Category: Education

Does the returns to education literature really test the signaling model?

Here is a comment by Matt, and also by ArnoldBryan’s response argues that the returns to education tests consider “ability bias” but not “signaling.”  For a lot of the tests that is a distinction without a difference, and indeed you can see this on the first two pages of Angrist and Krueger, which discuss “omitted variables that are correlated with educational attainment and with earnings capacity.”  The tests still discriminate against the signaling model, even if signaling and ability bias differ in other regards.  In a nutshell, artificially or randomly elevated workers fare better in the longer run than the signaling model predicts.

Here’s a parable to illustrate.  Imagine a market situation with wages and different education levels observed for two classes of workers — call the locale Honduras.  Now compare that to another setting — Nicaragua — where education is handed out on some subsidized, randomized basis.  In the latter case some of the low ability group will be induced to get more schooling, and the pool of the educated will contain more low ability individuals in Nicaragua, compared to Honduras.

Now measure the long term earnings and compare.

If the signaling model is correct, the average long-term wage rates of return for the subsidized/elevated group in Nicaragua will be noticeably below the average wage rates of return of the educated group from the separating equilibrium in Honduras.  After all, the subsidy-elevated group adds many more “low ability individuals” to the Nicaraguan mix of the educated than one would find in Honduras.  According to the signaling model, in Nicaragua eventually the lower skill level of the elevated group will be discovered and their wage rates of return won’t stay so high forever.

But the wage rates of return for the elevated groups do not plummet back to earth and generally they are robust over time.  That measures the real learning which went on in school, or so it would seem.  Education is good for more than getting a good first job offer right off the bat.

The modern liberal interpretation (which may or may not be true) is that these poor people were waiting for a helping hand up the ladder, and then they took good advantage of it when it came.  And if the elevated group in Nicaragua has higher long-term wage rates of return than the educated Hondurans (a result which does sometimes pop up in the data), that is because their lower initial margin of education made them an especially potent investment.

The actual tests are more complicated than this, and I use the country names to make the example easy to follow, not out of verisimilitude.  But this example is one way to see some of the intuitions behind why the data do not treat the signaling model so kindly.

One empirical implication is that crude OLS measures of the return to education are much better than they may at first appear.  These results are also one reason why most modern labor economists might object to the arguments of Charles Murray.

Here is a recent Brookings piece on the return to education, I have not had time to go through it.

More on the returns to education

First, apologies to Arnold, I missed his post when traveling and so he does discuss natural experiments, contrary to my previous claim about EconLog bloggers.  That said, I’m not so happy with his analysis.  He’s taking a few of the papers he sees as the weakest and he explains why they are weak.  I would rather he dissects the strongest pieces and compares them to the strongest pieces, using natural experiments, showing very low rates of return to education.  The Joshua Angrist papers (often with Alan Krueger) for instance are quite sophisticated and do not run afoul of Arnold’s objections.  In works such as this (later versions seem to be gated), Angrist and Krueger perform exactly the natural experiment which Arnold requests and they find high (marginal) returns to education.  Or see this piece by Card.

Here is Bryan’s response to my post.  Focus on his #2, which is the crux of the matter:.  He cites the signaling motives for education and concludes: “Here, the evidence Tyler cites is simply irrelevant.”  This is simply not true and indeed these papers are obsessed with distinguishing learning effects from preexisting human capital differences.  That is what these papers are, so to speak.  In that context, “ability bias” in the estimates doesn’t seem to be very large, see for instance the Angrist or Card pieces linked to above.  This paper surveys some of the “adjusting for ability bias” literature; it is considered quite “pessimistic” (allows for a good deal of signaling, in Caplan’s terminology) and still it finds a positive five percent a year real productivity gain from an extra year of schooling.

What’s striking about the work surveyed by Card is how many different methods are used and how consistent their results are.  You can knock down any one of them (“are identical twins really identical?, etc.), but at the end of the day which are the pieces — using natural or field experiments — standing on the other side of the scale?  The Card results are also consistent with theory, namely that models which emphasize signaling imply large unrealized gains from trade; it’s not that hard for an employer to administer an implicit IQ test as Google and Microsoft do all the time.  As a separate (and here undocumented) point, I would argue the Angrist and Card results are consistent with the bulk of results from sociological and anthropological investigations.

There really does seem to be a professional consensus.  Maybe it’s wrong, and/or dominated by biased pro-education specialists, but I’m not seeing very strong arguments against it.  For the time being at least, I don’t see that there is much anywhere else to go with one’s beliefs.  If Arnold or Bryan (or David) suggests a good paper with a natural experiment showing a low marginal ROR for education, I am happy to read the paper and report back and compare it to the preponderance of evidence on the other side.

