Overpopulation : inconvenience, and means to reduce it

The problem of overpopulation has been mentioned in a few essays.
For example, Does Our Civilization Have a Destiny by Mark P Aldridge
"to establish population limits...
a call for population growth restraint such that if we determine we can support only 5 billion people on this planet in comfort and stability, we reduce our population naturally over time so as to reach that number. "
All right, but more concretely, if you determine that you can support only 5 billion people on this planet, then how do you call yourself to reduce your population naturally over time so as to reach that number ? Just being wise and expecting others to be wise is not enough: you can't control what others do in their bedroom, or do you ? As explained in One Cannot Live in the Cradle Forever by Robert de Neufville
"But the greatest challenges may be political. Overcoming the technical challenges may be easy in comparison to using our collective power as a species wisely. If humanity were a single person with all the knowledge and abilities of the entire human race, avoiding nuclear war, and environmental catastrophe would be relatively easy. But in fact we are billions of people with different experiences, different interests, and different visions for the future. In a sense, the future is a collective action problem. Our species’ prospects are effectively what economists call a “common good”. Every person has a stake in our future. But no one person or country has the primary responsibility for the well-being of the human race. Most do not get much personal benefit from sacrificing to lower the risk of extinction. And all else being equal each would prefer that others bear the cost of action."
So concretely what did he propose ?
"Our species is the only one that fully understands and CAN control it's reproduction. This may mean that some people may have to wait 60 years before they reproduce; some may never reproduce. The concept of guaranteed reproduction must of necessity be ended. "
Well, I did not know about that concept of "guaranteed reproduction" supposed to be still holding. Many people "guaranteed" to me that I would find love when I reported that it was the vital need for me to escape depression, however facts did not follow, and nobody ever carried responsibility for the failure of this "guarantee".

Let's now have a look in Just Too Many People: Towards a Sustainable Future Earth, at Alan M. Kadin's method to reduce his population naturally over time so as to reach the number "~1B" he determined that he can support on his planet :

"This transition will likely take several hundred years, but it is important to start as soon as possible. This will require reducing the effective fertility rate to ~ 1 child. Given the biological and social pressures to encourage child-bearing, can this be achieved without coercion? All traditional societies and traditional religions have encouraged large families, which is why there are now so many people. Under these circumstances, is there any hope for a sharp reduction in the birth rate? I believe that there is, given that such reductions in fertility follow on population trajectories that are already present in many developed countries. Historically, women married young and started having children immediately. Now the trend is for women to delay marriage and child-bearing while they pursue education and establish careers. Previously, children provided the primary system of old-age retirement and care. This is transitioning to a system of government-provided pensions and elder care. Small apartments in expensive cities favor few children, or none at all. Childlessness is becoming more socially acceptable than it used to be. These trends are likely to continue, and need to be supported by governments"

Now in Israel Perez's essay Indeed, the problem is quite complex...
"So, we will consider that for a couple of decades the global population remains steady and then starts to slightly drop after 2050 (see Fig. 1). We believe that this is the most probable scenario because we assume that the world will observe the same trend as Europe (...)
 To attain this, we need, again, a united world that works under the same ideals. I think this is the most troublesome part.
The first step is then to agree what we want for our future. "
Hum, quite speculative and unreliable I would say. Just because developed countries happened to reduce their fertility rate, I don't trust any idea of expecting this to automatically work for any other country, for many reasons such as cultural reasons and genetic reasons, that not all people around the world behave the same. Also, I don't see any good reason to expect the raise of standard of living (assuming it to automatically imply a reduction of fertility, which I'm not sure of) to benefit any large fraction of the world anyway, may it be because of lower levels of natural intelligence that cannot support competition on the job market, or because of the exhaustion of natural resources that any start of development would induce.
And even if this natural decrease of fertility seems to work in our times, I dot not trust it to work in the long term, because, just if some genetic, cultural or other variation between kinds of people provides exceptions to this "rule", these exceptions will have a natural selective advantage and will therefore take over the world in the long term.

