The fertility wars

The otherwise long-forgotten comment, from 2021, by Mr. Trump’s running mate JD Vance that:

If you're making $100,000 [or] $400,000 a year, and you've got three kids, you should pay a different, lower tax rate than if you're making the same amount of money and you don't have kids.

has resurfaced in recent weeks, and stirred up a lot of attention. The comment as stated is innocuous. As many have pointed out, the US tax code already offers families with children tax credits relative to individuals with no children, as indeed do most tax systems in the developed world^. But then again, Mr. Vance has also said that:

We are effectively run in this country … by a bunch of childless cat ladies who are miserable at their own lives and the choices that they’ve made, and so they wanna make the rest of the country miserable, too,

As Rachel M. Cohen explains in a recent VOX article, these comments, and their return to centre stage in the public discourse, can initially be seen in the context of the Republican party taking pot-shots at their main opponent in the upcoming presidential elections. Kamala Harris is childless, and is exactly one of those cat ladies that Mr. Vance is referring too. The popular Democrat, and political activist, Alexandria Ocasio-Cortez would be another. Cohen also pulls out a comment by Blake Masters, an American politician from Arizona, noting that political leaders should be married and have children. To go for the woman, and not the ball, is a low blow, but it is par for the course in US politics, and nothing less than the liberal left has done on several occasions to their opponents on the right.

But something more profound is at stake in this discussion. The political flurry in the US over the virtues of parenthood and a high birth rate is part of a much larger cultural moment in which the debate on the significance of falling global fertility is pitting two increasingly militant and unyielding sides against each other. We have trade wars, culture wars, even actual wars; we can now add fertility wars to the list. When Elon Musk, a US entrepreneur and businessman, calls Ms. Harris an “extinctionist”, because she has linked the reluctance of young people to have children to “climate anxiety”, he means it, just as he means it when he concludes that “the natural extension of her philosophy would be a de facto holocaust for all of humanity!”

How to get handle on this? With difficulty, but in the end, hopefully with precision and clarity. First, I will briefly show that the fertility wars have been fought for a long time. I will then draw the contours of three separate positions in the fertility wars today—on the Conservative right, on the left, and a feminist perspective—before offering a suggestion on where this discourse goes next, and where it ultimately ends up, if we are sufficiently unlucky or un-attentive.

The long arc of the fertility wars

The inquiry into the optimal size of the global population and the appropriate rate of reproduction has been a feature of public and scientific debate since the early days of civilisation, Izazola and Howett (2010). Confucius, Plato and Aristotle all treated the question of an optimal population size, mainly from the point of view of offering a foundation for sound government, and generally saw an expanding population as a good thing. The first concrete proposal for an optimal global population size came in the 17th century from Dutch scientist Antoni van Leeuwenhoek. Leeuwenhoek proposed in 1679 that the earth’s land surface could support no more than 13.4B people. This estimate was based on his calculation of a 1:13400 ratio between the landmass of the Netherlands and the earth’s total landmass, from which it follows that the 1M people in the Netherlands at the time could be extrapolated to an optimal 13.4B for earth as a whole. Such estimates of earth’s “carrying capacity” vary dramatically, by anywhere from 1 billion to 1 trillion, according to McGuigan (2022).

The fertility wars entered mainstream economic and political history in the 18th century via the work of Robert Malthus. Malthus famously articulated the incompatibility of an arithmetic expansion in the supply of food and a geometric increase in the size of the population. Robert Malthus’ treatise in 1798 is a much richer work than implied by this often-cited mathematical rule with which his main tenets are identified. But the main point here is that his ideas peaked in relevance just as economic conditions were changing to disprove the core predictions of what has since been come to known as Malthusianism. Malthus failed to predict the industrial revolution and the demographic transition which, at least to some extent, sprang from it. Izazola and Howett (2010) notes that;

“Malthus’ theory and implications thrived at an academic level during a period which, in retrospect, would falsify them; the technological changes and demographic transition that took place in Europe during the end of the 19th century and beginning of the 20th have no doubt proved the specific implications and corollaries of Malthus’ theory wrong.”

