Many folks want to save the world. Especially young, single, energetic folks. Especially if they also get to:
Support their side in common political/etc. divides.
Affiliate with statusful prestigious folks who share their cause.
Network with other young energetic single folk in the process.
Show off being informed on progress, options on this issue.
Show off via gadget making, activity organizing, or art.
Show devotion and self-control via paying exceptional costs.
Have a vivid chance of making a huge personal difference.
But alas, while popular save-the-world causes offer many such perks, the cause of fertility, my guess for the world’s biggest problem today, is neglected in part because it offers few such perks.
The problem is this: If the falling-fertility trend of the last two centuries continues for another century (see fertility vs time and income here; more fertility stats here), we might well see a fully-developed world with fertility <1.5, lifespan >90, tax funded leisure for all over 65, and perhaps also >30% of GDP spent on “free” medicine for all. The resulting rapidly falling population would cut the scale economies that contribute to economic growth today. And strong intrusive innovation-limiting global governments might be required to keep young workers paying >75% income tax rates to support the retired masses. (Imagine young low-tax African nations forced at gunpoint to pay “their share” of the world’s retiree burden.)
Yes, robots might save us, yes even if they don’t growth will probably continue anyway, and yes eventually if incomes fell far enough or with enough time fertility would eventually rise again. So this is not directly an existential risk. But such a long stressful period would at least make us more vulnerable to other risks, risks that great filter considerations suggest are bigger than they seem. Yes, other potential problems may seem more serious than falling fertility, but remember those are mostly hypothetical, while falling fertility is actually happening.
This fertility problem is in principle easily reduced: just have more kids. But since that strategy offers few of the extra cause-perks listed above, I don’t expect fertility to become a popular cause. After all, we’ve seen this problem coming for a while, and it will take a long while to play out. So you can’t claim to be in the vanguard of a perceptive few who finally see the problem, or who will finally solve it. Elites have long been leaders in lowering fertility, making more-fertility folks seem lower status. The fertility problem doesn’t offer many excuses for new gadgets or networking events, and the joys of parenthood have long been explored in the arts. Furthermore, if you pick mates before having kids, having kids works poorly as an excuse to meet potential mates. Finally, your having more kids can only make a tiny dent in the overall problem, and the sacrifices you’d make to have kids would not be exceptional relative to your ancestors’ sacrifices. It is hard to tell grand hero stories here.
The good news is that we understand our likely biggest problem well enough that you can do something substantial about it, nearly as much as anyone can do. And, alas, that is also the bad news.
Now for many long quotes from two articles. First a recent article:
[The] Chinese fertility rate … now sits somewhere between 1.9 and 1.3, depending on who is doing the tabulating. … “In some major population centers—Beijing, Shanghai, and Tianjin among them—it appears that the average number of births per woman is amazingly low: below one baby per lifetime.” … By 2050, the age structure in China will be such that there are only 1.6 workers—today the country has 5.4—to support each retiree. …
America’s 2.06 is one of the highest fertility rates in the First World. Only Israel (2.75) and New Zealand (2.10) are more fertile. … China and America have yet to witness the effects of falling fertility because of demographic momentum. Populations increase even as fertility rates collapse, until the last above-replacement generation dies, after which the population begins contracting. The rate of contraction speeds up as each generation passes. No society has ever experienced prosperity in the wake of contracting population. …
In 2010, the Japanese fertility rate is 1.2. … the most prevalent new demographic archetype is the … “parasite single,” … college-educated, working women who live with their parents well into their 30s—not because they are too poor to pay rent, but because they spend their salaries on designer clothes, international travel, and fancy restaurants. The parasite singles are Japan’s biggest consumer group. ….
