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Jumping Malthus’s shadow

Although I had planned some longer blog posts about the interaction of the natural and the social worlds, how they collide and also drain away from one another specifically here in Victoria BC, I need to blog first about an intriguing book I’m currently reading: A Farewell to Alms by Gregory Clark.
Book cover of A Farewell to Alms by Gregory Clark
I was initially annoyed by Clark’s focus on what he calls the Malthusian regime, the entire pre-Industrial Revolution period in which people all over the world had more or less existed at subsistence levels – a condition not to be confused with starvation, but more with stasis …I think. That is, under the Malthusian regime, a society can’t jump over its own shadow, and it somehow always lands again in the same place.

Admittedly, I skimmed a lot of the book’s first third because I’m not an economist and the detailed data on death rates, birth rates, interest rates, medieval wills, and whatnot went over my head. Right over my head went most of Clark’s to-me-incomprehensible formulae that combine the driest of economic theory with the Greek-est of mathematical symbols. Parts of the book are literally in a language I don’t know how to understand.

But…! But now I’m on Part II, The Industrial Revolution (pp.193 ff.), and now Clark explains how the shadow was jumped.

Last night, on p.197, I read the passage that explains, for Clark, the factor that drives post-Industrial Revolution growth:

Growth is generated overwhelmingly by investments in expanding the stock of production knowledge in societies.

The statement looks simple, but it is somewhat complex, and brilliant. Let’s examine it. (Note: apologies to Clark if I’m getting this completely wrong, but here’s my take.)

  • Production knowledge refers to knowledge about how goods and services are produced, whether it’s manufacturing or medicine or food production or ideas. In the pre-Industrial Revolution period, the ecosystem of knowledge around production didn’t expand all that much – people didn’t do things in new ways, they did most things the way their parents and grandparents or tribal elders taught them to.
  • The stock of production knowledge refers to the whole ecosystem built on, around, and through the various production knowledges (plural – for you can break them down).
  • Investment in the stock of production knowledge means putting the spur to innovation, so that production knowledge actually gets better, deeper, more efficient. Innovation also implies (to my mind) being in it for the long haul, versus getting quick satisfaction and buzzing off to go lie on the beach.
  • Innovators plan and are capable of delayed gratification, for innovation doesn’t just happen, magically. Pre-Industrial Revolution societies, while often having a more “brutish” existence, nonetheless score low on the “capable of delaying gratification” scale. The ability to plan for the future and to delay gratification also goes hand in hand with literacy (knowledge transmission, creating wills to pass on wealth) and numeracy (being able to count beyond one-two-many, and therefore being able to estimate accurately and, again, plan).

So, to repeat: Overall growth – to benefit societies, to extricate them from the Malthusian regime of subsistence – is generated by investments in expanding the stock of production knowledge in societies.

Right after that sentence, Clark writes: “To understand the Industrial Revolution is to understand why such activity was not present or was unsuccessful before 1800, and why it became omnipresent after 1800.”

I’m definitely looking forward to reading (and trying to understand) the rest of this book. My interest is already piqued by his references to the benefits of density and urban agglomerations, and I see his ideas in the context of Richard Florida’s work on the creative class, too.

Here’s a link to a NYTimes review of the Clark’s book, by Nicholas Wade: In Dusty Archives, a Theory of Affluence.

A side note…

Clark has been criticized for emphasizing a genetic component to economic growth – he argues that values such as the ability to delay gratification as well as skills like literacy are almost genetically passed down through a society, often literally passed down, since in the period that led to the Industrial Revolution, the offspring of the very wealthy were most likely to step down in society. The rich had more surviving children, while the poor had fewer. But the rich under the Malthusian regime couldn’t ensure that their surviving offspring would have the wealth they enjoyed, and thus, the sons of large landholders became small landholders, sons of important merchants became small-time traders, and so forth. While that looks like a downward spiral, Clark argues that it actually helped spread the values of the rich into society overall. The offspring of the poor were less likely to survive, therefore there were fewer of them to propagate their values.

Sounds brutal and not very politically correct (or perhaps confirms the worst fears of revolutionaries), but it sure reminded me of some of the research featured recently in Seed Magazine on the Hive Mind and the eusociality of some insects, which indicates that behaviors, not just genes, are passed along by evolution.

