Quality vs Quantity

Here’s a point I made in Chicago last year:

Human capital theory, as I understand it (which isn’t much),  seems to assume that differences in human capital are the product of environmental inputs, much of those inputs contributed by parents.  So people think that you can either have a lot of kids, each with low human capital, or a few with high human capital.  To the extent that human capital is a product of genetic factors (quite a lot), this tradeoff does not exist.

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69 Responses to Quality vs Quantity

  1. ursiform says:

    Kinda depends on whether you plan to send the all to college or teach them all to farm and then divide up the family farm between them …

  2. Handle says:

    Well, of course individuals are both ‘human capital’ and ‘human capital factories’ that build other human capital factories. The fact that let the factory part lie idle most of their lives shows other trade-offs, and that they aren’t expected to personally capture the gains from all those future factories they could be building.

  3. jb says:

    Where in Chicago did you make this point? I’m wondering who would need to be told this. And who, if they did need to be told, would listen.

  4. Sandgroper says:

    I see it as more about whether their human capital can be fully realised. Put crudely, it takes a lot of money to send a kid to university to a level that turns her into someone useful, if she has what it takes to become that. How well the kid does when she gets there doesn’t look like it has a lot to do with environmental inputs, but getting her there and paying for her to stay there long enough sure has a lot to do with financial inputs. That was the trade-off I saw with my kid – that if I wanted to be sure that I had the resources to pay for as much education as she wanted and could do something useful with, I needed to limit how many of her that there were.

    I find that idea kind of depressing, though. If we’d had 2 or 3 and they all showed her talent, we’d be struggling financially to fund them all.

    • gcochran9 says:

      I don’t really thinks it takes all that much money. In the US, we’ve re-engineered college so that it costs about 2.5 times more in constant dollars than when I went to school – but I don’t think they learn any more than before. Run colleges as we used to, with far fewer administrators, much heavier teaching loads, fewer courses in elaborate ways of making bayberry candles or hating your parents, and it’d be a good deal more affordable. If we really tried, made full use of televised lectures and the internet, cheaper than that.

      As an individual making decisions in the actual world we live in, any really talented kid has a pretty good chance of finding scholarships/aid that greatly reduce the cost. Of course that doesn’t make it cheap on a societal level.

      If you think that only the Ivy league will do, it takes money, but then you’re making a mistake.

      • Jim says:

        Also if we ran colleges that way it would become apparent that many of the students there are mostly just wasting their time or maybe having a good time and wasting other people’s time and money.

      • Patrick Boyle says:

        My perspective on college expenses is no doubt warped and cruel. I went to a very expensive graduate school but I didn’t have to take out any of these soul crushing student loans I hear about on TV or the Web. The school paid me not the other way around. They paid my tuition, they paid me to be a TA. They set me up with various foundations so I could get fellowships. I made more money in grad school than I had at my previous full time job.

        So my attitude is that if you have to pay for schooling you must not be a very good student or you are taking self indulgent courses. I’m sure I’m too harsh but that’s how I feel.

        My second wife had student loans but she took the ultimate in self indulgent coursework. She went to the conservatory to become an opera singer. But in fact if you have a really good voice someone will pay you to study. The billionaires are eager to be the patron of the next Pavarotti. Again if no one is willing to pay, you probably aren’t good enough.

        • Alex says:

          “So my attitude is that if you have to pay for schooling you must not be a very good student or you are taking self indulgent courses. I’m sure I’m too harsh but that’s how I feel.”

          It depends on what you are doing. PhDs are (almost?) always fully funded with TA or RA positions.

          On the other hand, undergraduate educations are never paid and rarely free. Law and medicine students are also not paid salaries.

          I think that PhD students are paid because the university sees it as a way of increasing the prestige of the school, whereas masters and professional degrees are seen as revenue-oriented programs.

      • J says:

        I could not agree more. There are so many scholarships out there, so many generous people willing to underwrite a promising young chap, that anybody who wants can study and get a valuable degree. Germany and other countries will pay to young people to fill their empty universities. I have four daughters, put aside a large sum to finance their studies, they never touched the money and completed their degrees with lots of savings (from the Army, scholarships, teaching underprivileged students, prizes for excellence, etc.).

