What the world's largest study of work hours reveals about how we work

For decades, the assumption held firm in corporate boardrooms and academic circles alike: as countries grow richer, their workers put in fewer hours. The busy factory worker in a developing economy, the story went, gradually gives way to the leisured professional of a wealthy nation.

A sweeping new study by economists Amory Gethin of the World Bank and Emmanuel Saez of UC Berkeley demolishes that tidy narrative — and in doing so, offers HR leaders a more complicated, more honest, and ultimately more useful picture of how work actually behaves across cultures, economies, and generations.

Drawing on labor force surveys from 160 countries and covering 97% of the world's adult population, the paper — titled Global Working Hours — is the most comprehensive accounting of human labor ever assembled. Its findings arrive at a moment when senior people leaders are navigating remote work normalization, talent shortages, generational workforce transitions, and the relentless pressure to extract more from less. The implications deserve careful attention.

The bell curve nobody expected

The headline finding is counterintuitive. Hours worked do not simply fall as economies develop. Instead, they follow a mild bell shape — rising through middle-income development as manufacturing and services expand, then declining in high-income countries. But the overall correlation between national wealth and total hours worked is, in statistical terms, close to zero.

The average employed person on earth works 42 hours per week. Adults globally — employed and not — average 24.5 hours of work per week when you account for those outside the labor force entirely. Men contribute 65% of all hours worked worldwide; women, 35%.

For HR professionals accustomed to thinking about productivity through a purely Western lens, this global baseline reframes the competitive landscape considerably.

The gender story is the real story

Beneath the aggregate stability lies one of the most significant workforce transformations of our time, playing out across every region the researchers examined.

Over the past several decades, prime-age men have been working fewer hours on the job — not because they are dropping out of the workforce, but because they are working shorter hours when they are in it. Prime-age women, meanwhile, have been entering the paid workforce in growing numbers almost everywhere, nearly offsetting men's declining hours hour for hour.

The researchers describe this as a "great gender reshuffling" — a rebalancing of labor market participation that is simultaneously reducing the long hours of working men and drawing more women into paid employment. Crucially, they found this shift is happening faster in today's developing economies than it did historically in now-wealthy nations, possibly reflecting the active promotion of women's economic participation by international institutions.

For talent acquisition and retention leaders, the message is clear: the candidate pool is being fundamentally restructured by gender. Organizations that have not seriously addressed the structural barriers to women's advancement — flexible scheduling, equitable pay, parental leave, sponsorship — are not simply failing on equity grounds. They are failing to compete for a growing share of the available workforce.

Young people are working less. That is not a problem.

The study documents a near-universal decline in working hours among people aged 15 to 19 across all regions over recent decades — a drop largely explained by rising school enrollment. The researchers found that school attendance alone accounts for nearly 70% of the variation in youth work hours across countries.

This finding carries a pointed message for workforce planners concerned about pipeline development: the talent entering organizations tomorrow is more educated than at any point in history. But they are arriving later, with higher expectations, and with less tolerance for the long-hours cultures that older generations normalized.

The generational implication is not merely one of attitude — it is structural. Organizations built around the assumption that entry-level workers will absorb extreme workloads in exchange for future advancement are increasingly misaligned with the workforce they are trying to attract.

The elderly are not following the script

Perhaps the most striking temporal finding concerns older workers. In wealthy countries throughout the mid-20th century, the expansion of public pension systems produced a dramatic withdrawal of older workers from the labor force. The researchers document this clearly in long-run data for the United States, where elderly work hours fell sharply between 1900 and the 1960s.

What is happening today in developing economies is different. Older workers in lower-income countries are not following that same path — largely because the generous pension systems that funded early retirement in richer nations are not being replicated at the same scale or pace.

The implications extend beyond the developing world. In high-income countries, where pension sustainability is under pressure and retirement ages are being revisited, the study's findings on what actually drives elderly work — pension coverage, not economic growth per se — should inform how HR leaders think about phased retirement programs, knowledge transfer, and the genuine desire of many older workers to remain engaged on their own terms.

