Why are mothers in the developed world are having less kids?
Mothers worldwide are slowly (not rapidly) but persistently having fewer children
In the first three articles, we’ve seen how Shaw’s decomposition reveals two independent crises (Are We Measuring Fertility Wrong?), how economic shocks permanently collapse motherhood rates (Why economic (especially energy) shocks permanently lower fertility rates & total maternal rates (TMR)?), and how America’s inequality temporarily masked the problem through rising CPM (Why Rising Family Size Temporarily Hid America’s Motherhood Decline (1980-2016)). Now we examine the fourth piece: why CPM erodes relentlessly in most developed nations.
Shaw’s data reveals a striking pattern across 33 countries: while Total Maternal Rate (% of women who become mothers)(TMR) shows sharp (even crisp), crisis-driven breaks (all 47 Japanese prefectures simultaneously in 1974, US collapse in 2008), Children per Mother (CPM) declines gradually and continuously regardless of economic conditions. Italy dropped from 2.10 to 2.02 since the 1980s. France fell from 2.40 to 2.28, stable until 2010 then declining. The United Kingdom went from 2.35 to 2.23 since the 1990s. Japan declined from 2.20 to 2.13 over the same period. The United States increased from 2.39 to 2.63, covered in third article.
Shaw describes CPM as showing “remarkably stable” patterns with “tight clustering and limited variability.” Not unchanging, but exhibiting gradual trends rather than crisis-driven shocks. What drives slow, continuous CPM erosion independent of the economic shocks that devastate TMR?
Mario Draghi’s April 2024 admission provides part of the answer: “Especially after the crises, we made a deliberate effort to suppress wage growth to increase external competitiveness.” European governments ensured families couldn’t survive on one income, forcing both parents into full-time work, then watched fertility collapse.
Why Statistical Independence Matters for Policy
Shaw’s finding that TMR and CPM are statistically independent (knowing one tells you nothing about the other) has been missed for decades by policymakers.
Traditional thinking assumed fertility decline is one crisis requiring one solution. But independence shows these are two crises needing different interventions. Economic recovery restores TMR without reversing CPM erosion.
The 2008 Financial Crisis demonstrates this. TMR collapsed sharply, the US going from 76.1% to 69.4%. CPM continued its gradual trend, rising from 2.39 to 2.63. Crisis affects family formation (employment, partnership, confidence) without touching constraints on expansion (time poverty, biology, cumulative burdens).
TMR responds to crisis-sensitive variables: employment stability collapses during recessions, partnership formation freezes during uncertainty, economic confidence crashes during shocks, and marriage market conditions get scarred by instability. CPM responds to crisis-insensitive forces: biological windows narrow continuously with maternal age, time and economic constraints build gradually, work-family compatibility erodes through policy drift, and geographic proximity to support disperses slowly.
Economic crises devastate variables affecting whether people become parents. Mothers with one child contemplating a second are already partnered, employed enough to have afforded the first child, committed to parenthood. Their decision depends on capacity for additional children: biological time remaining, accumulated resources, available time. These erode gradually rather than collapsing suddenly.
The Gap Between Desired and Achieved Fertility
Eva Beaujouan’s 2023 comprehensive analysis documents a critical finding: people aren’t choosing to have fewer children. They’re failing to have the children they want.
Women starting childbearing at age 25 achieve 96% of their desired fertility. By age 30, this drops to 90%. By age 35, women achieve only 75% of what they intended. The gap isn’t about changing preferences. It’s about accumulating constraints that prevent people from reaching goals they hold.
At age 30, women have a 75% chance of conception within one year and 85% achieve a second birth. By age 35, conception chance drops to 66% and only 62% achieve a second birth. The biological window narrows independent of intention.
Beaujouan documents the mechanism: “Fertility delay implies that people are spending a shorter period trying to have children” combined with biological efficiency declining exponentially. Each year of delay doesn’t just postpone fertility. It mathematically reduces maximum achievable family size.
