Picture two skilled workers up for the same team-leader job. They have the same qualifications and the same years on the job. One works full-time and has no one depending on them at home. The other works part-time and cares for young children or an aging parent. Who does the boss pick?
A team of researchers set out to untangle a version of this question that has puzzled labor economists and sociologists for years. Women remain underrepresented in leadership roles across wealthy countries, even as they have caught up with, and often surpassed, men in education. Is that gap driven by employers who simply prefer men for the corner office? Or is something else going on?
Writing in Research in Social Stratification and Mobility, Caroline Wehner of the Federal Institute for Vocational Education and Training in Bonn, along with Paula Protsch and Andries de Grip, offers evidence that the disadvantage women face has less to do with their gender itself and more to do with two things that are unevenly distributed between men and women: working part-time and shouldering care responsibilities.
The problem with real-world data
Here is the puzzle the researchers wanted to solve. In the real world, women more often work part-time and carry more of the caregiving load at home than men. That makes it hard to separate cause from correlation. If a woman gets passed over for a promotion, is it because she is a woman, because she works reduced hours, because she has kids at home, or some tangled combination of all three?
Ordinary workplace data cannot easily pull these threads apart, because the traits tend to travel together. There is also the matter of who even applies. In a company staffed mostly by men, few women may put themselves forward for a leadership role in the first place, which muddies any comparison.
To get around this, the authors used a method called a factorial survey experiment. Instead of studying actual promotion outcomes, they built fictional employee profiles and asked real employers to rate how likely they would be to promote each one. Because the researchers controlled every detail of these profiles, they could vary one trait at a time and watch how employers responded.
How the experiment worked
The study focused on Germany, where nearly half the working population holds an intermediate vocational qualification. These skilled workers often work in teams led by an experienced colleague, so promoting one of them into a team-leader role is a common, everyday decision rather than a rare event.
The experiment was folded into a large national survey of German employers. The researchers ended up with 1,373 people who genuinely had a say in promotion decisions at their organizations, including owners, CEOs, and human resources managers. Each person reviewed up to seven short profiles of hypothetical employees and rated, on a scale from 0 to 100 percent, how likely they would be to promote that person into a management role for 20 hours a week. In total, the analysis covered 9,511 of these promotion judgments.
Every profile described a skilled worker with a vocational degree who had been at the company for at least three years. What changed from profile to profile were eight traits, assigned at random. These included the worker’s gender, whether they worked part-time or full-time, and whether they had care obligations, meaning they looked after children or relatives in need of care. The profiles also varied in age, professional and social skills, whether the person lived with a partner, and how big a pay raise they wanted for taking on the new role.
Because the traits were assigned randomly, the researchers could treat the results as evidence of cause and effect within these simulated decisions, rather than just associations. They analyzed the data using a statistical approach that splits the promotion decision into two stages: first, whether an employee is even considered eligible, and second, how likely they are to be promoted once they clear that bar.
Gender barely moved the needle
The first finding cuts against a common assumption. Employers did not favor men. If anything, women had a slightly higher predicted promotion probability, 41.1 percent versus 40.2 percent for men. That gap is small but statistically real.
The picture shifted a bit depending on the makeup of the workforce. In organizations staffed mostly by women, female candidates had a meaningful edge, with a promotion probability about 2.9 percentage points higher than men. Men did not enjoy a matching advantage in male-dominated workplaces. The authors read this as a sign that women are not seen as a poor fit for leadership in general, and may even be preferred where most of the staff are women.
Part-time work and caregiving carried real penalties
The larger story lies elsewhere. Working part-time lowered a candidate’s promotion probability by about 4.4 percentage points compared with working full-time. Having care obligations knocked off another 2.5 percentage points compared with having none. These penalties applied to men and women alike.
Stack the traits together and the effect grows. An employee who worked full-time with no care duties had a promotion probability of 44.3 percent. One who worked part-time and had care obligations sat at just 37.4 percent. The two-stage analysis showed that both traits hurt at each step: such workers were both less likely to be judged eligible for promotion and less likely to be chosen even when they cleared that first hurdle.
The researchers connect this to what economist Claudia Goldin has called “greedy work,” the idea that the most rewarded jobs demand near-total availability. Reduced hours or obligations outside work signal a departure from the “ideal worker” who is assumed to be fully dedicated to the job.
There was one gender-specific twist. Care obligations dragged down women’s promotion chances more sharply than men’s. Women without care duties held a slight edge over comparable men, but that edge vanished once care obligations entered the picture. Among candidates with care responsibilities, men and women were rated about the same. The authors suggest one possible reason: caregiving may carry a different meaning when attached to a woman, with employers assuming she devotes more time and energy to it.
Family-friendly policies did not close the gap
The team also tested whether company work-family policies, such as help finding childcare, flexible hours, or the option to work from home, softened the caregiving penalty. They did not. In companies with such policies, workers with care obligations still trailed those without by roughly the same 2.5 percentage points seen elsewhere. Having the policies on the books did not appear to change how employers weighed a candidate’s care duties.
What it suggests, and what to keep in mind
Putting the pieces together, the authors argue that the lower promotion rates women experience in practice stem largely from the uneven distribution of part-time work and caregiving, rather than from bias against women as such. Because women disproportionately carry these two burdens, penalties that fall on any worker with those traits end up landing hardest on women.
That framing carries a sobering implication the authors themselves raise. If couples split paid work and family duties more equally, both partners might end up sharing the career penalty rather than escaping it, since the disadvantage attaches to the reduced hours and care load themselves.
A few caveats are worth keeping in mind. The study measured stated intentions in hypothetical scenarios, not actual promotions, though the authors note that this method tends to reduce the pressure to give socially acceptable answers. The slight pro-women result could reflect awareness of societal pressure to promote women, and the researchers call for more work to confirm how robust it is. The measure of work-family policies was also broad, lumping many different programs into a single yes-or-no question, so future research may need to examine specific policies one by one.