    • L says:

      Having 2 or 3 kids and sending them to a state school is feasible. They would likely have to take out some loans, but the cost will be somewhat offset by them getting more financial aid due to your income supporting more kids. My mom and dad are working class people, but they managed to send all three kids to college, my siblings to top state universities and me to local state u. If your kids are bright, they will be fine financially, there is scholarships available, needs based financial aids and also they will likely finish earlier than 4 years like both my siblings did.


  5. East hunter says:

    I wasn’t aware there was such a thing as human capital theory. I am guessing the Cochran school is that there is an difference of a factor greater than 1 in terms of individual capabilities or externalities as you move up or down each standard deviation.

  6. JayMan says:

    Readers see this post:

    The Son Becomes The Father | JayMan’s Blog

    …which is precisely on this point. Variation in parental input from one family to the next makes absolutely no difference in any economically relevant outcome. So the supposed trade off between quality and quantity is complete hokum.

    For that matter, see also:

    IQ and Birth Order Effects: Real? No | JayMan’s Blog

  7. efalken says:

    I think many parents think of ‘quality’ not merely of their children’s fitness, but their enjoyment of their children. There’s diminishing marginal returns to one’s pair-bond with children.

    In the 80’s there was this ‘quality time’ myth: the idea that it didn’t matter how much time you spent with children as long as it was ‘quality time. Yet there is a quantum of quantity needed for quality pair bonding (nonlinear for sure, but it’s there); ie, there’s a trade-off.

  8. Jus' Sayin'... says:

    If one is a highly-gifted parent (say in terms of a genetic predisposition towards high IQ, long time horizon, low internalized discount rate) one will be raising one’s children to compete in the labor market against the children of other highly-gifted parents. One’s children may start with a relative advantage over most other children but not an advantage over the children they will eventually be competing against. To maximize their competetive advantage in this more limited market gifted parents must make large investments in child-improving activities, e.g., private schools, training in cultural activities like music and dance, camps offering the opportunity to make socially useful connections, and advanced education. These investments are expensive and therefore limit the number of children one can invest in. An even more important and critical constraint is parental time devoted to each child, every bit as important in raising gifted children with a competetive edge as is education.

    On the other hand, if one is an ungifted parent, one’s children are likely to be ungifted too. In this case alrge investments in education are unlikely to improve the chances of one’s children within the labor markets in which they are likely to compete. Raising such children requires relatively little investment and therefore the marginal costs of bearing and raising additional children is low.

    Really interesting cases for study would be how gifted parents of ungifted children invest in these children and how ungifted parents of gifted children invest. A large sample for the former study (created by regression to the mean) would be the parental investment strategies of first-generation highly succesfulblacks in the US.

    • JayMan says:

      That’s the belief. Turns out that’s all horseshit in terms of effect, though.

      “Really interesting cases for study would be how gifted parents of ungifted children invest in these children and how ungifted parents of gifted children invest.”

      I suppose. But see my comment above. It’s probably not necessary.

      • pyrrhus says:

        Yes, the research shows that any parenting effects are transient….Henry Morton Stanley, for example, was an orphan who grew up under extremely harsh circumstances, yet he accomplished a lot.

        • Larry, San Francisco says:

          My cousin grew up in a Jewish orphanage in Chicago. I went with him to his 30th year reunion (this was in the 1970’s). I was always impressed that he been an accomplished arranger and trombone player and then became a successful architect with that background. However, that was not anomalous, the orphanage’s alumni list would have made a small liberal arts college proud. A number had were well-off small business owners whiles others became doctors, attorneys, CPAs and other professions as well. Maybe the derelicts didn’t show up for the reunion but the level of success of these ex-orphans had surprised me.

    • This analysis presupposes competition for revenue as the point of human capital. I guess it’s fine if all you want to do is maximize the money your kids make per capita. But a country full of smart, hardworking people without diplomas from private school will generate goods and services just as well as one full of people who went to the right school. Probably better – they aren’t wasting their time struggling to climb to the top of the heap.

