Why do women earn less than men? Evidence from train and bus operators

Even in a unionized environment, where work tasks are similar, hourly wages are identical, and tenure dictates promotions, female workers earn $0.89 on the male-worker dollar (weekly earnings). We use confidential administrative data on bus and train operators from the Massachusetts Bay Transportation Authority (MBTA) to show that the weekly earnings gap can be explained entirely by the workplace choices that women and men make. Women value time and flexibility more than men. Women take more unpaid time off using the Family Medical Leave Act (FMLA) and work fewer overtime hours than men. Men and women plan to work similar overtime hours when they are scheduled three months in advance, but men actually work nearly 50% more overtime hours than women. Women with dependents value time away from work more than do men with dependents. When selecting work schedules, women try to avoid weekend, holiday, and split shifts more than men. To avoid unfavorable work times, women prioritize their schedules over route safety and select routes with a higher probability of accidents. Women are less likely than men to game the scheduling system by trading off work hours at regular wages for overtime hours at premium wages. Conditional on seniority, which dictates choice sets, the weekly earnings gap can be explained entirely by differences in operator choices of hours, schedules, and routes.

That is the Harvard job market paper of Valentin Bolotnyy, co-authored with Natalia Emanuel.


Lesbians earn more than straight women. This is referred to as the "lesbian premium". That proves the gender wage gap is a myth and is actually a motherhood gap.

It is a gay premium, not a lesbian premium, as this is true for gay men as well. Now we need to troll some massive data sets to compare lesbian to gay male earnings.


Jan, thanks for that. I was not up on the latest research.

The so-called gender wage gap is a trumped up issue that is used by the left to pump up the low information voters so that they will vote for free stuff.

Besides the weekly earnings you should take into consideration the life-time wealth accumulation of men and women.


Probably only because the accumulation of preference differences in spending, saving, and earning between sexes over a lifetime would result in a massive gender disparity in wealth outcomes.

Which naturally would imply that society is horrendously biased against women.

Of course, from a certain perspective, dying with wealth is a bit of a failure, isn't the real privilege spending it all and then dying right on time?

A difference in outcomes doesn't necessarily imply bias or inequity. If I like to spend more and save less, I'll end up with less wealth, but that's purely because I chose to use my money on other things. Different people have different preferences and will get different outcomes as a result. That's just basic. On the flip side, if I work more and have less free time, am I suffering from a free time inequity in society? No.

"Of course, from a certain perspective, dying with wealth is a bit of a failure, isn't the real privilege spending it all and then dying right on time?"

From another perspective, dying having spent a lot more time with friends and family might well be worth having less in the bank when you retire. For others, not so perhaps, which is why if things are the result of individual choices matter. (Yes, there's some societal influences on individual choices and gender roles, but one should be skeptical of massive coercive efforts in the name of identical gender roles, especially if done concurrently with massive efforts to encourage, e.g., breastfeeding.)

From another perspective, 90+% of workplace fatalities are men (in dangerous jobs like logging, fishing, etc.; police and fire fighting work is comparatively not so bad), and women live longer.

Most of the gap is in women with children. In the case of married couples, much of that is specialization within the relationship and the assets and wealth are shared. A problem if one partner feels like the burdens are unfair, but otherwise not so much.

This paper is as devastating as the Uber paper on the gender gap. The union contract appears to act very much like the Uber algorithm in removing all discretion by management over rosters, wages and promotion

I had thought that the wage gap debate had largely moved to whether women's preferences are, in some sense, their own, or whether they are distorted by unnecessary expectations placed on them.

It's not a settled question. Lots of people are still claiming that some of the gap is due to discrimination.

The research evidence is not completely conclusive, because discrimination is impossible to measure in many cases. Many studies find that some portion of the gap is not explained by any measured factor, and then infer that this is discrimination.

Over 25 years ago I read that discrimination might account for as much as 5% of the gap.

Expectations of whom? Do the men work extra hours because they want to our because they are expected to?

I suspect that this difference won't last long. Not because women work longer or harder but because young men won't. That has been my experience.

