility for short-term calculations of growth.
2. As with any social benefit, the knock-on dynamics of prestige can be complex, but status from conspicuous competence is at the heart of it.
3. The November 2014 Shirtgate controversy — where a rocket scientist who had led the technically incredibly difficult task of landing a probe on a comet was publicly humiliated over the shirt he wore (a gift from a female friend it turned out) — represented conspicuous achievement (prestige) being trumped by feminist stigmatisation (propriety).