Why smaller is better

Let us first examine the stakes : what differences are there between histories (forms of world development) depending on the human population number, assuming they are the same kind of humans with the same diversity (say, comparing our population with a smaller one of the "same kind" as obtained by taking a random sample), and that, in each world, they keep their constant number in the long term (let us not wonder how now).

An essential feature in this one: a larger population makes the technological progress faster with respect to time, but slower with respect to the number of human lives (time multiplied by population).
Because more people at the same time means more possible sources of innovation coming at the same time, however they cannot be as fruitful when happening in parallel by a number of people living at the same time, as they could be if done by the same number of people living at different times. Because in different worlds at the same stage of development, each person contributes according to what he could find possible to contribute in the world which he learned some roughly fixed number of years ago, which was less developed if progress was faster to this point due to a larger population, than if it came more slowly. Actually, a major burden in this world, that consumes a lot of work by companies, instead of their own work of bringing new progress, is the work of adapting themselves to the progress provided by others. If progress was slower with respect to time, then companies would need less work adapting themselves to a rapidly changing world, and thus would have more available resources to bring their own contribution to progress.

In scientific research, it often happens for major discoveries to be independently made by several people at the same time. If these people were living at separate times instead of at the same time, the discovery would be made by the first one, then others would know that this discovery was made and would not need to repeat it but could work for further progress instead. Libraries would not be overloaded by works which accidentally happen to repeat each other because they were made independently. It would then take less work to only contribute to the things that were not written by others before. This smaller volume containing the same amount of knowledge would be easier to browse through. And the easier it is to browse through what was done without missing anything, the fewer risks there are to repeat something already done because we failed to find it already done.
You might say : in a bigger population there is a bigger incentive for innovation because the market is bigger. Yes but the market is only bigger at a fixed time ; this difference behaves no more as such a difference if you integrate the usefulness over a period of time, as the sales volume in a less populated world may be seen as still somewhat big with a similar total number of customers coming after each other instead of simultaneously.
For these future sales to also matter, if in a long time period (>10 years), there needs to be a smaller real interest rate, through a larger proportion of productive assets, which naturally comes as the volume of capitals coming from savings is no more wasted in more expensive ownership of land and housing.

Overpopulation causes inequalities of incomes in 2 ways :
As concerns epidemiology, a bigger human population induces bigger risks for viruses to develop and adapt themselves to infect humans, as they have a bigger experimental field for mutation and evolution in a population not yet immune to them.
As concerns the genetic evolution of humans, a bigger population makes it more complicated for positive mutations to spread, as it takes more time for each mutation to spread over the totality of the population. As a larger number of positive mutations appear and are partially spread in parallel, it makes more inequalities between people, and it complicates the possibility for all positive mutations to combine, especially in cases several mutations would be located at the same place of the chromosome.
Thus here also, the progress may be faster with respect to time but slower with respect to the number of lives.

In conclusion, if progress is conceived as a transition between a time of low technology and a time of high technology that would finally be stable and mature (solving its sustainability problems), but that makes troubles in between, a world with smaller population uses a smaller total of natural resources until it reaches its maturity ; moreover it uses them in a longer period of time while resources can regenerate themselves, and is thus less a burden for the planet.

Concrete means to limit population

Now that the stakes are clear, let us discuss the means. What can lead many people to limit their fertility, even many of those who would not spontaneously do so ?

Let us first consider the problem of reducing the currently existing push to fertility:
Abortion looks ugly, however anyway, giving birth is somehow criminal as any contribution to population increase urgently needs to be reversed sooner or later, and most other available natural or artificial means of reducing population are also tragic, so this one is not so bad in comparison, when a woman considers that having a child would be a trouble.

Now to push more seriously to population decrease:

Again, if something here may seem ugly, I am curious to hear about more decent and responsible alternatives.

External link : Transition Earth

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