Not because women work longer or harder but because young men won't. That has been my experience.

You'll notice that the propensity of the young to contract marriages underwent a sudden and unexpected decline in the last 20 years, to the point where the number of people who will (one might project) never marry has increased from 5% of each cohort to about 30%. There are aspects of the contemporary dynamic between young men and young women which are...demotivating.

Given economists clearly teach procreation is a bad thing, it's amazing any women go against what they are taught and have kids.

Trump stated the message clearly in his opposition to birth right citizenship.

Being born a citizen in the US puts a massive burden on US government's and on US businesses. No person born in the US is an asset, but instead a big liability.

Trump is saying only the people he would select as citizens should have the right to impose millions of dollars in burdens on the US.

Note, he wants to revoke citizenship of people who have been considered citizens for decades, and who have had children considered citizens by everyone.

Ironically, he doesn't seem to want to go after members of his own family who violated his own standards. His grandfather committed a crime so bad he was stripped of citizenship, and then this criminal came to the US, to be a burden on the US economy, taking from the US government to get rich. And then engaging in chain migration to put even greater burdens on the US.

Economists place a high value on self replicating robots which would replace workers, not require pay, not require government education, not require government keeping food cheap to free, not require medical care, or costly old age care, not require prisons.

Economists tell women that having children is something to be punished with higher personal costs and lower pay for doing the same job as men with fewer errors, but more limits on when or how.

Women are taught by economists, that taking care of children, and family, is bad for the economy.

Trump merely states more bluntly what economists teach. Non-workers are a huge burden. Consumers are a huge burden if they are limited by their wages, or can't work. Babies and children are bad for the economy, very bad because they are always taking, always a burden dependent on government and workers. Worse than zero.

Non-workers are those that sit on the couch. Stay at home parents are _NOT_ non-workers. Teaching a young child is an investment in future productivity and obviously the better the parent is at this, the more future benefit for society. Unfortunately this delayed production doesn't work well for modern economists and politicians who are always looking at the latest numbers to ensure their re-election.

More like the fact that women in hetero relationships do way more housework than men do, even when both people work full time jobs. Or that child-rearing is still considered women's work.

I certainly had not gotten the impression that discussions about the gender wage gap had made anywhere near that amount of progress or achieved that degree of sophistication outside of a fairly rarified world of economist.

In fact, I haven't gotten the impression that the discussion had moved past the idea that women make $0.70 for every dollar a man makes and that the causes are entirely unjust.

I would welcome any links to mainstream discussions that appear to reflect that progress that you indicate.

I'm trying to post links to two Freak ics episodes, but I don't think the comment system allows me to post links.

It's the episodes "The True Story of the Gender Wage Gap" and "What Can Uber Teach Us About the Gender Pay Gap?"

Vox has done quite a bit of reporting on this. I'm not sure about links but the Weeds whitepaper of the week section on their Tuesday podcasts have reported many, many studies that show a strong motherhood penalty.


Well, a lot of the economically illiterate get big stages:

Discrimination starts at home.

Discrimination of unlike things and association of like things are the two sides of intelligence. A society that doesn't discriminate is a stupid society.

I feel like we have such a weird conversation about this.

Like I work in a field that's mostly women, and like yes it's true that no one like puts a gun to their head and forces them to stay home with the sick kid. But social arrangements are such that they end up doing that more often than men and like it's a shitty double penalty of having to really be there for the household for horrible things and getting to be professionally penalized for it.

Like maybe it is all just preferences but with what time use surveys show about household work and time off usage it seems like choice and preference is pretty loosely used around all of these.

Point taken but why is it their employers’ responsibly to improve this for them? If we say it is, then really what we’re asking for is equal pay for lesser work.

Think about it from another perspective - say you are a single person who has chosen not to have children and you’re working for a company that employs mostly working mothers who work 40 hours per week in addition to all the household work they do. Would it be fair for the company to demand that you do 60 hours of work per week (for equal pay) to make up for the household work you don’t have to do?

I’m a childless school teacher and I do get added responsibilities about every other year to cover for a colleague on maternity leave. It’s kind of annoying but fine.

