I don't think this conclusion is correct:

"In essence, the decline in birth rates is not a consequence of individual choice or even culture but a byproduct of a kleptocratic monetary system that has made child-rearing unaffordable."

Culture has a huge impact as well. As with the year 1971 in financial terms, you can look at the years in the 1960s where the contraceptive pill entered the market, and then you take a look at birth rates in the decades before and after!

Economic incentives may help a little in terms of increasing birth rates, but even though France and Germany have quite high rates of financial support for children, and schools and health care are free (paid through taxes), the birth rates is still below the level of 2.1 child per woman.

Though you may not like the analysis of Mary Eberstadt in her book, Adam and Eve after the pill, I think it's worth listening very carefully. It takes a culture the values the self-gift of parenthood and especially motherhood much higher to turn numbers around...!