      • L says:

        It’s probably even more important to have the right credentials and high parental investment in the US considering the blue collar work force is predominantly Hispanic in many areas. I would gauge the Hispanic iq in the US as somewhere in the 80s and low 90s. Needless to say, it would be a miserable existence for someone with iq north of 100 to be thrown into that, in addition to the language and cultural differences.

  9. Whyvert says:

    So people think that you can either have a lot of kids, each with low human capital, or a few with high human capital.

    The old time Ashkenazi didn’t think this. They had lots of kids and their human capital turned out high enough thankyou..

    • JayMan says:

      Perhaps this was true in the past, when childhood mortality was near 50% (defined as not making it to adulthood). Adaptations to past environments take a while to adjust to present environments.

    • gcochran9 says:

      yes, and today, they’re mostly believers in environmentalism, probably more than any other group you could name.

      • John Hostetler says:

        A People’s acts show their true beliefs far better than their words.

        • magusjanus says:

          I go back and forth as to whether jews (and smart white progs for that matter) REALLY believe in the environmentalist/nurturist crap they spout, or if you had a real talk to them one on one theyd reveal what they really think i.e. forbidden thoughts.

          I just can’t tell. I personally know of cases of “true believers”, but I get the feeling that for every one fanatically dedicated to the egalitarian/it’s all nurture hypothesis there are many cynics who say on thing and act/think another.

          • Jim says:

            But to what extent does it matter what “they really believe”? Policy tends to be set by offcial ideology even if nobody “really” believes it.

          • Anonymous says:

            I think it’s a mistake to assume it’s one or the other. Most people really do believe that group differences come down entirely to culture and environment — they aren’t lying when they say it, they’re just glossing over certain things they may have observed or conceptualized that might complicate the picture. People use one framework when describing their “scientific” understanding of the world, and other frameworks when doing other things, and you have to pay a fair amount of attention to an issue before you start trying to resolve conflicts.

          • Jim says:

            Yes, what it comes down to is that verbal assertions on ideological issues are often not really propositional. They only seem propositional. So it’s pointless to respond to them with logical or empirical arguments. People who say that genetics has absolutely no effect on human intelligence or behavior ( and there are people who say this in a completely straightforward way ) are not enunciating an actual proposition that they really believe in as a propostion. It’s a speech act with no propositional content. It’s not a matter of them lying but responding to their speech act as if it had propositional content is a mistake. It’s like responding to someone who says “How ya doing?” by giving them a detailed account of the current state of your life. “How ya doing?” only seems to be an interrogation. The person saying it doesn’t give a damn how who are actually doing and would be astonished if you actually answered their question.

          • Jim says:

            It’s part of my nature that I tend to interpert what people say rather literally. So when some one makes some self evidentally absurd PC statement I tend to respond with something like “Are you nuts or what?”. It’s as if they had said it was raining and I looked out the window and the weather was bright, dry and sunny. But now I understand that such assertions often have no propositional content. They are speech rituals which do not really reflect any propositional belief so there is no question of someone either lying or even being wrong.

      • Sean II says:

        Middlebrow intellectuals. That’s who believes in the unlimited power of nurture. People in the 115 to 130 IQ zone. Smart enough to be dangerous, but not quite smart enough to be smart.

        The fact that lots of middlebrow intellectuals are Ashkenazim makes sense when you look at their distribution. They produce a lot of people in that range.

      • sprfls says:

        Is this based on any actual evidence? Just because many of the annoying/vocal writers in NYC are Jewish doesn’t mean that Jews at large are any less hereditarian than others.

        Belief in environmentalism is the standard of today and is shared across all classes and ethnicities. If Jews really believed in breeding, they would continue their successful 19th century and earlier marriage practices, instead of having the highest intermarriage rate of any group.

        Lots of people believe the same crap — Jews just write about it more.

        • gcochran9 says:

          Of course they believe in it more. On average.

          • JayMan says:

            I’d love to test an “environmentalism quotient,” and see how different groups fare on that measure.

          • sprfls says:

            In my experience everyone pushes back against hereditarianism equally. Admittedly it’s biased towards my peer group of higher IQ urbanites, but it does cross many ethnicities.