I think like normatively, men should be more involved in parental responsibilities. In seven years teaching I’ve had less than ten conferences with dads and met with every one of my students families. My coworkers are surprised to hear I cook and do laundry on a regular basis.

Like normatively the equality we ended on was something like if you act like a man in the bussiness world we will treat you like a man. Men who really want to spend time with their children are fucked by this stupid system that was just bolted on to the silent partner model of traditional arrangements as are women who really want to have success in bussiness and a family.

By the same token, kids have to eat and wear clothing. Someone needs to pay for that too. It's almost like having a kid costs money. Mom takes time off of work, Dad needs to work more to pay for it. Just a division of labor.

Like that works fine provided that's the arrangements you prefer. My wife and I would both prefer to have the opposite roles and it is constantly clear to us that we're not following expectations. If we were to have children and I wanted to take the amount of paid time off that we give lady teachers it wouldn't be controversial at least.

If you want an even division of labor or a reverse one you will have to be comfortable swimming upstream to get it. It's not formal discrimination but it's asinine and unpleasant.

Agreed that you should be able to switch the roles. But expect the same loss of salary, and acknowledge it was a choice, not discrimination.

I feel like it is. Like you've created a way to do it in a way that technically skates being illegal discrimination but by like devaluing family you've created a way to legally discriminate against people who have strong caregiving responsibilities and because of the social norms we all inherited over millenia that's mostly women who are impacted.

Sounds like you’re just mansplaining to me - check your privilege!

"devaluing family"
What does one expect from a corporate-state system but that? Get rid of corporate personhood and dismantle the power of the government such that family and community can make a comeback.

That won't fix the social pressures with regards to expectations and roles but that can come with time through other efforts.


There is no “system” holding people down. People can and do run their family and work lives however they see fit.

People who spend more time on work tend to make more money. People who spend more time on family tend to benefit in other ways. Different people make all sorts of different decisions based on their own values. Nobody is fucked. Nobody just inherently deserves to have the best of all worlds.

If you want to spend more time with children, you can, you'll just pay for it in the same kind of opportunity cost that women pay.

This kind "Have it all" for women attitude is endemic to the whole mainstream media presentation of these issues though. The general thrust is always that women should never have to change their choices or preferences under any conditions; they should just get given more money or more help and protection in every circumstance, if their choices ever have a relative downside of putting them at more risk or financial drawbacks relative to men.

If you point out inequalities that favor women, such as a widening chasm of childlessness for men (http://sciencenordic.com/quarter-norwegian-men-never-father-children), doubtless a consequence of choices, then there's no real interest in softening the blow of those choices to them.

Well my workplace doesn't offer anything close to the kind of paternity benefits they do maternity ones.

But I mean normatively why should their be any drawbacks to taking care of a family. Like this should be what companies expect everyone to spend a pretty high number of hours a week doing regardless of your gender.

Companies do expect it. It doesn’t mean they shouldn’t pay more compensation to the person who puts in more hours and creates more value. Why is it their responsibility to subsidize your family life?

That said, I more or less agree with you that bureaucracy favoring traditional gender roles is a problem. The solution is not to create more rules that favor fathers. It’s to reduce the bureaucracy.

Well, everyone doesn't. People differ in their family structures, and it seems a bit wrong to redistribute from people who already lack that structure to people who have one, which competes for time with work, but offers them care and support in other ways. For example, lower mortality risk factors in older adulthood - https://phys.org/news/2016-08-relationships-family-members-friends-decrease.html. Extra years of life (not dying) is already a pretty significant benefit.

I don't have kids, but I have 2 dogs. Should I be able to take afternoons off to take them on walks without 'penalty' in the workplace? What if it's just my World of Warcraft character I want to spend my afternoons with? Everyone thinks the things they value deserve special consideration, but really it's just your choice to have a family, and it's no more or less valid than my choice to have dogs, or someone else's choice to have video games. Those choices come with trade-offs; not "penalties".

