How much would fertility rate need to drop for the world to stabilise at 2 billion people in 200 years time? Would the world with this amount of people be vastly more peaceful and prosperous?

  • $\begingroup$ Your second question is far too opinionated to be answered with SE's format - you need to edit this to something either measurable or researchable. As to the first question, research the world population milestones or just world population factors and expand your question, as a 2B population has not existed in a while and it would take more than just fertility rates to move to that point (researching South Korean fertility rates related to work hours might be a good starting point). $\endgroup$ – LinkBerest Sep 29 '18 at 2:17
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    $\begingroup$ How is this related to world building? What I personally find weird about this question is that you make no mention of regional differences. Assuming this is about world building, how do you turn some number into something useful? Any person on Earth knows that there are significant differences across the globe. While the question can be asked just like you did, it still makes me wonder about said world building aspect. $\endgroup$ – Raditz_35 Sep 29 '18 at 3:05
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    $\begingroup$ Well, the world population was around 2 billion in 1940. So I'm going to suggest no, it won't be vastly more peaceful. $\endgroup$ – GrandmasterB Sep 29 '18 at 3:15
  • $\begingroup$ I will also note, this is the third question asked on the site with similar warnings. Please take a look at our help center and try to formulate questions to match the requirements of the site so we can better help you build your world. $\endgroup$ – LinkBerest Sep 29 '18 at 3:17
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    $\begingroup$ And as a followup to @JGreenwell's comment, this is your third question and you haven't so much as taken our tour. Your questions are consistently downvoted and one of three has been closed. Stack Exchange employs automated banning procedures (that have nothing to do with us) that will soon impose a question-ban. As a friendly warning - you need to start paying attention to the site. $\endgroup$ – JBH Sep 29 '18 at 4:30

Wealth and Prosperity Cannot be Predicted This Way

I can kinda see your logic "if there were less people that means more resources for everyone!" Problem is, that simply isn't the case. As a population shrinks GDP and industrial output shrink with it proportionally. In addition, what is considered valuable and what measure by which prosperity is determined changes with cultures over time. Ultimately though, it is simply not possible to determine how wealthy or prosperous a culture will be by simply knowing it's population.

Propensity for War is Not Intrinsically Related to Population

Again, I see your logic here. "More space, more resources, less people, less reason to fight!" If I pointed out that the last time we had a World War the population was about 2 billion it might hamper this idea. Additionally, despite our population exploding like never before in human history, wars are becoming both less numerous and less violent. The last decades since WW2 ended have actually been far less violent and warlike than at any time in the last several centuries despite our population explosion. But Again, much like economics, We cannot possibly predict how warlike or peaceful a culture will be by simply knowing the population.

I'm too Dumb To Calculate Population Decline

Frankly, calculating birth rates, death rates, and how long it would take is some math that is a bit beyond me, so I will have to pass on that section of the answer. I do not math goodly. Not even a little bit.


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