This pattern repeats! The Dutch study captured women’s fertility hesitation centered not on whether they wanted children but on logistics: “impossibility of managing pregnancy while maintaining careers.” Dutch women live in one of Europe’s most generous welfare states yet cited this impossibility even as that welfare state faced cuts. The Netherlands provides an example of gradual policy degradation: childcare subsidies reduced 3% in 2012 (leading to 72,000 fewer children in formal childcare by 2014), healthcare co-payments increased in 2010, public sector wages frozen 2004-2005. These represent selected examples among broader retrenchment trends. The desire exists. The structural capability was being reduced.
The question isn’t “How do we convince people to want more children?” The question is “Why can’t people have the children they already want?”
France: What 40 Years of Success Reveals About Removing Barriers
France maintained CPM of 2.30-2.40 from the 1970s through 2010. Nearly 40 years while Italy and UK declined. This wasn’t accident.
Real wage growth enabled single-income viability. Universal cash transfers scaled with family size. Universal childcare operated 6am-7pm, matching work schedules rather than creating gaps parents had to cover. The 35-hour workweek provided genuine time restoration. Housing policy enabled family proximity to work. Children were integrated into public spaces. Cross-party political commitment was sustained for 58 years.
Lyman Stone’s review documented that cash transfers successfully increase second+ births. France generated 5-10 million additional people over 80 years through sustained investment.
France’s success proves people will have additional children when barriers are removed. This wasn’t about convincing French couples to want larger families. The policies enabled people to reach fertility goals they held.
Then the erosion began. The Socialist government introduced means-testing in 2014. The study showed when benefits were eliminated, women increased work by 4.2 additional hours weekly and men 2.1 hours weekly. This shifted time toward wage labor when benefits no longer covered childcare costs. France’s CPM decline became detectable around 2019, roughly five years after the policy change.
Macron’s presidency (2017-2024) accelerated the shift. France remained OECD’s highest spender (over 57% GDP) without addressing time poverty. Labor “flexibility” meant easier firing, not schedule autonomy. The zero net land development law by 2050 made it illegal to develop land unless existing development was demolished. Nation-wide rent controls proceeded without supply expansion. The result: housing costs eats a higher % of income, geographic dispersion accelerated, and 75-90 minute commutes became normal. Not to mention the burning of YIMBY credibility in France as Macron represents the “centrists”.
CPM fell from 2.30 to 2.28 between 2010 and 2024, and French TFR went from 2.0 to 1.66.
Sustained comprehensive support prevented CPM erosion for four decades by enabling people to achieve their fertility intentions. Policy changes to a previously functional system prevented people from reaching their goals, and what’s worse it seems that nothing was gained because of it..
Taiwan HSR: Remove the Barrier, Fertility Increases Immediately
Taiwan’s 2007 high-speed rail (Yeow Hwee Chua, Pei-Syuan Lin, and Tien Foo Sing) provides the cleanest natural experiment. No cultural campaign. No financial incentives. Just infrastructure removing a logistical barrier.
The HSR connected Taipei’s expensive job market with affordable southern cities, cutting travel time from 4.5 hours to 90 minutes. Couples previously separated by economic necessity could now live together while accessing both Taipei employment and Kaohsiung housing affordability.
The fertility response was immediate and substantial. Couples previously separated showed +6.5% fertility. First births increased 16.2%. Later births rose 6-8%.
This wasn’t about changing preferences. Geographic separation made parenthood difficult. One partner in Taipei for work, the other in Kaohsiung for affordable housing, seeing each other occasionally. Managing one child under these conditions was difficult. Contemplating a second was unrealistic.
The HSR removed the geographic barrier preventing families from having the children they contemplated. Within months, fertility increased.
The Taiwan finding is critical because it proves the constraint is structural, not cultural or preferential. No government campaign told these couples to value family more. No financial incentive changed the economics. Pure infrastructure enabling proximity was sufficient.
For mothers contemplating a second child, grandparent availability often determines feasibility. The HSR reduced Taipei-Kaohsiung from impossible for routine support (4.5 hours) to feasible for weekly help (90 minutes). Grandparents who wanted to help their children raise families could suddenly do so. Infrastructure made it possible.