Yeah but your dogs and your WoW character aren't going to be paying taxes to fund my or anyone else's Social Security and Medicare. Ergo, I have no interest in ensuring that you have adequate time to nurse their health. You actually do have an interest in ensuring that there are healthy, capable workers in the next generation to pay for your old ass.

This. While it aint fair, it's required for a healthy debt-based society. When in doubt about the reason behind some law, ask yourself, what would bankers want?

For me this is where the use of the word "Like" became obtrusive enough to stand out in all the rest of your posts. Please cut back.

I can’t believe the decline of the language has reached the point that the ubiquitous filler word “like” is now appearing in writing and not just speech. And in the writing of a schoolteacher, no less.

I'm glad I was not alone in noticing it.

Give him a break: he can fluently use humanities jargon like "normatively."

Maybe he came to the wrong conclusion for a job market paper.

I once worked a job where I tried to be the primary one staying home with the sick kid. I was fired after about a year for a lack of commitment and my wife left me. I don't know if this proves anything but I consider how much actual choice men have in "choosing" to work more hours vs. having their spouses work those hours so they can care for their loved ones at home.

Same kind of story here -- I was the one taking care of my son for the first two years of his life while his mother did a corporate job, and she got rid of me.

I think that husbands have to make 150% of what their wives make, in order to give the woman the feeling that if she decided to stay at home instead of "working" she'd have significantly more income flowing into her home (his income) than she would have if she supported herself with her job. If the man doesn't make 150% what she makes, there's no incentive for her to get/stay married.

So, as long as there's no freedom of association in the USA (including freedom not to hire people for whatever reason, which would instantly result in a massive drop in employment of women) there oughtta be a law that employers can't pay female employees more than 67% of what they pay males for the same job.

But such a law could only be put into effect by a military dictatorship, and a military dictatorship could just as easily restore freedom of association, which would be far better.

which would instantly result in a massive drop in employment of women)

It wouldn't. Women were a quarter of the formal sector non-agricultural workforce in 1930 and 1/3 in 1957. The employment-to-population ratio hasn't changed much during the postwar period (it has varied between 0.55 and 0.64, with a mild upward trend between 1945 and 1990) while the nature of work has changed in ways more suitable for female employees (with the increase in the ratio of service employees to industrial employees). What's changed in that time is that you have a higher propensity to enter the labor market among married women balancing a higher propensity to exit on the part of the elderly, with some modest changes among youth (more time devoted to higher education, less to working) and those in late middle age (a corps on disability pensions not present in 1957). You're only going to see a 'massive drop' in (1) they're zero-marginal-product workers or (2) they can be readily replaced with automation or (3) they can be readily replaced by persuading late-middle-aged men to postpone retirement.

"higher propensity to enter the labor market" is due to men not being able to make at least 150% of what a woman makes, which is due to the Progressive boot stomping on freedom of association.

Again, the rebalancing of the labor market antedated any federal legislation on such matters by more than three decades.

I don’t follow this at all. Even if he makes only, say, 75% of what she makes, her financial incentive to stay married is that her family has 175% of the income that they would if she were a single mother. Plus, presumably the husband contributes at least somewhat to reducing her household work load.

The ranks of divorcees are filled with women who fancied they could do better. They usually learn the hard way that they couldn't. See Elizabeth Gilbert , whose first husband (the father of her children) has a profession, a history of philanthropic work, and hair. Her second husband was a Brazilian dude who needed a green card, bald, elderly, and shorter than she was (they're now divorced, and she earned it).

your analysis in earlier comments is highly engaging, but EG is childless, and famously so.

This guy chose the most easily-answered question of all time, and gave the obvious answer(s) that everyone already knows, but is terrified to put in writing.

I don't know whether to idolize him, or to tell him he needs to change his name now if he ever wants to get a job.

Of course the sane way to frame this is that women are simultaneously responsible for mandatory unpaid labor -- caring for dependents -- which compromises their availability to drive the bus.

Surely there must be a good Libertarian solution for this dilemma?

Like, "Don't have kids without thinking about who's going to take care of them, and what impact that may have on your life?"

Yes: Don't Have Kids. That's a great idea!

