Historically, that might be true, but that is because historically it made sense to have more children in order to eventually gather more food or earn more money. Birth rates are dropping all over the place. Even in countries like India with traditionally very high birth rates. We are entering into a post-ubundance world, resources like food and clean water are becoming increasingly scarce and increasingly expensive. It makes no sense having babies if you’re not sure you’re going to be able to feed them.