With one child, couples managed 4.5-hour separation with difficulty, seeing each other weekends. With a second child, that arrangement becomes impossible. Two children of different ages with different needs require coordination that weekend visits can’t provide. The HSR enabled existing fertility intentions.
South Korea’s 2019 study quantified the same pattern. Same municipality residence shows 21.6% higher birth odds. 60-minute commute shows 28% lower odds. 90-minute commute shows 41% lower odds.
Norway: Work Rigidity as Binding Constraint
Norway’s March 2020 lockdown created another unintended natural experiment, triggering a 10% birth rate increase nine months later. Employed women showed +10% fertility while unemployed women showed +0% fertility. Women in rigid occupations showed +15.2% fertility, a 152% stronger effect.
The mechanism reveals the constraint. Unemployed women were home with no fertility increase. They already had time. Employed women gained schedule control and fertility jumped. These weren’t women who suddenly decided they wanted children. These were women constrained by rigid work schedules preventing them from managing additional children.
Women in the most inflexible jobs (teachers, nurses, office workers) showed the strongest responses. These professionals, theoretically best positioned to afford children, were most constrained by work rigidity. The lockdown removed the structural barrier.
Mothers with one child were already employed and managing. The barrier to second child was the incompatibility between rigid work schedules and managing two children. When work rigidity disappeared, these employed mothers (who already had resources, partnerships, and one child) could contemplate additional children.
Norwegian women maintained reduced working hours through 2024, four years after lockdowns. Firms discovered pre-pandemic rigid scheduling was unnecessary. The fertility increase persisted because the barrier removal persisted.
The pattern repeated in Singapore (Senhu Wang and Hao Dong), where hypothetical reduced working hours increased fertility intentions 79% among employed, partnered women. Professionals, theoretically best positioned to afford children, showed the strongest responses. Work rigidity prevented achievement of intentions.
Norway’s experiment isolates work rigidity as a specific constraint on family size people contemplate. The 10% fertility increase when rigid work disappeared reveals how much current work arrangements suppress births people would otherwise have.
The Biological Constraint on Wanted Fertility
Compare a mother in 1980 versus 2020 contemplating a second child. In 1980, single-income families were viable. Father’s wage was sufficient for a family of 3-4, mother’s time was available for childcare. The decision was “Do we want another child?” By 2020, the dual-income trap had closed. Combined wages are barely sufficient for family of 3, both parents’ time is consumed by mandatory 40-hour weeks. The decision became “Can we economically and logistically survive another child?”
The change isn’t about desire. It’s about feasibility.
Denmark and Germany’s unemployment study (Kreyenfeld & Andersson, 2014) reveals how economic constraints affect fertility timing. Less-educated young unemployed women showed 50% higher fertility than employed peers. They had time but needed money. Highly educated unemployed women showed 20% lower fertility. They had money but valued career progression and delayed to establish themselves professionally.
The highly educated delay childbearing for career establishment, then face biological constraints when attempting the larger families they contemplated. They’re forced into smaller families by the interaction between career timing pressures and biological windows.
The study documented childcare matching work schedules. Denmark provided availability from 6am-6pm matching actual work hours, with no benefit cliffs forcing additional work hours. This enabled mothers to have additional children by removing the logistical gap where work requires presence but childcare is unavailable.
But Denmark’s celebrated flexicurity model was eroding through gradual cuts. In 2010, responding to rising unemployment costs, Denmark cut unemployment benefits from four years to two years, one of the most controversial reforms in recent Danish history to the point that they temporarily rolled parts of it back in 2013 because it turned out it wasn’t a good idea to limit benefits in wake of the Great Recession.
The reform required workers to have 52 weeks of employment to regain benefits, doubled from the previous 26 weeks. By 2013, over 30,000 Danes annually ran out of unemployment benefits, compared to only a few thousand previously.
There is a nice and rich research pile on how unemployment benefits protect both income and fertility rates. Considering how others are trying to sell Danish “flexicurity” to their own counties, this doesn’t bold well.
Not to mention, modern partnership patterns compound biological constraints. Increasing numbers experience short childless unions that dissolve before childbearing begins, consuming prime fertility years. In Spain, median age at first stable union rose from 23 to 29. But 40% of these unions dissolve within 5 years if childless. Women re-partner around 32-33, beginning childbearing at ages where second birth probabilities already decline.
