In demographics, it has long been known that when a nation reaches a particular economic plateau, the birthrate drops from large families to between 2.1 and 2.3 children per family, a no growth rate.
However, both government and the predominant culture can lower this birthrate even lower, by placing additional burdens on prospective parents. Often these seem benign, or even beneficial, such as setting minimal standards for education, health and prosperity. Each new requirement discourages a few more couples from having even two children, or any at all.
Other factors, such as employment, prices, taxes, residences; city, suburban or rural living; ease of contraception and abortion, and adult oriented entertainment come into play as well. And then, finally, religion and morality can either encourage or discourage having children.
Only one modern nation has ever succeeded in creating a baby boom, albeit unintentionally, and that is the United States. It achieved this through a peculiar combination of factors.
1) New cities, with far more adults of child bearing age than typical.
2) Mostly male (9-5) employment, with females taking the role of housekeeper, and wages high enough, and taxes low enough, for a one breadwinner household income.
3) A general lack of adult oriented entertainment, though lots of schools, churches, and other family oriented recreation.
4) Boredom, which was a critical factor in deciding to have children for many. If they could afford it, why not have children? It was something to do.
Since this is the only model known to work, if Italy, or Russia, or any of the other developed nations truly wish to increase their marriage and birthrate, this is the way for them to achieve it.
“However, both government and the predominant culture can lower this birthrate even lower, by placing additional burdens on prospective parents. Often these seem benign, or even beneficial, such as setting minimal standards for education, health and prosperity. Each new requirement discourages a few more couples from having even two children, or any at all.”
You have solved Riddle of the Sphinx. Very, very, few people can understand the marginal impact of policies like you mentioned. But I do think liberal leaders FULLY understand these impacts, and they are VERY HAPPY with the results.