After WWII, the population-optimist work of Danish economist Ester Boserup in 1965, and the pessimistic counterpoint propelled by the Club of Rome—in particular Denish Meadow's book The Limits to Growth, and Paul R. Erchlic’s 1960 book The Population Bomb—are important milestones in the battle between arguments elevating either rising or falling birth rates as paramount for prosperity if not the survival of the human race. Boserup turns Malthus' thesis on its head, arguing that it is population and population density which forces agricultural output to increase through technological progress rather than the former acting as a binding constraint on the latter. By contrast, Erchlic and Meadows gloomily predicted the collapse of the global eco-system by 1980 and 2025, respectively. History have since proven the gloomiest version of the Erchlic’s and Meadows’ tenets wrong, but it is difficult to falsify either of optimist and pessimist positions, as general principles. It is difficult to refute the idea that earth could, under some circumstances, reach carrying capacity such that Malthusian forces kick in to limit population growth. Indeed, in some countries, characterised by the absence of economic growth, high fertility and mortality rates, you could argue that such mechanisms are in place today. But it is equally difficult to deny that Boserup could well be right; namely that causality works from population growth to technological progress, which will allow earth to sustain more people as the pressure to innovate rises. The state of play in the fertility wars at the start of the 2020s play on themes discussed above. The argument in favour of pronatalism and a high birth rate is now generally defended by the right, while concerns about overpopulation has been adopted by the left, linked to worries about climate change. Both, however, are ultimately difficult to fit into the traditional political spectrum, especially in their extreme versions.

The (Right-wing) pronatal position

In my essay on the tempo effect of fertility, I attempt to break down the position concerned about falling birth rates into two components. The first starts out as a neutral argument, grounded in evolutionary theory, emphasising the mathematical fact that a population with below-replacement fertility will breed itself out of existence over time. This, in case you are wondering, is not optimal in an evolutionary model. In a modern context, this notion is linked to the idea that fertility trends in the 20th and 21st centuries have become maladaptive. The positive correlation between rising income/wealth and birth postponement as well as the shift in favour of less children with higher quality—the quantity/quality trade-off—lead to too few children to sustain the population in equilibrium. This position becomes a politically and culturally charged argument when it is linked to the idea of value degradation in society as a whole. Surely, a society whose values are not aligned so as to support its own propagation through stable birth rates is a sick society? Many conservatives today seem to think so.

The argument in favour of rising birth rates morphs into a more clear-cut right-wing program when it is linked to the risk that some groups, nations or lineages with low fertility are being out-competed, or out-bred as it were, by other groups. The classic version of this argument exists primarily on the political right in the fear that western cultures are at risk of being outbred and displaced by non-western cultures with higher birth rates. It is important to be upfront about the sleight of hand often performed by right-wing proponents of the idea that falling birth rates are a problem. When Conservatives sound the alarm on falling birth rates and de-population, they’re often assuming an us-vs-them position. The Conservative right is, in this context, primarily concerned with falling birth rates within its own group, nation or lineage, in opposition to high fertility of “competing” groups and nations, and often with respect to deleterious immigration of the latter into the former. This position has merit in the practical sense that the effect on homogenous communities— with falling birth rates—from immigration is an issue with huge political and social significance in many countries. Politicians, mainly of the left-leaning kind, do themselves a big disservice when they gaslight whole communities by branding them as racists for raising concerns about the social and cultural challenges from immigration. More extreme examples of insider-outsider dynamics, partially mediated by differences in birth rates, occur in regions with outright conflict across ethnic boundaries. Just ask Israel about the importance of its relatively high fertility rate in a region surrounded by countries whose stated goal it is to end its existence. Because the insider-outsider perspective on falling birth rates is so politically and culturally charged, it is important to isolate the more neutral position speculating and worrying about the general drivers of rapidly falling birth rates. This is simply a program emphasising the maladaptive conundrum of falling fertility rates in almost all cultural and national contexts as a function of modernity.

