The 4th image is US fertility rates and overlaid on it is the causes of the fertility decline. Since we have established that less economy, is caused by less babies, and now we can establish less babies is due to contraception, we can state more contraception equals less economy. Lets examine the 1920s. With the introduction of family planning and there being now no real opposition ( https://en.wikipedia.org/wiki/Birth_control_movement_in_the_United_States ), baby making rates begin to plummet. This creates in society an excess of wealth because the economy had naturally evolved to include a higher rate of spending on raising children. When this money has no children to raise it gets used in other ways. We end up with the Roaring '20s and the stock market boom. You can see how such a small change in society (condoms) has enormous effects on its economics and culture. This richness of society allows all sorts of decadence to become affordable, but not only that, sex itself has no consequences. Sex itself no longer carries the risk of 20 years of raising a child. What a great time to be alive! How liberating (shoutout to Liberals). Does this not show that a liberal philosophy is correct? Well, no because in 1929 the stock market has no more of this excess cash, plus all the bank loans added on to it, to hold it in bubble territory. Any selling is met with no buyer who has not already bought in. The stock market crashes and all the wealth that was historically reserved to raise children evaporates into nothing. Now there is no children and no confidence in the economy resulting in the Great Depression.
One of the strange things about humanity is that when times are hard we have more children, and when times are easy we have less children. At first this seems illogical but when you examine the mindset of people in a third world country the answer becomes clear. Every adult has the concern about making sure their old age is secure. There are two ways to secure your old age; 1) money 2) children. If we have enough money (and that does not just mean your bank account, it could be a government pension, or a expensive house you can sell) you have less pressure to guarantee your future old age with family/children. A rich society has a tendency to favour money for old age security, and a poor society has no choice but to depend on children who will grow up to look after them. And the more desperate a person's situation is the more children they will have in the hopes that some survive into the future to look after them. This is why dysfunctional societies breed and functional societies do not breed. Contraception makes the 'not breeding' option even easier to achieve.
The 1920s introduced family planning, that is the unimpeded distribution of condoms allow the rich West to destroy their future economy. This begins about 10 years after the introduction (as discussed above) and so in the 1930s we have the Great Depression. This desperate time creates a lot of unemployed men. These men are feeling "emaculated" they cannot provide for their families as they wish, their days are long, boring and depressing. One of the cheap ways for those men to feel masculine and uplifted and pass time, and achieve this at no cost with the energy they have from not working, is to have sex with their wife. This, coupled with condoms now being unaffordable or unobtainable stops the collapse in the birth rates as shown by the chart. Bad times = babies.
part 2/4