The real puzzle is how large measured marginal returns to education are consistent with the continuing observed failures of the American educational system.  Why does the low-hanging fruit persist or is it low-hanging at all?  The traditional liberal view is that further educational subsidies are needed, but a possible alternative is that some people simply do not wish to step across to the other side of the divide to a “better life,” at least as defined by middle class values and income statistics.  Or is there some other hypothesis?  Whichever way you cut it, a big improvement in this area does not seem about to happen and arguably we are moving in the opposite direction.  Whatever gains are there “in the data,” we don’t seem able or willing to capture them.

Natural experiments and the return to schooling

Cowen’s First Law: There is a literature on everything.

Responding to queries from Kling and Caplan and Henderson, let us turn the microphone over to Andrew Leigh and Chris Ryan:

How much do returns to education differ across different natural experiment methods? To test this, we estimate the rate of return to schooling in Australia using two different instruments for schooling: month of birth and changes in compulsory schooling laws. With annual pre-tax income as our measure of income, we find that the naıve ordinary least squares (OLS) returns to an additional year of schooling is 13%. The month of birth IV approach gives an 8% rate of return to schooling, while using changes in compulsory schooling laws as an IV produces a 12% rate of return. We then compare our results with a third natural experiment: studies of Australian twins that have been conducted by other researchers. While these studies have tended to estimate a lower return to education than ours, we believe that this is primarily due to the better measurement of income and schooling in our data set. Australian twins studies are consistent with our findings insofar as they find little evidence of ability bias in the OLS rate of return to schooling. Together, the estimates suggest that between one-tenth and two-fifths of the OLS return to schooling is due to ability bias. The rate of return to education in Australia, corrected for ability bias, is around 10%, which is similar to the rate in Britain, Canada, the Netherlands, Norway and the United States.

There are many other papers in this genre, such as by Joshua Angrist, and they yield broadly similar results.  Here is an Esther Duflo paper on Indonesia.  There is an excellent David Card survey on the causal returns to education, from 1999, but more recent results have shown the same.  Card’s conclusion:

Consistent with earlier surveys of the literature, I conclude that the average (or average marginal) return to education is not much below the estimate that emerges from a standard human capital earnings function fit by OLS. Evidence from the latest studies of identical twins suggests a small upward “ability” bias – on the order of 10%. A consistent finding among studies using instrumental variables based on institutional changes in the education system is that the estimated returns to schooling are 20-40% above the corresponding OLS estimates.

That last sentence is because the marginal student is especially in need of education.  The view that education is mostly about signaling is inconsistent with the established consensus on the returns to schooling and yet the writers at EconLog do not respond to this literature or, as far as I can tell, even acknowledge it.

Here is one of my earlier posts on education.  Here is my theory of (some) education.

The culture that is Sweden

Director Lotta Rajalin notes that Egalia places a special emphasis on fostering an environment tolerant of gay, lesbian, bisexual and transgender people. From a bookcase, she pulls out a story about two male giraffes who are sad to be childless — until they come across an abandoned crocodile egg.

That’s a preschool, for children from ages one to six.  The school does everything possible to obliterate traditional gender roles, including a refusal to use the words “him” and “her” (that is, their Swedish equivalents).

…she says that there’s a long waiting list for admission to Egalia, and that only one couple has pulled a child out of the school.

Jukka Korpi, 44, says he and his wife chose Egalia “to give our children all the possibilities based on who they are and not on their gender.”

There is even a markets in everything angle:

To even things out, many preschools have hired “gender pedagogues” to help staff identify language and behavior that risk reinforcing stereotypes.

For the pointer I thank Daniel Lippman.

The unwrapped saltine cracker

Every now and then I give informal talks on how the economics job market operates.  I tell the listeners that they are like an “unwrapped saltine cracker.”  They are wasting assets, to borrow a phrase from options pricing theory.  If a day goes by and they did not accomplish something important, they decline in value.  For most candidates, holding steady is not a viable strategy.  You need either publications or some stellar letters from credible writers, preferably both.  (At the very top level, publications at the job market stage are less important because it is expected they will come and the recommendations are trusted more.)

Unwrap a saltine cracker, let it sit for months, and then try to eat it.  Will you even try?

Shimon Peres on Foreign Aid

Shimon Peres gave a press conference for a small group of bloggers. He was very impressive. When asked about foreign aid, specifically foreign aid to some Arab regimes he had this to say (again a paraphrase from my notes, the clever lines are his, the order may have changed somewhat and this is incomplete).

Look, the West can’t help everyone and the regimes would be insulted if we tried. But they don’t need our help. The greatest poverty in our time has been in China and India. Did these countries reduce poverty because of our help? No. They did it themselves.

Giving is problematic. We take money from poor people in rich countries and give it to rich people in poor countries. Aid sometimes creates corruption.

And suppose we gave people computers. Would computers help? No. There is no technology without civilization, civilization is the carriage of technology. It is a matter of institutions. If a country discriminates against women, for example, no computers will help. Do you know who are the greatest opponents of democracy in the Middle East? The husbands. As long as husbands discriminate against their wives the husbands will support the dictators.