Here’s a rather long extract from Seed Magazine’s article on the Hive Mind:

Amy Toth, a post-doc in genomic biology at the University of Illinois at Urbana-Champaign, says that many of the morphological differences among eusocial insects don’t arise from genes coding for body plan, but from differential nutrition. “For a long time,” she says, “people have known that nutritional differences are important in social insect societies. Queens are better nourished than other workers, and that’s very well established for many different species.” What Toth’s and others’ research is showing now is that there are nutritional differences among workers as well: “Skinny ones are foragers, and fat ones tend to do tasks in the nest, such as brood care,” she says. What’s more, they are able to trace the mechanisms behind those differences down to interactions on the genetic level.

Her work, along with that of Gene Robinson, also at the University of Illinois at Urbana- Champaign, and Jim Hunt, shows that it’s not merely differential nutrition that leads to caste differences, but the fact that differential nutrition affects gene expression. A poorly fed larva’s gene that codes for, say, vision will be expressed at a different intensity and at different times from one who is well fed. So the individual with more acute vision will, as an adult, undertake tasks for which vision is important. The two insects share a genotype, but because their genes are switched on or off at different times, their life cycles and even appearance would seem to be those of unrelated individuals. In ants, which are more sophisticated, differential gene expression leads to radical morphological differences, such as wide divergence in head and mandible size, and even the presence or absence of wings, all macroscopic differences that one would usually ascribe to genotype.


The life cycle of a paper wasp colony begins with a foundress, a female wasp who, at the end of the previous autumn, mated with a single male and managed to survive the winter in hibernation. In spring, with the male’s sperm still living inside her, she begins to construct her nest, into which she deposits fertilized eggs that will become the first generation of female workers. As the larvae develop, the foundress feeds and cares for them, though not very well.

Hunt says the ones that are fed only by the foundress are poorly fed, and though they are destined not to reproduce, they are, surprisingly, not born sterile. “When they emerge,” he says, “they are reproductively ready to go. They have the physiology of a noneusocial, solitary wasp. They have their reproductive physiology switched on.”

But because they were poorly fed, they are not fully developed. Their bodies are soft, and they cannot fly for the first day or so, so they stay in the nest. This is something, Hunt says, that a solitary, noneusocial wasp would never do, and it has nothing to do with a mutation. Because their reproductive system is ginned up, this first generation is primed for maternal behavior; what they find while hanging around the nest is that there is a second generation of larvae already present and in need of nourishment. So because they cannot fly away and seek the food they need to develop their ovaries, they instead rear their mother’s young, their brothers and sisters. The energetic cost of mothering eventually causes their reproductive systems to shut down entirely, and they will remain sterile the rest of their lives.

On the other hand, the females of this second generation, which are called gynes, emerge from the larval state fat and healthy, but with their reproductive systems not yet active. They stay in the nest and continue to accept the attention and food provided by the workers. Toward the end of the summer, when the food sources start to dry up and the workers return to the colony with less and less to share with their siblings, the gynes will leave the nest and, if they are lucky, be inseminated. They will then hibernate, and, if they survive the winter, attempt to found their own colonies. Meanwhile, the worker will have died at home. Their life cycles could not be more different, though their genotypes are the same.

While humans aren’t insects, the emphasis on nutrition and how it affects genetic expression, which in turn determines social behavior, seems resonant with the kind of situations that economists study: how well are people doing? How nurtured or well-fed are they? What can they afford?

Clark has been a busy worker bee, gathering a ton of data. Even if non-economists don’t understand it all, his book is well worth reading.


  1. As I’m in an economics department, I happen to have a PhD student working on this topic. She’s looking at how knowledge gets diffused in a really poor community in Laos. Her conclusion is that some methods of introducing knew knowledge lead to rapid diffusion, but speed of diffusion is not closely related to equity in the benefits experienced. Previous social status is an important determinant of benefits.

    I haven’t read Clark, but it is of course the case that ‘ability to delay gratification’ is a product of wealth, not genes.

    Comment by melanie — July 16, 2009 #

  2. Thanks for the comment, Melanie – I’d be really interested in your perspective on Clark’s book. If you get a chance to read it, let me know what you think. There were aspects that drove me bonkers in the first part, but I’m finding the 2nd part very interesting. (Full disclosure: I am not an economist! 🙂 )

    Comment by Yule — July 16, 2009 #

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