These women don’t want smaller families. They wanted stable partnerships earlier, faced instability, and by the time they find stability, biological windows have narrowed. The fertility gap between desired and achieved widens with each delay.
As TMR falls and average age at first birth rises simultaneously, that’s going to lower TFRs. Now adding to the independent downward pressure on CPM, you have women who become mothers later have narrower biological windows for subsequent births regardless of their preferences. Delaying first birth from 25 to 30 reduces maximum achievable family size from 2.5 children to 2.2 children on average. Not because women at 30 want fewer children than women at 25. Because biology constrains achievement of existing fertility intentions.
Draghi’s Wage Suppression and the Dual-Income Trap
Draghi’s admission exposes policy choices: “Our real wages failed to keep pace even with our slow productivity, while US real wages rose 9 percentage points more than wages in the euro area. We pursued a deliberate strategy of trying to lower wage costs relative to each other, and, combined with procyclical fiscal policy, the net effect was only to weaken our own domestic demand and undermine our social model.”
The policy implementation was systematic. In the United Kingdom, real wages fell 8-10% since 2008 and remain 2% lower in 2024 than 2010. LSE research shows UK had worst wage stagnation since records began in the 1860s. Greece cut minimum wage 22% and public sector pay 15% total, while private sector wages fell 12% from 2010 peak. Ireland cut public sector pay 15% average between 2009-2010. Spain cut public employees’ wages 5% and froze retirement benefits while youth unemployment exceeded 50%. Italy’s real wages stagnated for 20 years after abolishing automatic wage indexation in 1992, leaving average salaries 45% below Germany’s.
Wage suppression didn’t change what families wanted. It changed what they could afford. Many couples prefer one parent available for childcare, especially when children are young. Wage suppression made that choice unaffordable. Both parents must work full-time, creating time poverty that prevents additional children couples would otherwise have.
The income-fertility relationship shifted. In the Netherlands (van Wijk, 2024), high-income men are 3.11x more likely to become fathers than low-income men, up from 2.38x in 2008. Among women the ratio is 2.44x, up from 1.63x. Sweden (Kolk, 2021) shows fertility now rises monotonically with lifetime income for men, with childless men earning 40% less lifetime income than fathers of 3+ children.
This isn’t because poor people don’t want children. It’s because wage suppression prevents them from affording the children they contemplate. Wealthy people can still have larger families because they escape the dual-income trap. Everyone else is forced into smaller families than they intend.
Sweden’s pattern is particularly telling. The country embarked on sustained welfare retrenchment from the 1990s through 2010s. A 2020 study documented how Sweden cut social expenses, privatized its pension system, and made significant cuts to unemployment benefits. After two decades of continuous decline in income replacement and rising stringency in qualifying conditions, the country showed decreasing healthcare provision with higher eligibility conditions. Public sector wages were frozen in 2004-2005. Sweden became a dual-earner society as single-income viability eroded through accumulated cuts. Despite maintaining high government spending, Sweden saw the OECD’s fastest-growing inequality measured by percentage change from its previously exceptional equality baseline, with poverty rates rising most among single-adults. Starting from OECD’s lowest inequality, Sweden experienced the steepest relative increase while remaining more equal than most countries.
Even in Sweden, once held up as proof that comprehensive welfare enables fertility, the policy direction moved toward requiring dual employment while making additional children harder to afford through gradual benefit reductions. The 1990s crisis affected Sweden’s universalistic welfare state, weakening it substantially through successive reforms. The impact on families contemplating additional children was clear: the safety net that had enabled risk-taking (having another child) eroded cut by cut, precisely as dual employment became mandatory.
German Job Destruction and Employment Security
German researchers (Chen Luo and Ewa Jarosz) tracked 400 regions across 13 years, finding job destruction reduced fertility 40% more than job creation increased it. Male manufacturing workers faced the strongest effects. When factories closed, birth rates plummeted. When new positions opened, fertility barely budged.