The problem with immigration as it relates to fertility isn’t the old complaint that the newcomers are out-breeding the natives. Rather, the problem is that the newcomers start behaving like natives too soon, with their [fertility] regressing quickly to the mean. … One of the best predictors of fertility is education. … It drops to 1.6 for [US] women with a graduate degree. One of the drivers of our fertility decline was the making of college de rigueur for middle-class women. …
Throughout history, governments have tried to get people to procreate. Augustus levied a “bachelor tax” on unmarried, aristocratic men. In 1927, Mussolini imposed a tax on all unmarried men between the ages of 25 and 65. … In 1944, … Stalin created the Motherhood Medal, given to any woman who bore at least six children. None of these attempts was successful. …
Singapore’s fertility rate was already in decline, having fallen from 5.45 in 1960 to 4.7 in 1965. … The government wanted to drive the fertility rate down even faster. .. Abortion was sanctioned—and even encouraged—at every stage. Parents who had more than two children were punished with no paid maternity leave and higher hospital charges for the delivery of the extra babies. Couples were encouraged to volunteer for sterilization. Parents who did so after having just one or two children were reimbursed for the medical costs of delivering those babies and their children were given preference in registering for the best schools.
The tactics were frighteningly effective. In 1976—just ten years after the campaign began—Singapore reached its target of 2.1. … But the rate kept diving, down to 1.74 by 1980. The biggest fertility decline came from the elites. … In an attempt to boost fertility rates among the elites, the government began offering big tax breaks to highly educated women who had three or more children. … None of it worked. … By 1984, Singapore’s fertility rate was 1.62 and falling. … Unpaid maternity leave for government workers was increased from one year to four years. … Yet the effort has met with total and unremitting failure. In 2001, Singapore’s fertility rate was 1.41. By 2004 it was 1.24. Today [in 2010] it is 1.1.
Next, a good 2006 Science article:
As fertility rates decline across the developed world, governments are offering big incentives for childbearing. Experts don’t expect them to have much effect.
The E.U. will lose between 24 million and 40 million people during each coming decade. … Population losses could bring a raft of negative economic consequences in the industrialized world, as well as greater stresses on social security and health care systems as the proportion of older citizens increases. … Some believe very low fertility rates are here to stay. … “While the additional [government] financial support is bound to be welcomed by parents, the overall effect on fertility is likely to be small.” … Both sides agree that falling fertility rates might be irreversible once they drop
below a certain level—what some demographers have begun to call the “low-fertility trap.” …
Demographers define a replacement-level [fertility] as 2.1—slightly more than a flat rate, to account for the small fraction of children who die before reaching reproductive age. Yet nearly all of the world’s industrialized nations have [fertilities] well below this magic number. … Only the United States, exceptional in the developed world, hits the replacement mark, with a [fertility] of 2.09. … Although [fertilities] remain high in some of the world’s poorest countries … the demographic transition is either under way or completed in most nations. … The process has taken place even in relatively poor countries such as Mexico, where [fertility] dropped from 6.5 to 2.5 between 1975 and 2005. … Demographers had [incorrectly] assumed that the decline would stop when replacement-level [fertilities] were reached. “During the early 1970s, everyone talked about the magic floor of replacement. … Nobody thought it would go below 2.1.” …
Several factors that make the [fertility] in the U.S. higher[:] … higher rate of unwanted pregnancies, … a lower unemployment rate, and a greater tendency for women to have children earlier in life, … [and] a stronger emphasis on religion and “traditional values” …
The key reason that economists and other experts are worried about low fertility rates is that they accelerate an overall “aging” of a population. … One way that many developed countries meet the challenge now is through immigration, which tends to increase the number of younger workers. Yet few demographers see immigration as the [long term] answer. …
The “window of opportunity” for family policies [to influence fertility] might actually be as little as 0.1 to 0.2 children per woman. … “Policies that would work would be so expensive that they will never be implemented.” … And some researchers have begun to think that it might actually be too late to reverse the trend in countries with the lowest fertility levels. … Once a nation’s [fertility] falls below 1.5, a downward demographic spiral sets in that makes it much more difficult to recover. … In Germany and Austria—nations with [fertility] of 1.39 and 1.36, respectively—young adults now consider their ideal family sizes to be as low as 1.7 children on average. “[In] Germany .. 30% of young people [are] not intending to have children. …
Reher maintained much of the world is now on the cusp of a prolonged period of population decline. The resulting population aging would lead to labor shortages even in developing countries. The result could be an economic disaster. … Santow … sees “nothing terrifying about a drop in the size of Europe’s population. Any decline will take time, and economies will adjust.”
This is a manifestation of the aging process itself. Curing aging and the problem goes away.
Your inability to understand why children can be social security, which is in fact a widespread and well attested phenomenon, seems to be based on trying to extrapolate from your own psychology, which is an unusual one to say the least.