Malthusianism: Theory vs Data

Like Curunir, I found Robin Hanson's post on the "Dream Time" interesting. What struck me most is his prediction that our descendants will fall back to Malthusian economics: as the population grows, there are less resources for everyone, and the average wealth per capita is barely enough to survive.

Briefly, Malthusian economics, which held for all of history prior to 1800, is as follows. Start with the per capita wealth at subsistence levels. As technology improves, wealth grows. This allows people to have more children. Now there are fewer resources for everyone, so average wealth falls back down to subsistence levels.

Since 1800, in the First World, the dynamic has changed. As societies progress and accrue wealth, people generally decide to have fewer children, and the population stabilizes. Technology continues to improve, and per capita, people become richer.

The Malthusian skeptic of today sees all of this as temporary. His argument is:

* Forget the term "people". Think rather of "replicating beings". These beings have a strong tendency to make as many copies of themselves as possible.
* There are limited resources in the universe.
* The more beings there are, the less resources each can have.
* Technology can help us use our resources more efficiently, possibly making more resources available to everyone, but there is a limit to how much technology can do this.
* There might be some--or even a large majority of--beings that decide not to make many copies of themselves, but all it takes is a tiny subset that multiply fruitfully, and soon these fecund rebels will replace their less fertile cousins.
* Sure, we do not currently live by Malthusian economics, but sooner or later, Malthusian economics has to re-assert itself. Our wealth and abundance is temporary.

This is one instance in which the theory seems compelling even if it's counter to current trends. It's also depressing to me since I always thought of progress as a given, with people getting richer all the time. The only arguments I can think of against Malthusian re-assertion are that:

1) Beings could decide to enforce limited replication.
2) We don't know everything there is to know about physics. Resources may not be as limited as they appear today.

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Factor in strong property

Factor in strong property rights.

Well, first I will mention that I think we are currently grossly underpopulated given modern technology.

Now back to property rights. Suppose a woman has 100 children. What are they going to do? Some of them will find gainful employment. Those children will no net enrich those around them - their employers, their customers. Some of them will turn to property violations to sustain themselves, but strong property rights will eliminate them from the gene pool (and so the woman has an incentive not to have them at all - since they are a waste of her energy). The remainder will be parasites, i.e., they will be unable to offer value for value to anyone. Because of strong property rights, they will be stuck at home. The woman also has an incentive not to to have them either, because they uselessly deplete her resources.

The woman who desires to maximize the survival of her genetic line will therefore optimize. She will have few enough children so that she can then afford to endow them with the gifts that will make them useful to others, i.e., employable. If she has more than the optimal number, then the excess will die and her investment in those will have been wasted.

Property rights internalize costs, and the cost of having too many children is internalized to the genetic line.

However, maybe about ten years ago I was reading a transhumanist paper, which I only dimly recall, which suggested that the mechanism of Malthusian impoverishment would be through economic competition. You can, of course, impoverish your competitors without violating their property rights, and so my above account might have missed that avenue. However, I am not sure this is a negative externality on net, because the only way you can out-compete someone is by offering better value for value. And I think it's the net externalities that are killer in the Malthusian nightmare. What a mother will want to do in response to this is make sure that her children are above-marginal contributors, because if they are not then, again, her investment in them will have been wasted.

Anyway, I offer these half-baked thoughts as a possible alternative to the Malthusian scenario.

Even so

Even with strong property rights, the majority of individuals will be near subsistence level. If some people with a majority of the wealth choose not to reproduce, and if their descendants stick with that plan, then later a majority of wealth may be with rich folks, but still a majority of people would be poor.

I'm not seeing it. As I

I'm not seeing it. As I understand the Malthusian argument, externalities play an important role. That is, if a parent has four children instead of two, then those four children aren't mainly going to be competing with each other for food - they'll go their separate ways and compete with strangers for food. That being the case, there is every incentive to have four, eight, sixteen, 32 children, since each additional child will mostly eat the lunch of some stranger, rather than the lunch of a sibling. But once you internalize the costs to the family, so that additional children take food out of the mouths of their siblings, then you're going to want to limit the number of children you have.