Cohen also links pronatalism to the politically and socially controversial debate, mainly in the US, on abortion. Conservatives remove themselves from any mainstream and academically-grounded argument in favour of stable birth rates when they argue that the threat of too low fertility for too long should be wielded as an argument in favour of restricting abortion and overall reproductive rights for women. Cohen cites Lyman Stone, a demographer, for weak empirical evidence that banning abortions lead to a persistent rise in birth rates, and another paper concluding that restricting reproductive rights can even lead to lower equilibrium fertility, and that it harms human capital formation. It seems to me a fringe argument at best to argue that curbing reproductive rights is an effective, let alone desirable, policy tool to sustainably lift fertility levels. Conservatives would do themselves an intellectual favour if they left out of the discussion about abortion rights the idea that forcing women to have children they don’t want, from unplanned pregnancies, is a solution to correcting endemically falling birth rates. It isn’t.

Left-wing climate anxiety and guilt by association

A significant chunk of the left political and cultural spectrum has adopted a neo-Malthusian posture in recent years, primarily linked to climate anxiety, as a counterpoint to the Conservative statement expressing concerns over rapidly falling birth rates. According to the most uncompromising version of this position, humanity is a burden on planet earth, and to the extent that modernity limits reproduction it is a good thing. In the extreme version of this argument, having children is a crime against the planet and its eco-system. The so-called “degrowth” narrative in developed economies is intrinsically linked to this argument. Some groups believe that the modern economy itself, and by derivative the people operating in it, are engines for environmental degradation.

In its most extreme version, this position is framed correctly by Elon Musk’s accusation that anyone arguing for lower fertility to counter climate change and to protect the environment is an “extinctionist”. After all, if humans are a plague on earth, the first logical step is to stop them reproducing. The second step is to start thinning out the herd of existing humans more generally. This isn’t hyperbole, but a logical end-result of linking the number of humans to environmental degradation and climate change. If the latter becomes a big enough crisis, the former becomes a serious problem. The main issue, as we shall see, is to figure who gets to stay, and who is surplus to requirements.

Climate anxiety is now explicitly embedded in the demographics literature. Striesness and Lutz (2014) develops a model in which they find that a sub-replacement level of fertility, at 1.5-to-1.8 children per women, is economically optimal, deviating from the position traditionally held that replacement level fertility—the rate at which the population naturally replaces itself over time—is most desirable. The controversy here is not so much that Striesness and Lutz (2014) argue that smaller relatively more educated populations offer better and more efficient macroeconomic outcomes over time. Lutz (2017) discusses population ethics and climate change, and arrives at the same conclusion; a smaller and more highly educated global population is most desirable, and that this only happens with fertility levels well below replacement levels for an extended period. That’s all fine, but only to a point. The controversial element is that the model in Striesness and Lutz (2014) incorporates an environmental variable such that more people lead to environmental stress and degradation. This is significant, for as the authors themselves say;

“If we were to care only about this environmental dimension, there would be little doubt that fewer people would be better and the resulting OLF [optimal level of fertility] would be zero.”

Striesness and Lutz (2014) settle on a weight of 20% for the environmental dimension in the end, but this is an arbitrary number, and it is unclear that a climate-concerned politician would not choose a significantly higher number.

The introduction of environmental concerns into the discussion about falling birth rates is part of a broader shift in the literature since the early 2000s. Most of the founding literature for the theories attempting to explain the rapid decline in fertility during the second demographic transition, as well as the early literature on the fertility trap, see low fertility in developing economies as a problem. More specifically, falling birth rates are perceived and analysed as something which can, and should, be adjusted by public policy. This is, in part, because low birth rates are seen as the result of women having fewer children than they would like. A more general theme is that falling birth rates are a problem for socioeconomic reasons, linked to the challenge for economic growth and public finances from population ageing due to rising costs of pensions and healthcare. Modern mixed capitalist economies work best over time if fertility is close to the replacement level, defined in almost all modern contexts as cohort fertility slightly over 2.

The idea that a fertility rate around 2 is optimal is still well-defended in the literature and more broadly by many policymakers and economists close to the political process, but it now faces stiff competition. How else can we explain why Karen Hardee, a US social demographer, presumably in all seriousness, can pen a piece arguing that pronatalism is a ponzi scheme;

The pronatalist movement is, we believe, inherently misguided. It is premised on the belief that ever-larger populations are needed to spur economic growth, which alone will lift individuals and communities out of poverty. But absent direct state intervention, this additional wealth generally accrues to those with established higher incomes, often at the expense of workers and consumers. Seen this way, pronatalism is a Ponzi scheme. It relies on new entrants to produce returns for earlier investors, with the burdens falling most heavily on women, who are responsible for the bulk of childbearing and child-rearing, often without adequate medical care or affordable child care.