            Perhaps it’s a matter of confusing causality. People look around and see that the successful ones invariably come from cultures that emphasized education and hard work, whether is be Chinese, Indian, Jewish, or Wasp. “Aha! It must be working!” An honest mistake say I. Nagging mothers and demanding fathers produce salient images while the mechanism for alternative explanations is murky and difficult to grasp. This type of scenario could satisfy both my personal experience and your opinion, as you’d expect the groups with the most emphasis on “culture” to be the least hereditarian.

            @JayMan I’d love to see that as well.

          • John Hostetler says:

            You are assuming that the neurology of belief is unilocal, that people only believe what that fluctuating portion of their neocortex responsible for conscious awareness tells them they believe. The hamster in the wheel, in other words.

            But belief is multilocal, and Jews are as adept at doublethink as any group. Very likely they are the most adept at it of all, and that has been a key to their success in those vehicles for brainwashing the proles (mass media) and those for brainwashing the elites (universities)..

            For example, they are quite capable of believing, say, ‘Somalis are good for Minnesota because environmentalism’ with the most active portion of neocortex, while believing ‘Africans cannot adapt to Israel’ in a somewhat more reflexive portion.

        • Sean II says:

          Those inter-marriages may be less inter- than they appear. When a Jewish cardiologist from Harvard marries an Korean cardiologist from Hopkins, the dice that matter are still pretty loaded. Hardly an all-in wager on the power of environment.

          Now when people adopt a baby from someplace where GDP per capita = <$3,000, then I KNOW they're committed to the creed of nurture, in word and deed.

          • sprfls says:

            So by that measure white Americans are the most environmentalist of all?? Adopting third world kids is more related to pathological altruism than to belief in nurture. That said I’d still wager Jews are very high on the list. FWIW I’ve come across three cases of a Jewish family adopting third worlders and I haven’t met that many people. 🙂

          • JayMan says:


            Please stop saying “pathological altruism.”

          • sprfls says:

            Why? It’s an accurate term for a general mentality which permeates the contemporary Western mindset, manifesting itself in different ways. If you have a better term please do share.

          • JayMan says:


            But it’s not an accurate term, for it implies that it’s a disease, something that was never adaptive. But humanitarian altruism (ultimately an extension of reciprocal altruism – just a pro-active kind) was clearly adaptive in the past, or it would never have evolved. “Misfiring altruism” may be more accurate to say.

          • RCB says:

            JayMan –

            As a general point on evolutionary theory, I gotta say: it ain’t so that anything maladaptive now must have been adaptive in the past. Sounds like you’ve been reading too much ev psych.

            For this particular problem (altruism) there is a big literature with lots of models to consider. Based on empirical evidence, the jury is still out, I think.

          • JayMan says:


            “it ain’t so that anything maladaptive now must have been adaptive in the past.”

            I’m pretty sure I didn’t say otherwise.

          • RCB says:

            JayMan –

            Fair enough. I suppose I took your comment to mean that anything reasonably common and maladaptive now must have been adaptive in the past. Replacing “altruism” with “homosexuality” is enough to make me suspicious of this idea. But – I guess I misunderstood you. My apologies.

  10. Patrick Boyle says:

    A few weeks ago you trashed modern psychology. Now you are trashing academic economics. I guess I’ll keeping reading your blog.

  11. “To the extent that human capital is a product of genetic factors (quite a lot), this tradeoff does not exist.”

    Yep. Big secret.

    Of course, in a time when provisioning your offspring was difficult, there genuinely was a tradeoff there, particularly for sons. After all, an undernourished youngster with no hope of paying a dowry is virtually a genetic dead end. In fact, I would bet that this tradeoff still exists to some extent in a few third world countries, where heritabilities are lower than in the West. But even there, genetic factors have a nonzero input on human capital.

    Oh well. The cool thing about knowing things that other people don’t is that, hey, you get to know things that other people don’t!

    • gcochran9 says:

      effectively, nowadays, it IS secret.

      Different in the old days, sure: the typical question was whether there was enough farm land to go around. Usually not, of course.

      This particular piece of info has lots of practical implications, for both individuals and society.

  12. jabowery says:

    The social sciences are, for the most part, running open loop — without empirical testing of causality — due to the difficulty of running controlled experiments testing causal hypotheses in human ecology. For all of the profound impact that the social sciences have on public policy, you’d think scientific ethics would require them to place one policy recommendation above all others: “Sort proponents of social theories into governments that test them.” as that is the only way to achieve anything resembling consent from their human experimental subjects while at the same time achieving control experiments to tease causation from correlation.