Property rights go a long way to internalizing costs. In that case, what's left of the Malthusian argument? Are you arguing that some parents will choose to have precisely enough children so that the children will all be poor?

Also, I'm not sure what "poor" really means. Bill Gates has a lot of stuff, but conceivably a "poor" person could buy a cheap virtual reality machine that gave him the subjective experience of wealth. Is that ruled out, or is that included in the definition or "poor"? If included, then poverty need not be miserable.

Anyway, this speculation seems to me to involve the distant future. The heat death of the universe might come first. Or the death of the human race.

Also, I'm not sure what

Also, I'm not sure what "poor" really means. Bill Gates has a lot of stuff, but conceivably a "poor" person could buy a cheap virtual reality machine that gave him the subjective experience of wealth. Is that ruled out, or is that included in the definition or "poor"? If included, then poverty need not be miserable.

I have not read the RH's article in full yet. Quick comment.

I think that's a really good point you raised there. Not only will that Virtual Reality Machine muddy the waters for the meaning of "poor" but also, perhaps, all subjective experience. Let's hope the fucker is cheap though eh?

He says:

When our distant descendants think about our era, however, differences will loom larger. Yes they will see that we were more like them in knowing more things, and in having less contact with a wild nature. But our brief period of very rapid growth and discovery and our globally integrated economy and culture will be quite foreign to them. Yet even these differences will pale relative to one huge difference: our lives are far more dominated by consequential delusions: wildly false beliefs and non-adaptive values that matter. While our descendants may explore delusion-dominated virtual realities, they will well understand that such things cannot be real, and don’t much influence history. In contrast, we live in the brief but important “dreamtime” when delusions drove history. Our descendants will remember our era as the one where the human capacity to sincerely believe crazy non-adaptive things, and act on those beliefs, was dialed to the max.

I think I object to the bolded statement.

Empirically false

Even with strong property rights, the majority of individuals will be near subsistence level.

Empirically false. It is weak property rights which hare associated wit subsistence living, and strong that are associated with low birth rates.

You have empirical data

You have empirical data about the future? What are next week's winning lottery numbers, if I may ask?

We have empirical data about the past

Stronger property rights correlate with a reduction in subsistence living and birth rates. We are already in the Malthusian future. Malthus was wrong.

You may be failing to

You may be failing to account for the fact that Hanson is talking about a post-singularity future, if I recall his argument correctly.

No mention of singularity

I don't know just looked at it and there is no mention of a singularity. I also dispute that poor and subsistence living are identical. Our poor live a far higher than subsistence living.

I don't know what it going to be like in the distant future but assuming that the majority will be at subsistence with strong property rights is not a good bet. A better bet is that there may not be strong property rights in the first place because the majority do not live with that.

If the world's population

If the world's population hasn't already peaked, it's not far away. The question is whether it will fall because of the lower fertility rate that is associated with the relative wealth and well being that comes with free markets or because of the starvation and wars that inevitably result from authoritarian central planners pursuing their greed for power.

Regards, Don

Nope

The current world fertility situation is an accident of current biological preferences.

What happens when we can upload ourselves into computers? If I can upload myself, and earn more than the cost of the computer I run on, then I am going to do so. And I am going to keep making copies of myself, because, why not? That will push the return to the jobs that my uploaded self can do down, and it won't stop until the uploads are break-even - they can only barely earn what they cost.

Same argument goes for AI. I believe uploading and AI are both basically inevitable. Therefore, Malthusianism.

What happens when we can

What happens when we can upload ourselves into computers? If I can upload myself, and earn more than the cost of the computer I run on, then I am going to do so. And I am going to keep making copies of myself, because, why not? That will push the return to the jobs that my uploaded self can do down, and it won't stop until the uploads are break-even - they can only barely earn what they cost.

For a long time that need not happen. For a long time, the greater the population, the larger the economy, and the more productive each person becomes. A large city can do more per capita than a small town. Economists have long advocated free trade between countries because that effectively increases the size of the economy, allowing greater division of labor in accordance with comparative advantage.

