Today in ubernerd blogging: Bryan Caplan doesn’t buy Robin Hanson’s assertion that growth is not forever.
I’m baffled. You don’t have to be a sci-fi guy to think that in the next century we’ll get working virtual reality. And once we have that, why couldn’t economic growth of 1% (or 10%) continue forever in simulations? In the real world, we can’t all be emperor of an infinite universe. But I don’t see why every one of us couldn’t preside over our own simulated utopias?
As for all this talk of atoms: Economics is about value, not matter. As long as people regard vivid virtual goods as acceptable substitutes for actual goods, how can the scarcity of atoms stop everyone from having everything he desires?
I don’t think this is right. In the end even mental states must be represented by states of matter. Thoughts, I believe, have a one-to-one correspondence with configurations of the brain. At some point there must be a limit to our ability to reconfigure brains in new and interesting ways.
We should also recognize that there are a finite number of molecules in our brains. (Actually, I think we can do this with neurons but even if we assume that even re-jiggering minute structures of neurons corresponds to different thoughts). Thus there is a finite number of combinations and configurations of molecules. Thus there are a finite number of thoughts and feelings. At some point we will reach the end.
Now what we are arguing here is that either humanity is reaching the carrying capacity of our region of the universe or that we have maxed out the sum of human potential. Neither of these is likely to actually happen in my opinion.
Much more likely is that human population will drift towards and finally reach extinction long, long before we hit these constraints. I see relatively near term extinction as highly likely because modern technology is mitigating the reproduction instinct. Obviously birth control plays the major role by allowing sex without reproduction.
The ability to support ourselves with capital investments made during our working lives means that the need for children to support parents in later life is falling. This reduces the need for children.
An ever increasing range of entertainment technology makes perpetual adolescence more attractive.
Put together these factors suggest that we will reach the point were global population is contracting rapidly. Suppose that sometime in the next century global population peaked at 10 Billion and then began to decline at 2% a year. In another 1000 years, humanity would be gone.
I don’t think this is a particularly dark state of affairs, however. These days we mostly focus on the transition costs associated with an aging society, but it is important to remember that the long term effect of a shrinking population is increasing wealth.
I see the last human being on earth as being extremely happy, extremely wealthy people living in a subtropical extended adolescence. They will look and feel 22 until the day that they will die. They will want for nothing material. And they will spend their last days dancing on the beach, blissfully unconcerned about the end of humanity.

14 comments
Comments feed for this article
Monday ~ September 21st, 2009 at 11:47 am
TGGP
I think the “demographic transition” is temporary. Evolution will select for resistance to it. Steve Pinker once said if birth control grew on trees, we would have an instinctive fear of it like we do snakes today. There already exists variation in use of birth control, and some it is simply due to poor planning ability (remember that loss of function is easy to evolve). The future of humanity may be a combination of Phillip Longman’s “Return of Patriarchy” and Mike Judge’s “Idiocracy”.
Monday ~ September 21st, 2009 at 3:42 pm
Karl Smith
I think that if humanity will survive it will survive because people evolve some other mechanism for promoting birth rates. However, the vast majority of species go extinct.
Monday ~ September 21st, 2009 at 8:10 pm
teageegeepea
You mean “some other mechanism” that I didn’t refer to? Have any candidates?
Most species do not go extinct because of a failure to breed.
Monday ~ September 21st, 2009 at 10:44 pm
Karl Smith
No – I think your variation in use of BC is a good candidate. My point was that yes IF humanity is going to survive it will evolve a fear of BC or lack of a desire to stop children, or maybe in the future everyone will be descended from Nadia Sulaiman.
However, thats IF we don’t go extinct. Also, yes failure to breed is rare but so is the ability to separate breeding and sex. I doubt LACK of sex will be a feature in human extinction. Perhaps, wide spreed BC usage so that everyone can have as much as possible, but not failure to have sex.
Monday ~ September 21st, 2009 at 5:19 pm
Apex
This is an unexpected argument in a world were people are worried about over-population and the UN projection medium case is for a stable population level of around 9 billion through 2300 (high is 35 billion, low is 2.3 billion).
Dinosaurs and Mamoths are species that are taylored to a certain environment. The environment changed and they had no mental or collective ability to adapt to it.
It does not seem to be a justified argument to use the example of species that do not possess the mental or collective abilities to affect their species’ survival as a reason to expect human extinction (there is no species other than humans that have any ability to take pro-active efforts on behalf of the entire species to affect change towards preserving the species. We didn’t possess the collective ability in our caveman days but we do now).
This argument seems to be the exact opposite of the argument you used to argue for universal availability of the “no aging” drug. It seems to me if there was long term evidence of the decline of human civilization tending towards likely extinction, all efforts around the globe would be put into preserving it.
Why would the argument you used in the drug case not apply here?
Monday ~ September 21st, 2009 at 5:35 pm
Karl Smith
I think the never Dorian Gray Pill is unlikely to be found. If it was found then it would change everything, including my guess as to the future of humanity.
Tuesday ~ September 22nd, 2009 at 1:12 pm
Apex
I think I might not have made my point clear. I was not suggesting the Dorian Gray Pill would prevent extinction. I was saying that you used the argument that if such a pill were to exist all of humanity would put its efforts towards making it widely available regardless of what those costs were. Would it not follow that once it was clear that humans had decided not to reproduce that every effort would be forth to find ways to continue the species either through encouraging reproduction or finding an alternative means of doing it?
Tuesday ~ September 22nd, 2009 at 4:39 pm
Karl Smith
Not necessarily. The Dorian Gray Pill affects your individual life. Extinction is really about the rate at which we reproduce.
Now, if there was a single extinction level event that was going to kill all living beings then I see us doing everything to stop it. However, if we slowly drift towards extinction because the reproduction rate is so low then not necessarily.
Though TGGP’s point that whatever humans are born will more likely be born from people who do want to reproduce at high rates is a good one.
Wednesday ~ September 23rd, 2009 at 12:51 pm
Apex
That’s a good point about the single event versus the slow slide. You are correct that the situations are not exactly comparable.
Monday ~ September 21st, 2009 at 9:31 pm
Noah
Just to quibble…there’s no evidence to indicate that the Universe contains a finite number of atoms…we’ve never found an “end” to the Universe, and in fact may never find one…
Tuesday ~ September 22nd, 2009 at 7:06 am
Dan
Caplan is wrong. He doesn’t seem to understand that “value” can be traced back to the exploitation of natural resources. doesn’t matter how many levels of abstraction exist between them. Take his forever growing VR utopia, at first he may actually use less energy and matter as he ups the efficiency, but he will hit a physical limit in that soon. So to maintain his 1% compound growth of his VR utopia he will have to increase his use of matter and energy at 1% as well… So does Caplan have a exponential universe available with no physical limits like the speed of light? I doubt it.
Tuesday ~ September 22nd, 2009 at 8:38 am
Robin Hanson
I also replied to Bryan, at OvercomingBias.com. Conditional on our lineage not going extinct, do you agree that growth rates must eventually slow, and per capita wealth must fall?
Tuesday ~ September 22nd, 2009 at 1:19 pm
Karl Smith
I think that growth rates much eventually slow down.
I don’t know that per capita wealth must fall.
Thursday ~ September 24th, 2009 at 12:41 pm
Hanson on Fertility « Modeled Behavior
[...] the population part is true as well. I didn’t recognize that when Robin first mentioned it in my comments but he is [...]