Hardee’s attempt to erect a straw man for her takedown of pronatalism—that more babies are not a silver bullet for society’s economic and political ills more generally—does little to hide the obvious. Her position against pronatalism has nothing to do with opposition to the concept itself, but all to do with her disdain for the people who have adopted pronatalism into their political program. This tendency on the left to jettison even the most reasonable and sound ideas, simply because they’re being articulated favourably by the right is one of the most infuriating and dumb knee-jerk reactions of the left today. Instead of waging a battle over the concepts themselves—for example patriotism and pride in one’s nation and culture—the left moves straight to guilt by association. This, of course, is an age-old deficiency on the left, but it is depressing to see it in the wild, all the same.

Cohen, in fairness, attempts to offer a more even-handed profile of the side in the fertility wars worried about falling birth rates and de-population. She says that;

Not all pronatalists are politically conservative, and not all conservatives are particularly pronatalist. People with different backgrounds and ideologies are concerned about what a shrinking population will mean for future generations, though the movement does include anti-abortion advocates like Vance and Masters who have been more vocal. Still other card-carrying pronatalists staunchly oppose coercing women into having children they don’t want.

Cohen also, however, laments that pronatalism has been co-opted by the right, again leaving the reader with the impression that the progressive argument in favour of policies to stabilise, or even raise, birth rates has been abandoned by the left, solely because it doesn't want to rub shoulders with right-win pronatalists.

The feminist impossibility theorem

It is natural for feminists to take a strong view in the discussion about the optimal level of fertility and birth rates more generally. But it is difficult to pin down a unified feminist position. In the first instance, it is possible to identify a defensive, mostly left-wing, feminist position juxtaposed by a right-wing conservative emphasis on traditional family values, marriage and relatively high birth rates. The former posture is adopted because many feminists perceive, correctly, that the argument in favour of raising birth rates is easily transformed into a statement about how women ought to behave, for the greater good of humanity. This is the argument that widespread birth postponement and falling fertility are a result of women making sub-optimal choices—from the point of view of the greater good—to pursue their careers, or other self-interests, downplaying their biological role, and duties (?), as mothers and vessels of human reproduction. This argument naturally rouses a feminist counter response identifying protanalism as chauvinist because it, in a modern context, forces many women to spend more resources on reproduction than they would like.

This quintessentially feminist position that women should be free to do what they want, regardless of the secondary effects on fertility rates is countered by, among other movements, the tradwives—traditional wives—sub-culture. This is a feminist movement embracing and emphasising the virtues of a traditional, and ostensibly Conservative, view of women’s role along traditional gender roles in which women cook, raise children, and keep the house clean, while the man goes forth into the world and earns the money. In fairness, the tradwives movement is more a counter-response to its more established feminist opposition, but as far as the general discussion about falling birth rates is concerned, it shows that both sides of the argument are able to enlist archetypical and virtuous ideal roles for women in their defence.

Motherhood is also up for grabs. In a recent The Nation article, Moira Donegan describes the dichotomy between two feminist positions, one, the natural birth movement, which emphasises the role of women as mothers and their unique reproductive importance, and a counter-position which sees this as a narrow and constricting interpretation of women in modernity. It is no surprise that feminism is conflicted about the correct response to rapidly falling birth rates. Feminism, by a broad definition, will invariably embrace arguments which favour many of the seemingly contradictory positions stated above. Of course, the uncompromising feminists want it all; the ability to reproduce freely and plentifully, while not forgoing any costs in the social or economic spheres. All power to them. Alas, empirical evidence, and theory, suggest that reproduction (still) comes with trade-offs and that the costs of such trade-offs are disproportionately born by women, especially in modern labour markets where the returns to human capital formation are non-linear. Even if it were possible to socially engineer an equalisation in the costs of reproduction between men and women—very difficult given initial differences in biology and behavioural shifts in response to parenthood—it is impossible to eradicate the difference within the female cohort. In fact, this difference is set to grow over time. For in an economy with non-linear returns to human capital formation, especially for younger women compared to previous generations, the relative economic return from forgoing reproduction either for a time or entirely are very high indeed. I call this the feminist impossibility theorem. It is impossible—save perhaps in a world where the birth of children is completely severed from the female biology^^—to reconcile all the positions stated above under a unified feminist moniker, exactly because some of the most contradictory perspectives all contain element which at some point have been, or are still, seen as feminist archetypes and ideals.