There will eventually be some hard limit reached, possibly something like amount of RAM or hard drive space to store all of you, but initially the greater number of yous available to sell labor product will be matched by an equally greater number of yous available to buy labor product, and so you will all enjoy greater, not less, wealth.

So why doesn't this happen today?

What happens when we can upload ourselves into computers? If I can upload myself, and earn more than the cost of the computer I run on, then I am going to do so. And I am going to keep making copies of myself, because, why not? That will push the return to the jobs that my uploaded self can do down, and it won't stop until the uploads are break-even - they can only barely earn what they cost.

This sounds just like what my Mormon friend is doing. He and his wife have made 6 copies of themselves, the cost being a middle class existence for the resulting 8 person family instead of an upper class existence for a 4 person family.

So Mormons engage in this behavior. But why doesn't everyone? Why don't people today multiply like rabbits? Why do most people in the First World decide to have fewer children than they could have given their resources? Why won't uploads decide to do the same (make fewer copies than they could)?

Let's take Mormons...

...as Hanson mentioned in his post. I have a Mormon friend who is making a very good salary, is 34, and is on his 6th kid. He and his family could live a very comfortable life with two kids, but he clearly prefers living a less materially wealthy life with 6 kids (so far). His fruitfulness has brought him back down to middle class.

He's like many Mormons I know: smart, hard-working, decent, and fruitful. If we extrapolate into the future, Mormons will outnumber the rest of us. Pretty soon, they'll make up the bulk of the human race, and thus, the human race will be multiplying like crazy, and we'll be back down to subsistence level wealth.

Even if this isn't realistic, there will be "Mormons" in the future, even if they're bits of code running on hardware. Some population somewhere will take the outbreed-everyone-else strategy. Who's to say they won't be successful?

We are grossly

We are grossly underpopulated right now, and we all benefit from each new Mormon born. In the distant future where we run out of resources, if property rights were strong then we may see parents carefully weighing each new birth, because of the resources that it would take away from its siblings, resources which would come out of the family's pool of resources, not humanity's, due to strong property.

I'm with you. Hanson, by the

I'm with you. Hanson, by the way, views this as a positive future, since he's (as far as I can tell) almost solely interested in maximizing the number of people, since he thinks even people in a Malthusian trap are "basically happy".

We are grossly

We are grossly underpopulated right now

I'm very curious, why do you think this?

John McCarthy convinced me

John McCarthy convinced me here.

But he says explicitly: I

But he says explicitly:

I offer no opinion about a "right" population, and I suspect that population will eventually be limited by a sense of crowdedness rather than by material considerations.

I don't disagree that the world "can" hold more people comfortably. My question is why you think that's necessarily desirable.

The main selfish reason to

The main selfish reason to want more people is to increase the size of the economy. The same thing happens when two countries open trade. Their two smaller economies become one larger economy. This increases wealth all around because it allows greater division of labor.

Your quoted reason to want fewer people is that it would be "too crowded". Really? Do you live in the middle of nowhere? If so, how did you send your comment? Clearly you choose to live in an area with far greater crowds than you absolutely must. The world can become far more crowded than it is now without you losing the ability to live in an area with the crowds you are used to. And meanwhile you will be richer thanks to the larger economy.

I had the same reaction

I found Robin's argument convincing and depressing as well. I agree with everything you say. I had an almost identical post in my mental drafts folder, actually.

Resources

The Malthusian argument plays population size off against resources. The assumption is that resources are limited, and that we're approaching some serious regions of scarcity. I think our best science indicates this is a false assumption: resources, material and energy, are a constant in the universe. Pair that with a constant increase in knowledge, and you have every reason to expect an on-going blossoming of the human situation -- as long as we use our smarts, which is not a foregone conclusion given the evidence of today's world.

I do not use this to argue for continual increase in population size. I like open spaces. I think such aesthetic senses will keep population size under reasonable control, if we broaden the educational base of the world's people.

Once more unto the breach...

Malthus, like Hobbes, screwed the philosophical pooch when he ignored paleolithic man and aboriginal societies. Also, advocating that population must be kept in check to avoid the (Malthusian) trap sounds a lot like eugenics.

Population drops as the govt assumes family functions

but it will not help because food can now be turned into auto fuel.