Over 50 years ago I took a course in demographics. A lot has changed since then. Then, we had gone through the baby boomers and a lot of experts agreed there was danger in being overpopulated, but some thought there were some natural brakes
The two authors studied lots of statistics, but more importantly traveled around the world and talked to a variety not only of experts, but also to ordinary people (if a little better educated). Recently saw both with Steve Paikin on the tv show "The Agenda" 5 years after publication of "Empty Planet" (2019).
Two factors have emerged in almost every nation to account for declining birth rates: the education (and empowerment) of women and urbanization. For ages having children was good for helping on the farm, but in the city children are more of an expense. Women are at long last learning how to avoid burdensome motherhood and enjoy life more.
The replacement rate for women to replicate themselves is 2.1 meaning they need to have 2 babies each plus a little more to allow for those who don't have any or only 1. Almost all of the developed world is below that number and even in most of the developing world the number is also declining. The global population has been climbing because of longevity increases and parts of the world where women have more than two babies. The authors contend that previous estimates are far higher than the reality and declining population will be dramatic.
It is not necessarily a bad thing, however there will be some negative effects.
Young people are innovators and older people are expensive with pensions and medical care while fewer people to generate the economy and provide services.
China after their experience with their one child policy are stuck with millions of men unable to find a female partner because when only allowed one child and the Chinese had a strong preference for boys and many abandoned girls. Many ended up adopted overseas. During the policy years both men and women learned that sterilization was the most effective birth control.
Brazil telenovelas effected women of all social classes if they watched them. The families depicted were small and the women all seemed to have more freedom. They appealed to both rich and poor.
Infertility is another factor. Naomi Klein in an effort to get pregnant learned about fertility issues. Chemical pollution is correlated to infertility, birth defects and miscarriages. see http://www.therealjohndavidson.com/2015/02/this-changes-everything-deserves-major.html
Both authors are Canadian and have noticed historical factors that have boosted population.
Clifford Sifton was the Canadian interior cabinet minister from 1896 to 1905 under Wilfrid Laurier and both were concerned that Americans were pushing towards the western border with Canada. The government took some immigration employees off salary and put on commission. Under Sifton, immigration authorities approached Scandinavia, Germany, Balkans, and Ukraine enticing many who helped secure the border against Americans.
On the other hand the government stopped Chinese immigrants after they had been instrumental in building the national railway. Jews from the St Louis ship were sent away and during World War II the Japanese were forced into internment camps.
Eventually the Chinese were allowed to migrate and Canada developed a reputation for helping refugees including Hungarians after 1956, the Vietnamese fleeing war conditions and the Syrians during their Civil War and most recently Ukrainians. The government uses a point system that evaluates which refugees or would be immigrants can help Canada. We also accepted a multi cultural life style that was more comfortable for non English immigrants..
My ancestors came to North America by boat from England, Scotland and Switzerland and some shifted from the United States by horse or on foot. My wife Sharon's ancestors also came by boat from Italy and Ukraine.
Quebec has a delicate situation because they not only needed to boost population, but wanted to maintain their French culture. They targeted French west Africa. My Brother in law , Ali came from Morocco to Ontario for education. After he married my sister the plan was to go to Morocco, however a stopover in Montreal offered a compatible situation with more Moroccans and as he was fluent in French (English and Arabic) the decision was made to live in Quebec. Their house proved to be an enjoyable stopover on my way to Nova Scotia to visit my daughter in school and develop a sales job and then he helped me open up Quebec for sales and vacationing. http://www.therealjohndavidson.com/2012/07/travels-of-salesman-part-3-quebec.html
The U.S. needs immigrants to maintain their standard of living, but some (example Donald Trump) think a key to getting elected is to cater to prejudices. Most of American Nobel prize winners were immigrants. Soon America will find it more difficult to attract necessary immigrants as many will find conditions at home better and there will be fewer of them.
Incentives do make a difference, but not nearly enough. Paternity leave, tax deductions even cash bonuses have to compete against other factors.
IVF is one tool to help slow down the decline. For those who were without hope there is now hope http://www.therealjohndavidson.com/2024/11/joy-film-about-ivf.html
Environmentalists have pointed out a major cause of climate change has been the burgeoning over- population. Urbanization can be good for the environment. High rise apartments can be more energy efficient and allow traffic to be more manageable.
The population mix has changed gradually, but seems certain to bend towards less with a greater proportion to the older. The right to work legislation and the generosity of pensions likely will be adjusted. We truly are all part of this change and perhaps we will act more compassionately as well as rational.