The asymmetry reveals something about security versus opportunity. Couples want economic stability before having additional children. Job creation provides potential income but doesn’t eliminate the uncertainty scarring from previous instability. Job destruction creates immediate constraints mothers feel when contemplating additional children.
These mothers don’t want smaller families. They want economic security sufficient for larger families. Job destruction prevents them from achieving what they contemplated.
Time Theft Through Benefit Cuts
Vanhuysse, Medgyesi, and Gál’s 2023 European study quantifies the burden shift. Parents contribute 2.66 times more total transfers than non-parents: 27% visible in public accounts, 49% invisible family labor, 24% private spending.
Governments combined wage suppression with benefit cuts. A few (more) early examples as governments responded to the Great Recession, we have the United Kingdom, child benefit was withdrawn from families with higher-rate taxpayers from January 2013, and IFS shows families with children lost £2,200/year average from tax and benefit changes since 2010.
Parents didn’t suddenly want to spend less time with children. Benefit cuts required them to work more hours to compensate. Time that would go to caring for additional children gets extracted for wage labor. The intention to parent remains. The time to do so doesn’t.
Nordic Countries: Gradual Erosion Through Accumulated Cuts
Nordic countries maintained higher CPM longer than Southern Europe. Denmark went from 2.40 to 2.20 (slower than Italy’s drop from 2.10 to 2.02). Sweden declined from 2.35 to 2.25 (slower than UK’s fall from 2.35 to 2.23). Norway dropped from 2.50 to 2.30 while maintaining a higher baseline.
Nordic countries show CPM decline roughly half the Southern European rate, around 0.005 annually versus 0.010-0.012. But this slower erosion doesn’t reflect policy stability. Nordic countries have progressively converged toward EU average in social security spending through accumulated cuts. Unemployment benefit schemes experienced significant retrenchment, gradually converging toward the European mean through sustained reduction.
The examples documented above (Denmark’s unemployment benefits from four to two years exhausting 30,000 people annually, Sweden’s welfare cuts producing OECD’s fastest-growing inequality from an exceptionally equal baseline, Netherlands’ childcare subsidy reductions and healthcare co-payment increases) represent selected instances among hundreds of smaller policy changes. Each cut is defended individually as necessary fiscal prudence. Collectively, they’ve transformed systems that once enabled achievement of fertility intentions. The process continues today.
The irony is that these cuts may not save money. When Denmark cut unemployment benefits duration, over 30,000 people annually exhausted benefits and required other support. When Netherlands cut childcare subsidies, 72,000 fewer children attended formal childcare, but this didn’t eliminate the care need or the cost. When healthcare provision was cut while tightening eligibility across Europe, research documented 1.5 million extra people with unmet healthcare needs since the crisis began. The cuts shift costs rather than eliminating them: from public budgets to families, from visible spending to invisible family labor, from preventing problems to managing crises.
Despite retrenchment, Nordic countries maintained some advantages that Southern Europe lost entirely. Wage growth remained more robust than Southern Europe’s collapse. While Draghi admitted deliberate wage suppression across the Eurozone, Nordic currencies (Norway, Sweden) or special arrangements (Denmark) allowed somewhat more independent monetary policy. Single-earner families, while increasingly difficult, remained possible longer as erosion was gradual rather than sudden. Geographic density enabled proximity. Nordic cities, though facing housing cost pressures, avoided the extreme dispersion seen in France or Spain. Work culture retained more flexibility than Southern European or Anglo systems despite formal retrenchment.
But even these remaining advantages couldn’t prevent CPM erosion. The biological constraints from delayed childbearing affect all countries. The work-family tensions remain even in better systems. The policy direction (toward retrenchment through accumulated cuts rather than expansion or maintenance) matched the rest of Europe.
The Nordic pattern reveals that comprehensive support from a high baseline slows CPM erosion significantly. The 0.005 annual decline versus 0.010-0.012 in Southern Europe shows policy choices matter. Starting with more support and cutting it gradually produces slower erosion than starting with less and cutting aggressively. But both produce erosion. Nordic countries are converging toward the same 2.0-2.2 CPM equilibrium as the rest of Europe. The process is gradual (cut by cut), ongoing (still happening), and questionable economically (shifting rather than eliminating costs). Without policy reversal, they’ll reach the same destination as Southern Europe, just more slowly.
