Saturday, June 28, 2008

Higher education and human capital

What good is higher education? The conventional view is that, in addition to producing a well-informed citizenry, it builds important human capital and raises national productivity. But what is the evidence for these assertions? In policy debates we are typically presented with faulty logic: workers in desirable, high value-added jobs (e.g., at Google or Biogen) tend to have lots of education. Therefore, if we want Americans to have such jobs we had better expand access to higher education. The counter argument, that returns to society as a whole from education diminish as access increases beyond the cognitive elite, is given below by a well-known curmudgeon and psychometric realist:

Brutal, just brutal: ...There is no magic point at which a genuine college-level education becomes an option, but anything below an IQ of 110 is problematic. If you want to do well, you should have an IQ of 115 or higher. Put another way, it makes sense for only about 15% of the population, 25% if one stretches it, to get a college education. And yet more than 45% of recent high school graduates enroll in four-year colleges. Adjust that percentage to account for high-school dropouts, and more than 40% of all persons in their late teens are trying to go to a four-year college--enough people to absorb everyone down through an IQ of 104.

Note the claim is not that benefits from higher education are zero for the average student, but merely that they diminish significantly as we expand access. At some point we need to consider whether the marginal cost exceeds the marginal benefit. No amount of schooling will turn an average student into a materials engineer, tax lawyer or derivatives trader.

I'm afraid these kinds of thoughts lurk in the minds of most professors these days -- I've heard them discussed many times. Why can't my students write? Why can't my students do simple math? Does the bottom half of the class really absorb anything from my lectures? Is science just too difficult for some people? If I showed you some of the emails I receive from students in my physics 101 course, you would cry at the lack of mastery of grammar and spelling, let alone physics.

Below I excerpt some depressing results from researchers at Stanford and Yale, which support the sorting and signalling model of higher ed, rather than the human capital building model.

Education and Verbal Ability over Time: Evidence from Three Multi-Time Sources

Nie, Golde and Butler

Abstract: During the 20th century, there was an unprecedented expansion in the level of educational attainment in America. Using three separate measures, this paper investigates whether there was a concurrent increase in verbal ability and skills. Changes in verbal ability in the general population as well as changes in the verbal ability of graduates of different levels of education are investigated. An additional investigation of how changes in the differences between males' and females' educational attainment are associated with changes in differences between their respective verbal abilities follows. The main finding is that there is little evidence that the large increase in educational attainment has resulted in an increase in any of the measures of verbal abilities and skills.

From the paper:

The results from using these three different measures of verbal ability and skills all show the same striking patterns: (1) there is no increase in scores in the overall population over time; (2) as the number of people obtaining a certain level of education increased, the verbal ability of those terminating with that degree has decreased. ...

Comment for the psychometric cognoscenti: where is the Flynn effect here? I see no overall increase in verbal IQ.

See also this less technical exposition:

Nie and Golde: ...Our initial hypothesis was that if amount of schooling causally affects any outcome, it would be verbal ability. The vast expansion of the American education system over the course of the 20th century served as our test bed. We expected that the huge increase in educational attainment in the U.S. across the decades would be accompanied by a substantial improvement in verbal abilities. To our initial amazement, we found no evidence for such improvement.

We started our investigation by showing that there is, indeed, a strong correlation between education and verbal ability. The data on which our analyses are based came from the General Social Survey, a program of in-person interviews that has been conducted regularly since 1972 by the National Opinion Research Center at the University of Chicago. While the samples were nationally representative, to avoid complications caused by changing demographics and questions about the validity of such tests with minority and immigrant populations, we included only the native-born, white American population 30 to 65 years of age, using information collected over the last 35 years of parallel surveys. (We used only those 30 years or older to ensure that we were dealing only with people who had completed their education; we stopped at age 65, lest we contaminate the analysis by differential mortality rates.)

Education levels and scores on a vocabulary test given to subjects are indeed correlated (see Figure 1). Over the three-plus decades studied, those with more education got better vocabulary scores, and vice versa.

Those results, however, do not necessarily imply that education causes increased verbal ability. If education did increase verbal ability, we would expect increasing levels of education over time to bring about measurably higher levels of verbal ability. During the 20th century, there was an unprecedented expansion in the levels of educational attainment in the U.S. The average American born between 1910 and 1914 received a bit more than 10 years of education. The average American born between 1970 and 1974 received 14 years of education. In 60 years, the "average American" went from being a high school dropout to having two years of college — a remarkable increase. The increase in education is across the board. A person born between 1910 and 1914 who obtained some postgraduate education was in the top 6 percent of his or her cohort in terms of education. By the 1970s, nearly 16 percent of the birth cohort had some postgraduate education. The percentage of college graduates or beyond has almost quadrupled over the same period, from just over 10 percent to almost 40 percent.

