This would actually be a solution for climate change.
I’d bet that parents who habitually scream at and/or hit their children would face a lot of pressure. No need to leave scarce children with negligent parents.
I’m not getting the imperative for fertiles to marry fertiles. You can marry anyone you want, you just need two fertiles to make a baby. Or one fertile and a sperm bank, to put it at one remove. It’s already been mentioned that humanity would be better off if breeders went for genetic diversity.
Who raises and pays for the kids will likely get a bit more fluid.
Teachers would need to look into alternative means of employment.
True. But I was going by your premise that nothing else changed.
In Herbert’s “The White Plague” (a widowed bioengineer creates a plague to kill only the female population), the tactic was polygamy - the surviving women had multiple husbands, with pretty much their choice of wealthy successful ones.
The math doesn’t work this way. From wiki.
The way the net increase or decease is calculated is to subtract the number of deaths from the number of births, add to the base population and calculate the percentage.
You are correct that there isn’t a drastic, immediate decline and that when fertility rates normalize with the next generation then population growth will increase.
Just for fun, I ran a number of simulations for population decline/growth based on the following factors, assumptions and wild-ass guesses, and also several points which I have absolutely no idea what would actually happen.
For the initial year or two, there will be close to a 99% decrease in the birthrate (as per Little Nemo’s calculation), as I assume will not be immediately obvious what the problem is and how to correct it.
Birth rates can be dramatically increased in most industrialized countries, and less to in less developed countries, for several reasons. The *average *number of live births for many of the less developed countries (LDC) is already five to seven per woman. There is a practical upper limit to the frequency of pregnancies, even with the best of medical care, which many of the women will not be able to afford. Health risks including AIDS and lowered high expectancies will also be a factor. The ability to cope with the problem will be more difficult in LDCs.
Male infertility is easier to deal with than female infertility. Sperm banks and an increase in the production of turkey basters will see to that.
Surrogate mothers would dramatically increase, and more favorable laws would be enacted. However, predicting if the average cost would decline or increase is beyond the scope of this WAG. Currently costs run in the $50k plus in the States and $20k plus for renting a womb in India. Unless the average cost were to dramatically decline, it would still beyond many families’ budget. There is also a limit to the number of IVF procedures performed, as it would take several years to ramp up the number of doctors, technicians and medical facilities available.
There would be a large number of adoptions from less developed countries. Possibly with quasi surrogate mother arrangement of sperm from the adopting families fathers. Poorer countries in the former Eastern European block would be popular. There could become more children of color adopted with a shift in demographics.
The less developed the country, the younger the next generation will become mothers, with a lower practical limit of 15 years old, although it wouldn’t be expected that all girls would start this young. In more developed countries, it would be more likely for late teenage to early 20s for starting children.
Obviously, there are too many factors for anything but wild guesses. However, by playing around with the birthrate, while keeping the death rate constant, in 20 years, the world population would decline to between 6.2 billion and 6.5 billion, before returning to the current 7 billion in 25 to 35 years.
However, not all countries are going to be affected equally. Countries with lower life expectancies will the hardest hit with a generation of so few children. Sub-Sahara Africa, for example will be completely devastated in 30 years, as the number of workers will be steeply declining but with insufficient replacements. Expect massive poverty and starvation.
The more advanced nations will suffer less and will be able to recover faster. However, there would still be a massive decrease in babies born for a 20 year period, with the corresponding social problems.
Japan will be particularly hard hit, as it already is struggling with a declining population.Wwith its xenophobia and isolation, it would be less likely be as aggressive as the US for adopting children from other countries. Expect its economy to go into free fall when the lack of new tax payers will bankrupted the country.
The US would likely be better off than most countries, with a population which has low resistance to adoption, surrogacy and other measures. Retirement age will need to be increased, more elderly people will live in poverty, but the country won’t be as hard hit as others.
WOW,
Lots of different impacts, the period in between this happening and the majority of the population dying would be the most interesting. I can see anarchy breaking out as the supply of labor isn’t able to meet demand.
Be a good time to liquify any assets you have. Share prices will plummet, as would housing prices.
They’d only have limited time to figure that out, as the infrastructure of developed countries isn’t designed for 90% less population
The idea of fertile women being rounded up as breeding stock would be a high chance, as would fertile men being hooked up to the equivalent of a milking machine to extract as much sperm as possible to be stored in developed places. In undeveloped countries potentially mass extinction as the 10% of fertile males try to match up with the 10% of fertile females.
If you read the thread, you’ll see that the the infertility problem is only with the people alive when the event occurs, and does not affect the next generation.
I’d love to see infertility appear among all women who chronically abuse drugs and alcohol- they seem to have no problem having lots of babies they can’t take care of! 
Everyone seems to be taking this as a bad thing, with the impetus to get those who can, to pump out as many babies as possible .
The planet is overpopulated now, with the overpopulation accelerating literally by the minute.
Its overcrowded, polluted and resources becoming more and more harder to access, so will in the near future become a lot more expensive, and less commonly spread throughout the population.
You won’t, in the probably near future, be able to just jump into your car and go for a drive, you’ll have to balance the necessities on their importance.
Can I visit the doctor, or should I do the weeks food shopping etc. ?
Because the cost of gas may mean that you can’t do both .
Will electricity be on only so many hours a day ?
How about water, how many hours a day will that be on ?
Or will fuel and certain other items be rationed for ordinary people ?
Soon there will be “Water Wars” in certain parts of the world as Fossil water runs out, and rivers cannot adequately supply the increased, and increasing demands on them.
And labour intensive industries are fast becoming a thing of the past with computers, the internet and automation.
Theres a good chance that people being born right now, may never have the opportunity to work at a real (As opposed to government funded Make work schemes ) job during their lifetimes.
And the very much reduced workforce will be paying to support them one way or another from their taxes, plus of course the cost of trying to control the increased crime rate that will almost inevitably occur when you’ve got a lot of young, bored, physically active people around who haven’t much money.
Far from a population reduction being a tragedy, it would be a godsend both for Humankind, and for the planet, its habitats, and its wildlife.
With the resources we have now, and a very reduced population, life would become paradise on Earth, literally.
With the added bonus of a hell of a lot less wars.
Widespread infertility ?
Bring it on !
Well, you’re right, I blew that math pretty solidly. The difference between births per year and death’s per year should have been 1.2% of the total population, or 70M. That much is fairly consistent with your Wikipedia info, which reports a difference of 78M:
I’m puzzled why the deaths per year are so much lower than I estimated (56M versus my estimate of 100M). 
If average life expectancy around the globe is 70 years, shouldn’t we see 1/70th of the population dying every year?