Except your point doesn't contradict mine at all. The post-war economy offered a lot of job opportunities as well as social safety nets, unlike the 19th century. This was a factor, but it wasn't the only factor. Because it was also a period with bad contraception. Soon after contraception became more reliable, fertility rates declined. If financial stability was the only factor, why did fertility rates decline as soon as women had the choice? The population boom was also stronger among Catholics. What explains that other than a misogynistic culture?

The fertility rates in Germany persist in being low despite the country having a decent safety net. Might be because women never really liked having children. Perhaps, just perhaps, having rampant marital rape has something to do with the baby boom?