But, as Figure 2 shows, even though education has increased considerably through the decades, and even though education is correlated with verbal ability, verbal ability has stayed practically constant over time. The lack of change in the average vocabulary score of Americans, despite the large increase in the population's average years of schooling, is an intriguing finding. ...


Anonymous said...

At least in the US, the reason so many people go to college is that we don't develop enough skills in high school to compete for jobs that will offer us a middle class standard of living. A college degree is the new high school diploma. For most college majors, there is nothing "higher" about the education. The intellectual requirements are not significantly beyond that of high school. It would be nice if we could renormalize and get at least the first two years of course work at, say, a quality state school, to be taught in high schools. Employers would have to recognize the increased quality of the high school diploma, and award jobs accordingly.

Odds that this will happen? Slim to none. I'm interested to hear any good ideas for this problem.

Steve Hsu said...

I think Murray (the curmudgeon I quote at the beginning) is saying something stronger -- that the fraction of the population that can really master essential college material (basic math -- say, algebra and ability to interpret graphs, solid reading and writing skills, basic science) is relatively small - like 25% of the population. If he is right, then making high school more rigorous will only speed up the education of the smart fraction but not help the others. Over half of the population just won't be able to master the material, whether they get it in high school or in a dumbed-down college curriculum. (In most places we still have some remnant of tracking, so the bright students do often take AP courses in high school these days. It's the others I am worried about.)

It sounds too brutal to be true, but from my teaching experience he isn't obviously wrong. Students at UO have SATs around 1150-1200 and decent high school GPAs (well over 3.0 on average), but, like students at other public universities, often can't spell, write grammatically, multiply fractions reliably, or calculate the area of a circle without looking up the formula. I've seen all of this first hand, and I'm not talking about the bottom 10% on campus, I'm talking about the lower 30-50%.

Anonymous said...

This all reminds me of a well written piece of commentary in June's Atlantic, regarding the effective necessity of college education for today's high-school graduates:

"The idea that a university education is for everyone is a destructive myth. An instructor at a “college of last resort” explains why."

Steve Hsu said...

Nice article. "Professor X" gives you a feel for what it's like in the trenches. But I don't think he knows enough about psychometrics and the normal distribution to really understand why things are the way they are.

Most professors don't really think about the basic question -- what fraction of the population, even given unlimited educational opportunities, can learn to write coherent, error-free prose? If the fraction is much less than 40%, then many current college students are in for a rough time.


“I can’t believe it,” she said when she received her F. “I was so proud of myself for having written a college paper.”

She most certainly hadn’t written a college paper, and she was a long way from doing so. Yet there she was in college, paying lots of tuition for the privilege of pursuing a degree, which she very likely needed to advance at work. Her deficits don’t make her a bad person or even unintelligent or unusual. Many people cannot write a research paper, and few have to do so in their workaday life. But let’s be frank: she wasn’t working at anything resembling a college level.

Anonymous said...

How much does high school and undergraduate college/university education these days, have more to do with keeping kids and young adults off the streets during the day? (ie. Actual real "education" is not the first priority?)

Everybody knows what happens when there are large numbers of bored kids and/or young adults running around on the streets all day, with nothing to do.

Anonymous said...

I am not convinced that the reason so many people go to college is that they didn't "develop enough skills in high school." I think a great many of them go to college simply because employers use college degrees (and, increasingly, graduate degrees) as a sorting / credentialing process. They probably have the same "skills" when they graduate college as they did when they graduated HS, but now they have that piece of paper that makes them more competitive when seeking employment.

In my field, we won't even consider an applicant who doesn't at least have a master's. Not because the people with the master's have more "skills" than the people with a bachelor's. Simply because we want to cut down on the number of resumes we have to look at.

Anonymous said...

Here in the Netherlands the vast majority of children attend state funded primary schools. The schools can be "regular public", Montessori, Dalton, Jena Plan, Catholic, Muslim, Christian,etc. The parents choose which kind of an education they would like their child to have. Children are tested each year according to a state run standardized test and in the final year of primary school they receive the "end test". Results of this test combined with the "advice" of the child's teacher are the criteria for entering any number of secondary schools. Those secondary schools range from the technical schools to the professional schools and to the more academically focused schools such as classical Gymnasium. (There is a wide range and I'm sure that I'm not aware of all that is available.) It's generally the students who have attained a high enough score on the "end test" and who "demonstrate a great motivation to learn" who go to an academic secondary school and eventually to University.

It's a tough system. There is not a lot of room for parents to push their kids through the system as it is often difficult to get any information on just how well one's child is performing. No homework and not much material from school comes home. As a result, many highly educated parents are devastated to find that their child has not gotten the "advice" to move on to a competitive secondary school. When confronted a teacher would not hesitate to explain that the child is merely "average".