Pigeonhole this!

History shows that it is tricky to force the belligerents in the fertility wars into a neat right and left political and cultural spectrum, or for that matter, into a Conservative v Progressive dichotomy. This is because both sides in the fertility wars contain elements, which have, from time to time, been held up as ideals by the right and left, alike. In his 1841 essay The Conservative, Ralph Waldo Emerson elegantly describes the tension between the Conservative and the Reformer;

And so whilst we do not go beyond general statements, it may be safely affirmed of these two metaphysical antagonists [Conservative and Reform], that each is a good half, but an impossible whole. Each exposes the abuses of the other, but in a true society, in a true man, both must combine. Nature does not give the crown of its approbation, namely, beauty, to any action or emblem or actor, but to one which combines both these elements; not to the rock which resists the waves from age to age, nor to the wave which lashes incessantly the rock, but the superior beauty is with the oak which stands with its hundred arms against the storms of a century, and grows every year like a sapling; or the river which ever flowing, yet is found in the same bed from age to age; or, greatest of all, the man who has subsisted for years amid the changes of nature, yet has distanced himself, so that when you remember what he was, and see what he is, you say, what strides! what a disparity is here!

A casual extrapolation of this passage to the fertility wars is that both extremes in the debate are wrong, and that a golden middle is optimal. Like the lukewarm porridge in Goldilocks, fertility should be neither too high nor too low. This argument is well-rehearsed in the debate, but in the current iteration of the fertility wars, the idea of a golden middle ground frays when submitted to closer scrutiny. The middle ground has been abandoned, in favour of extreme positions, responding differently to the empirical fact of an increasingly rapid decline in global fertility. The passage above by Emerson then lends itself to an alternative interpretation. The Conservative and Progressive have within in them the capacity to embody and argue both sides in the fertility wars, and we should understand why and when either pick one in particular.

Take for example the idea that falling birth rates reflect some kind of fundamental malfunction in the values of today’s society. This side of the argument is currently held and defended by the conservative right, but does it have to be? To the extent that this position in its mild form is simply an ode to values that underpin marriage and the nuclear family, it is not clear to me why this should be monopolised by the right. Couldn’t a progressive left cultural and political program support values that promote higher birth rates, marriage rates and family formation? The answer is of course that it could, though not in its current identity-politics and DEI-infested incarnation. Just the same, a right-wing conservative cultural and political program holding individualism above everything else could easily be consistent with low and falling birth rates if that is what individuals want, irrespective of the effects on the collective. Yet, the defence of such feminist individualism is currently led by the left, while the counterpoint idealising women’s role as mothers and as wardens of the home are held down by the Conservative trad-wive movement.

The political battle over immigration as an economic and cultural force is another area where the right and left positions jar with their views in the fertility wars. If the Conservative right is so worried about global de-population and the cultural flaws that it is a symptom of, shouldn’t they be welcoming the mix of western populations with a non-western polity injecting dynamics with their numbers, higher fertility rates or both? One answer here is, as noted above, that the Conservative right is principally about low birth rates of their inside group. When conservatives go on the barricades in favour of rising birth rates, they’re doing so principally with a view of to their own nation and lineages whom they perceive to be in danger of being replaced. This position is consistent with opposition to immigration. But we also see enough prominent Conservative pronatalists invoking the risk of global depopulation to ask whether they have actually thought through their positions on immigration and fertility, and how to reconcile them. How does reversing the rapid decline in global birth rates in the developing world, ostensibly due in part to economic development, remedy or help what is perceived as an embattled and threatened position of incumbent Western politics and culture, if that is indeed what conservatives are worried about?

The contradiction on the left on immigration and the stance on fertility is even more jarring. How can the left defend a charge against pronatalism when the simultaneous defence of immigration, and the dilution of national and cultural identities in the West, in effect expose their own political economies to the very effects that they claim to be protecting it from by adopting a position in favour of low and falling birth rates? How can the left show such disdain and ire against incumbent cultural populations in the West, when it is these group that increasingly exhibit exactly the climate-protecting fertility decisions they purport to support?

