Arnold Kling  

Clark, Malthus, and the Time Frame

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Hindsight Bias... Arnold on Clark...

Bryan is not happy with the Gregory Clark version of the Malthusian model.

I admit that I was unhappy with it, too, but I think I now understand it better. I don't think that graphs help, because one of the most confusing things is the issue of time frame.

I think of Clark's Malthusianism as describing humans as a herd grazing on a meadow. When the herd is thinned, by disease or war, the remaining beasts have more on which to graze. That's the "bad is good" story.

A bad year for grass (the bad harvest scenario) starves a lot of the herd, which is bad. But then next year, when grass is back to normal, the survivors eat well because of the thinner herd.

So the time frame is an issue. Yes, bad things are bad in the very short run. But then there is an adjustment process back to the Malthusian subsistence equilibrium. And it is during that adjustment process that the "bad is good" story comes into play.

Interestingly, technological change is not good in either the short run or the long run. It moves so slowly that all it does is allow for more population to live at subsistence. But then we hit the Industrial Revolution, and technology finally starts to out-pace population.


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COMMENTS (6 to date)
caveat bettor writes:

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General Specific writes:

" But then we hit the Industrial Revolution, and technology finally starts to out-pace population."

One of my interests is the role of energy in the industrial revolution, the technology of energy and the abundance of energy that was opened up by (a) the steam engine--allowing coal to be used to mine for more coal and (b) the combustion engine--and it's reliance on oil.

I'm not a doomster, but there could be malthusian limits in our future as energy supplies peak--including wars to secure the remaining supplies.

Many libertarians find any discussion of malthus anathema, but it's possible they are suffering from a form of bias. Maybe hindsight bias, particularly those who are fans of Julian Simon.

Buzzcut writes:

I agree that the steam engine was more important than anything else.

The middle ages were more technologically sophisticated than most people give it credit for. Unfortunately, the energy sources available for milling and whatnot were nothing more than wind or water power. That limited the spread of technology to... places that had exploitable wind and water power (duh).

But with a steam engine, you could have your mill or factory pretty much anywhere.

Dennis Mangan writes:

Plagues, famine, and war don't all have equal effects on a population. A measles epidemic, say, might kill a lot of people in a short time while leaving the rest perfectly healthy after a couple of weeks. Likewise something like dysentery might constantly kill a fraction of the population while leaving the rest untouched. So things might not be all that bad even in the short run, which would affirm the "bad is good" thesis.

Bruce G Charlton writes:

AK right, BC wrong.

Indeed Bryan is being uncharacteristically obtuse about this, in all three of his postings. Maybe he missed the Glaswegian wit and irony involved in Clark's 'bad is good' comments?

Michael Sullivan writes:

Interestingly, technological change is not good in either the short run or the long run. It moves so slowly that all it does is allow for more population to live at subsistence. But then we hit the Industrial Revolution, and technology finally starts to out-pace population.

That seems about right, but there's the interesting issue of one of the most important pre-industrial technological changes: agriculture. This was a big change, and it appears to have been *negative* for the median peasant, basically keeping them at the same subsistence level as hunter-gatherers at the cost of more onerous labor, while allowing a privileged few to live significantly above subsistence.

In a malthusian model, redistribution has massive utility consequences, and some technology enables such redistribution.

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