There are a lot of problems with the current Dutch system and I would never recommend it to anyone serious about their child's education. There seem to be very low standards in the primary schools, there is no accommodation for different learning styles and to me it seems terribly harsh that a child's academic career and earning potential can perhaps be decided before the age of 12. On the other hand, I've noticed that most people seem quite content with their career or "place in society". I suppose it's quite relaxing for someone who is a less than average student to know that he or she can go to school and receive training to get a suitable job; and that there is no pressure really to do anything else but that.

I wonder if a more varied Middle School and High School system would benefit U.S. students. There is a stigma associated with "shop" classes in the U.S. Could some restructuring help us lose that stigma? Would we have better trained, happier skilled workers?

Anonymous said...

(reply to Moeder)

> No homework and not much material from school comes home.

There's been an anti-homework sentiment here for quite awhile, with younger teachers typically "caving in" to the sentiment and assigning very little to no homework. I've heard of some teachers making homework as optional, or only assigning homework to the students whose parents signed a consent form demanding regular homework. To compound the problem, parents still expect their kids to be geniuses while doing very little to no homework.

Some people may argue how much homework helps or hinders in the learning process.

The catch-22 in this situation is that the teachers who insist on assigning regular homework, may not get hired the next school year. School boards and younger "inexperienced" principals typically only want to hire teachers who are relatively "low maintenance". The "high maintenance" old timers who still follow the more "hardline" traditional education methods (ie. discipline, regular homework, etc ...), typically end up eventually leaving the profession with an "early retirement" when nobody wants to hire them anymore.

> There is a stigma associated with "shop" classes in the U.S. Could some restructuring help us lose that stigma?

In town here and nearby cities, they have eliminated almost all of the "shop" classrooms and replaced them with computer labs. The only schools left which still have "shop" courses and classrooms, are the high schools which handle the kids with dyslexia and other mild learning disabilities.

Steve Hsu said...

The Dutch system sounds like a rational one. The US system does have tracking in some places, but it always comes under attack -- here in Eugene, the code words are "equity" and "diversity" :-(

I think one good point about the US system is its flexibility. A student who starts out poorly can still catch up if sufficiently talented and motivated. The junior college system accepts almost anyone, and from there one can transfer to a good public university and, ultimately, even to a graduate program at one of the top universities in the world.

But, we waste a lot of resources because we aren't hard headed enough to apply real filtering. There are majors that really don't add much to our nation's economic human capital, and most of the really mediocre students end up in those majors (or drop out without a degree).

Anonymous said...

> There are majors that really don't add much to our nation's economic human capital, and most of the really mediocre students end up in those majors

Over the years, the two absolute lowest "bottom of the barrel" majors have been consistently education and psychology. (Even majoring in history or political science is considered more respectable). For the education majors, many never even end up in the teaching profession after graduation.

A side effect of education majors being at the "bottom of the barrel", is that the ones who eventually end up in the teaching profession, may not even know very well the subjects they have to teach. Sometimes weird scenarios end up happening, such as a biology teacher being assigned to teach senior year high school physics. (This is exactly what happened when I took senior year high school physics. The teacher assigned was mainly a biology teacher, but who was pushed into teaching senior physics for that school year. This teacher didn't have a good firm grasp of physics, which made the class very confusing).

Unknown said...

The GSS, which is the source for the time trend data, has a 10-item vocabulary test as its measure of verbal ability. SAT verbal peaked decades ago and has been mostly flat, but note that SAT math has increased and is the highest it's ever been. The Flynn effect shows up on tests that are more abstract, e.g. Raven's Progressive Matrices.

Anonymous said...

I think the utter lack of a functional vocational education system in the US is a big reason. Everyone wants their kids to go to college, which is great, and of course they don't all do well.

At least college is still held in high esteem, right? Yes, lots of money is wasted, but the alternative is deemphasizing the importance of college, which leads to deemphasizing the importance of being educated. I'm not sure that's a direction I'd want to go until the current system of advanced placement and academic honors begins to fail to separate the people who are really smart from the people who probably shouldn't be there but thank god they are because their vote counts just as much as mine in the next elections.

Anonymous said...

"Why can't my students write? Why can't my students do simple math? Does the bottom half of the class really absorb anything from my lectures?..." That's pretty much how I felt when I was a TA at Stanford. In fairness, it was mostly premeds in the class.

Anonymous said...

Re: American teachers out of their fields.

I had a visual art teacher for pre-algebra and a failed football coach for AP biology.

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PaulaPNelson said...

You can really see from the diagram that education is important and many people are undergoing this kind of stage. A kid wants to become rich someday or wanted to achieve his/her dream and the only way to achieve this is education. It's an advantageous on your part if you finish education because you will know many important things that would look you professional and be respected.

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