Taxes, regulations, and the hours you actually work

The paper's most technically ambitious section examines why workers in high-income, high-tax countries work fewer hours than their counterparts in lower-tax economies. The conventional explanation — that higher taxes reduce the incentive to work — turns out to be only part of the answer, and perhaps not even the main part.

When the researchers controlled for formal employment rates and working-hours regulations, the apparent effect of labor taxes on hours worked largely disappeared. The more powerful explanation is structural: high-income countries have developed extensive formal employment sectors governed by regulations covering overtime pay, mandatory leave, maximum weekly hours, and weekend work. It is these regulations — not taxation alone — that drive down intensive work hours.

For multinational HR leaders managing workforces across jurisdictions, this distinction matters enormously. The number of hours your employees work is not primarily a function of how motivated or well-compensated they are. It is substantially determined by the regulatory and institutional environment in which they operate — and by the degree to which your organization operates formally within that environment.

What this means in practice

The researchers are careful to describe their findings as correlational rather than causal. But the patterns they document across 160 countries and more than two decades of time-series data are robust enough to carry real implications for senior HR leaders.

The workforce of the future will be older, more female, more educated at entry, and governed by an increasingly complex patchwork of working-hours regulations. The organizations best positioned to thrive will be those that have moved beyond industrial-era assumptions about hours as a proxy for productivity — and built cultures, policies, and measurement systems that reflect the reality that global labor data now makes impossible to ignore.

The world, it turns out, has always worked in more varied and complex ways than our models assumed. The evidence is now 97% of humanity strong.

Data points worth knowing: what the numbers actually say

• The average employed person worldwide works 42 hours per week — virtually identical to the 40-hour standard written into law in many countries, suggesting the global norm and the legal standard have converged in practice.
   
• When non-employed adults are included, the global average drops to 24.5 hours per week per adult, reflecting how large a share of the world's adult population is outside paid work at any given time.
   
• Men supply 65% of all hours worked globally; women supply 35% — a gap driven almost entirely by employment rates rather than hours worked on the job. Employed women work 37 hours per week compared to 45 for employed men.
   
• Only 48% of women globally are employed, compared to 71% of men — a gap that persists across nearly every income level but narrows significantly in wealthier nations.
   
• Moving from 0% to 100% Muslim or Hindu population share in a country is associated with an 11-hour reduction in weekly hours worked by prime-age women — the single strongest cultural variable in the entire dataset.
   
• Former communist countries show markedly higher female labor participation, a legacy of systems that required equal workforce participation regardless of gender, and the effect persists decades after the fall of communism.
   
• In the poorest countries, at least 10% of workers put in more than 60 hours per week. In rich countries like the US, France, and Germany, fewer than 10% work more than 50 hours — reflecting how formal employment regulation compresses the distribution of hours.
   
• About 11.5% of the world's employed population works exactly 40 hours per week — a striking spike in the data that reflects the power of regulation and social norms to coordinate behavior at scale.
   
• School attendance explains nearly 70% of the cross-country variation in how much teenagers work — far more than GDP per capita alone, which explains only 23%.
   
• Moving from 0% to 100% pension coverage for the elderly is associated with roughly 11 fewer hours of work per week among people aged 60 and above — confirming that retirement is a policy outcome, not simply a natural consequence of aging or wealth.
   
• The US is the only country for which a homogeneous, century-long series of work hours exists covering the full population — and it shows remarkable stability in prime-age work hours from the 1900s to today, with the Great Depression the only major interruption.
   
• China vs. Germany: though employment rates are similar in both countries, prime-age adults in China work roughly 50% more hours per week than their German counterparts — a gap explained almost entirely by differences in working-hours regulations and formal employment structure, not culture or motivation.
   
• The database underlying the study contains surveys of over 470 million individuals across 2,500 surveys conducted since the 1960s, making it by far the largest harmonized labor dataset ever constructed.
   
• In middle-income countries, workers in manufacturing and private services regularly average around 50 hours per week — the highest intensive hours of any development stage, echoing the 19th-century industrial experience of today's wealthy nations.
   
• The rise in female employment and the fall in male working hours have exactly offset each other in many countries over recent decades, producing a deceptive stability in aggregate prime-age hours that masks one of the most significant labor market shifts in modern history.