    Given the fact that the social sciences have been using public policy to experiment on unwilling human subjects for over a century now, I think it is high time to start targeting social scientists for human rights violations.

  13. Nick Rowe says:

    Human capital theory goes back to Adam Smith (maybe further). Human capital theory says that one of the things that affects a worker’s productivity (and hence wages) is the amount of investment in education and training (“human capital”). It does not say that investment in human capital is the only thing that affects productivity. It does not contradict human capital theory to say that a worker’s productivity also depends on other things, like genes.

    I would be surprised to meet an economist who said that all workers are identical in their abilities except for differences in investment in human capital. There must be some economists like that somewhere, but I don’t remember ever meeting one. We really aren’t that daft (usually). Indeed, one of the big debates in economics is whether university education is best explained by human capital theory (“we go to university to learn useful stuff”), or signalling theory (“we learn nothing useful but prove to potential employers that we have the innate ability to learn stuff and jump through hoops”), or some mixture of the two. We wouldn’t be having this debate if we thought all students had identical innate ability.

    (But part of the confusion comes from the fact that “human capital” is sometimes used to refer to the productivity itself, rather than the cumulative investment in education and training that influences that productivity. This goes back to a very involved debate about capital theory and how to measure “capital” (both human and non-human) that I want to avoid

    If investment in human capital is one of the things that influences productivity, there may or may not be a trade-off between human capital per kid and number of kids. It depends on whether parents (or kids) can borrow to finance that investment. If they can freely borrow, and invest until the marginal rate of return on investment in human capital equals the market rate of interest [economists from Cambridge UK please hold your tongues] then there will be no trade-off. But if parents (or kids) are borrowing-constrained, and so have a fixed stock of resources to invest, there will be a trade-off, for any particular pair of parents.

    • MawBTS says:

      or signalling theory (“we learn nothing useful but prove to potential employers that we have the innate ability to learn stuff and jump through hoops”)

      I wish that was true, because we’d have an easy job of cost-optimizing university. Just sit freshman in a room for four years and give them some pointless, time-consuming job like learning digits of √2 or something. No faculty, professors, etc required.

  14. Hesse Kassel says:

    For fathers there is a quality/quantity trade off. It’s just that it occurs before conception rather than after birth.

  15. John Hostelter says:

    Patrick Cohen – doublethink before our eyes this very week:

  16. indigene says:

    This point is made at some length by Greg Clark, I think in his most recent book.

  17. Dale Force says:

    My father described another possibility: when he graduated high school Bell could hire B-level students (the IQ they needed) out of high school. By the seventies, all the B-level students went to college, so they were hiring college graduates (same exact job, better in 1940; the job went away in the eighties).

  18. Inductivist says:

    For the traits of obesity, alcohol abuse, altruism, and athleticism, the General Social Survey indicates that the average American thinks genes explain 45%, the environment explains 55%, and the Jewish mean is close to average. https://inductivist.blogspot.com/2019/03/data-do-americans-think-genes-or.html

  19. Steven C. says:

    Investing in human beings does improve “human capital” in that you are helping them to achieve their potential (which will differ from one individual to another). Consider the worst-case scenario wherein I kidnap infants with high potential and keep them in solitude, beating them and starving them for decades. How much of their potential would they achieve if they are rescued at the age of 45? If course such investment returns are limited both by the potential of each individual and by the law of diminishing returns. Each additional increment of investment (nutrition, exercise, education, socialization, etc.) results in a smaller improvement than the previous increment until any further improvements are unjustified because the cost of additional inputs exceeds the value of the improved productivity. Thus it has been demonstrated that a classroom size reduction (in primary and secondary schools) from fifty to thirty students brings about a measurable improvement in learning outcomes; a further decrease to eighteen students results in a much smaller improvement even though the relative reduction is the same: 40%. Improvements in input beyond a certain level may, in fact, result in no measurable improvements in productivity at all! Most of the differences in productivity amongst the middle and upper classes are most likely the result of genetic differences.

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