Crazy, completely unrelated aside: you know how someday it will be immoral for humans to drive cars, because networked algorithms will be able to do it so much better? Does that mean that someday it will be immoral for humans to raise their own children, because...

I'm not sure that 'immoral' currently has meaning. If it's not illegal (and not actively sought) or does not have any intense, clear, and present AND LOCAL social stigma/ threat, then why not? If you're willing to do the time, do the crime.

What about - kids cost money? If you like money more than kids, don't have kids?

"Women value time and flexibility over men" is an interesting and somewhat convenient interpretation of these findings. Is it really their utility? Or do women simply face more external constraints on their time and flexibility than men? The author can't make this distinction with these data, but his continued reference to valuation indicates a strong prior.

Also, "women take more unpaid time off using the Family Medical Leave Act" is a hilarious way to describe what is mostly childbirth and informal caregiving duties. I think I'll design a "Congrats on your FMLA!" card for my pregnant friends.

“Is it really their utility? Or do women simply face more external constraints on their time and flexibility than men?“

It’s not a relevant distinction unless those external constraints are coming from their employers. If I’m constrained from working to some degree by having a child, it’s fine to call working fewer hours my preference (as opposed to my employer’s preference) regardless of whether I really wish my wife would do more childcare or not.

We may as well ask “is it really men’s preference to work more hours or is it because of outside financial constraints?” It doesn’t matter in this context.

What is "this context" precisely? And by relevant, I assume you mean theoretically relevant because distinguishing active choices from binding constraints in a study about the gender wage gap (or any matter concerning humanity) is at least a little relevant. To start, think about the policy implications; or lack thereof. If this is simply women valuing their time and flexibility and men wanting to work more overtime, then we can just carry on with the status quo.

I understand why we have to assume away nuance in our approach; but why must we forget it in our interpretation?

Everyone really “prefers” to work fewer hours. But many people (especially men) choose to work more hours because they value money even more than their time. It’s not useful to determine how much of this value is just natural love of money vs need of money due to outside demands - it’s obvious that all of it comes from outside demands to some degree.

From the other angle, everyone “prefers” to make more money, but many people (especially women) choose to work fewer hours because their marginal time is more valuable than their marginal earnings. How much of this value is natural love of free time vs outside demands on their time? I’m sure the vast majority of it comes from outside demands.

The paper didn’t make the distinction because it’s obvious that outside demands are the main reason for the preference, and the real context here is the evaluation of whether employers discriminate based on gender, not the exploration of what those outside demands are.

Also, I fail to see what the policy implications might be - what are the policy implications of proving the already known fact that women on average have more constraints on their time due to family/household work?

This reminds me of a lawsuit I once did some consulting on. A prison was forced to change its rules so that male guards could only guard males (there were allegations of sexual abuse of female prisoners by male guards and this was part of the settlement.) *Both* male guards and female guards sued: male guards sued because of the loss of overtime opportunities and female guards sued because of the increase in overtime forced on them.

This strikes me as an intentionally disingenuous article, little different than saying 'more ambitious people get paid more'. duh. At least it would be interesting if we accept the idea that a certain type of personality attracts promotion or opportunity, all else being equal. So, that we could at least peruse the notion that there is more to a job position than the strict skill set 'bubble', as if we were in school and an indifferent teacher were grading each student without knowing anything about the work except that which was dropped anonymously on their desk - which, is of course, the kind of world that 'equality by outcome' people want anyway.

The well worn statistics often cited to show a wage-gap are more simplistic than this so comparatively this article appears sincere to me, anyway.

This question is like you ask people "Why do women can feed their kids or have a baby?" I am not against equality but we have to change our view about discrimination, our policy must change about our physical abilities, sexes, ... then we feel calm whenever we consider more for men and other place for women

One thing this job market paper seems to be missing is an actual paper. I see an abstract but no link to a download.

Am I missing it somewhere?

Seems a lot of conversation here for just an abstract.

This whole "gender wage gap" appears to be a measurement error. The ways in which the things being measured were grouped changed the apparent information. More information is making excellent progress and the "problem" is going away.

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