Physical Exclusion and Coordination Problems
The dual-income trap creates multiplicative constraint. Parents must be in child-free spaces 40+ hours weekly, requiring childcare. Childcare closes at 5pm while work demands presence until 6-7pm.
With one child, parents cobble together solutions through grandparent coverage, leaving work early, or after-school programs. With two children, these solutions often don’t scale. Grandparents struggle managing two different-aged children. After-school programs have different pickup times. Career impact of leaving early every day becomes severe.
Modern economies systematically exclude children from adult spaces. Restaurants discourage families, offices prohibit children, shops lack accommodation, and public transport resists strollers. Parents who would prefer occasionally integrating children into adult activities can’t. They’re forced into constant childcare arrangements that become increasingly difficult for multiple children.
Iceland’s Third Birth Surge Among Educated Mothers
Iceland (Arnalds et al., 2025) showed third births jumped 38% among tertiary-educated women during lockdowns. One woman explained: “I thought it rather nice to be pregnant and not be able to do anything when you cannot do anything anyway.”
This specifically boosted progression from second to third child among wealthy mothers. The pandemic temporarily removed barriers by eliminating commutes and reducing obligations. Mothers who had contemplated third children but couldn’t manage them suddenly could.
The Iceland finding confirms the Norway pattern: work rigidity and time poverty prevent births women contemplate. When those barriers temporarily lifted, fertility increased specifically among women who had been constrained. The selectivity reinforces that wealthy mothers already had the resources and contemplated additional children. They needed the barriers removed.
Why CPM Erosion Differs From TMR Collapse
TMR policies could theoretically help at any age through improving marriage markets or reducing economic instability. CPM interventions face biological deadlines and escalating constraints that limit when barriers can be removed.
The first to second child transition (ages 27-35) occurs while biological windows remain relatively wide but requires immediate barrier removal. The second to third child transition (ages 32-40) happens as biological windows narrow significantly and requires removing multiple barriers simultaneously.
Shaw’s data reveals countries converging toward CPM of 2.0-2.2 regardless of starting point. This isn’t an equilibrium of desired fertility. It’s an equilibrium of achievable fertility under current barriers. Italy has reached 2.02. France sits at 2.28, declining toward 2.2 as barriers accumulate. Nordic countries range from 2.20-2.30, showing slow decline toward the same equilibrium.
The convergence suggests current barriers constrain achievement to around 2.0-2.2 even when desired fertility is higher. Beaujouan’s data confirms this: women starting childbearing at 25 achieve 96% of desired fertility. By age 35, only 75%. The gap widens as barriers accumulate.
What Policy Changes Would Remove Barriers
France between 2010-2024 proved that re-imposing barriers reduces fertility among people whose intentions haven’t changed. Taiwan HSR proved removing logistical barriers immediately increases fertility—16.2% for first births. Norway proved removing work rigidity immediately increases fertility—10% overall, 15.2% in rigid occupations.
The lesson: people want more children than they’re having. Remove the barriers, and fertility responds immediately.
Slowing erosion requires ending wage suppression that forces both parents into full-time work. Default flexibility rather than rigidity. Remote work rights eliminating commute time. Earlier childbearing support when fertility windows are widest. Housing policy that allows building where families can afford proximity to work and extended family.
The Nordic evidence shows comprehensive support slowed erosion to 0.005 annually, roughly half the Southern European rate, despite decades of gradual cuts.
Bottomline
Shaw’s CPM documentation reveals what policymakers have missed: barriers prevent people from having the children they contemplate.
France removed barriers 1970-2010 and CPM stayed stable at 2.30-2.40 for forty years. Then France re-imposed barriers 2010-2024 through means-testing and zero-net-development. CPM eroded to 2.02. Fertility intentions hadn’t changed. Achievement couldn’t keep pace.
The mystery’s solution reveals two parallel crises. During economic shocks, TMR collapses as people cannot enter parenthood. Between shocks, CPM erodes as barriers prevent people from having additional children they contemplate.