The fluidity of positions in the fertility wars along the traditional political spectrum risks reproducing ideas from the darkest corners of human history. The neo-Malthusian argument comes in a right-wing version too, taking form as an unyielding insider-outsider perspective along either a genetic or cultural dimension, or both. National Socialism’s view of the superiority of the Aryan ancestry, and in particular the need for lebensraum for the German people, is one version of this story, grounded in the idea of a superior nation and race. But this insider-outsider argument is not confined to the nation as the unit of analysis. It can exist on multiple levels of group and kin analysis. It is sometimes linked to seemingly objective macro reproduction strategies such as the idea to limit reproduction to the smartest people with the “best genes”, or so-called eugenics. In their most “benevolent” versions, this is the idea that breeding should be managed for the greater good. But seemingly neutral versions of this position exist on a knife’s edge with a steep slope on either of the centre, in which the insiders get to procreate, but the outsiders don’t.

The imminent threat before us, a danger that lurks if we make just a few steps along a wrong path, is that both the left and right version of the neo-Malthusian position wield power to achieve their desired results. This is because the stakes are so high. After all, if we’re at risk of making the planet uninhabitable due to over-population, how else to improve the situation by coercing people to have fewer children, and once you’ve made that step, it is easy to move on to the idea of culling existing populations. The only question then becomes where to start. Left-wing neo-Malthusianism, in its current iteration, naively puts the blame on the West, its decadence and over-consumption, for the rapid deterioration of the global eco-system, climate change and overall planetary ills. This self-flagellating posture ends, in the extreme, with a bizarre Western cultural and economic suicide, something which many prominent conservative writers and commentators worry about.

Such an outcome would certainly be bad enough, lamentable and worthy of significant opposition. But it is just as likely that left-wing self-deprecating environmental anxiety is merely a phase in a transition towards a much more transparent political program in which might is right. The game currently played by some actors on the left will then, in time, sow the seeds for a right-wing neo-Malthusian switch in which those with power crush those without it. How could it be otherwise if the stakes are indeed as high as we are told. If there is no room for everyone, it stands to reason that some form of a contest will be needed to decide who gets to stay. Once this point is reached, a cultural and political singularity emerges in which the difference between left and right is wiped away, leaving only oppression via institutional and collective power of those commanding the institutional apparatus of the state and armed forces. The 20th century show that both right-wing and left-wing ideologies have it within them to spin out of control to produce such outcomes. The fertility wars is but one axis through which this could happen, and soon.

* This essay contains passages, either lifted entirely or slightly re-written, from chapter five in my demographics book project All the references listed above in Cambridge citation can be found by visiting the landing page this project, linked above.

^ The tax semantics are important in this discussion. There is a big difference between a tax or cash benefit for families and a punitive tax on individuals or couples who choose to, or more importantly, who cannot, have children. Think of a punitive tax on childlessness, along the lines of a tax on sugar, alcohol or tobacco consumption. In the case of children, society wants to encourage families having them, while in the case of sugar, alcohol and tobacco, society would like to disincentivise their use. In the latter case, punitive taxation works because people can choose to not consume the substances, or to consume less, given a high cost of their consumption. For children, however, a punitive tax on not having them effectively is impossible to evade for a whole subset of people, couples with fertility issues, infertile individuals, many homosexual couples, individuals who are struggling to find a mate etc. A tax in this instance become, for some, scarlet letter that never washes off, not to mention that it might encourage people to have children simply to avoid a tax, which isn’t ideal either, in many cases. It is unclear whether Mr. Vance would like to impose such a scarlet letter on his political opponents, but it is in any case not good tax policy. It is much more efficient to use tax policy as a positive incentive to have children, which is what countries do, by and large.

^^ But even if we were able to use technology to sever the link between reproduction and the female biology, what would we be left with but women without meaning? In this ultimate result for feminists lies a pyrrhic victory, in which women are reduced to physically weaker versions of the men that they yearn to supplant and better—at least at the biological outset— and in which what a large part of what constitutes being a women in the first place is erased.