Now, however, there is a young generation who are realizing that the glory is within. The glory [of civilization] it is within their power to grasp.

Peres was also great on science, a question I asked. More on that later.

In other news Dr. Ruth criticized social media, “I like to touch my friends.”

Anadolu University

It’s in Eskisehir, central Anatolia, a long way from home.  And yet the campus looks remarkably like George Mason University.  It has about the same number of students, the same kind of suburban feel, the same kinds of sculptures and fountains scattered around campus, the buildings use steps in a similar way, the cars are parked in similar configurations, there is similar signage, and there are related styles of architecture for the buildings.  Here are some photos.  All in all, it is quite unheimlich.

Both schools have women wearing Islamic head scarves, slightly more here.  The Anadolu campus was designed by an economist, unlike George Mason, and the school is a leader in distance education.

I would describe Eskisehir as the Curitiba of Turkey.  I am told it used to be much worse.

Here is a good recent piece on Eskisehir.

Bryan Caplan vs. Amy Chua debate

Here I am, sitting on a bench in downtown Budapest, reading the Guardian, when on p.20 I see a published debate between Bryan Caplan and Amy Chua.  If I have one wish, it is that Chua would put her anecdotal points in the form of a statistical argument.  Which assumption behind the twin adoption studies is she rejecting?  Or where are those studies engaged in too much aggregation?  I suspect she will never tell us.  Coming back to the hotel room, I now find Bryan’s commentary on the debate.  The two have very different senses of humor, and I bet she wouldn’t think that Bryan’s jokes are funny either.

“It is too soon to tell” — the real story China fact of the day

The impact of the French Revolution? “Too early to say.”

Thus did Zhou Enlai – in responding to questions in the early 1970s about the popular revolt in France almost two centuries earlier – buttress China’s reputation as a far-thinking, patient civilisation.

The former premier’s answer has become a frequently deployed cliché, used as evidence of the sage Chinese ability to think long-term – in contrast to impatient westerners.

The trouble is that Zhou was not referring to the 1789 storming of the Bastille in a discussion with Richard Nixon during the late US president’s pioneering China visit. Zhou’s answer related to events only three years earlier – the 1968 students’ riots in Paris, according to Nixon’s interpreter at the time.

How so?

At a seminar in Washington to mark the publication of Henry Kissinger’s book, On China, Chas Freeman, a retired foreign service officer, sought to correct the long-standing error.

“I distinctly remember the exchange. There was a mis­understanding that was too delicious to invite correction,” said Mr Freeman.

He said Zhou had been confused when asked about the French Revolution and the Paris Commune. “But these were exactly the kinds of terms used by the students to describe what they were up to in 1968 and that is how Zhou understood them.”

But will this revelation diminish the use of this story?  Dare I say it is too soon to tell?  By the way:

The oft-quoted Chinese curse, “May you live in interesting times”, does not exist in China itself, scholars say.

The furor over the new British college

Read all about it.  Excerpt:

Current London students also ­pro­tested that New College students would be allowed to use publicly funded facilities such as the main University of London ­Senate House Library in ­Bloomsbury.

As the anger grew, Dawkins distanced himself from the launch, while David Latchman, master of Birkbeck, released a statement making clear that Grayling had resigned from his post to lead New College.

Meanwhile, questions were raised about investors in the venture, which will be one-third owned by academics, with much of the rest of the money coming from wealthy individuals, including a manager at a Swiss private equity firm.

Addendum: Tim Worstall sends along this useful link.

The new British university model?

Well, it’s certainly star-studded. A new private university in London, devoted to the humanities, will have the philosopher and public intellectual A.C. Grayling as its “master.” Richard Dawkins will teach evolutionary biology, Niall Ferguson economic history, Steven Pinker psychology, and Ronald Dworkin the philosophy of law.

Christopher Shea has more.  Daniel Davies notes correctly that few if any of these illustrious names will be resigning their normal academic posts.  That is the real innovation of this business model.  Why not rent illustrious names rather than paying the whole set of fixed costs?  Then hire excellent teachers — mostly not top researchers — to provide most of the actual instruction.  If say Dawkins teaches an intensive two-week course, that is perhaps more than a student would see of him anywhere else, while benefits of certification and affiliation remain in play.  I predict this has a good chance of succeeding, and since the illustrious lecturers hold equity shares in the venture, their incentive is to talk it up.  It doesn’t have to outcompete Harvard, it simply has to draw international interest from students/families who cannot get into Harvard or who do not wish to donate the required $$.

The Global War on Drugs has Failed

The global war on drugs has failed, with devastating consequences for individuals and societies around the world.

…End the criminalization, marginalization and stigmatization of people who use drugs but who do no harm to others. Challenge rather than reinforce common misconceptions about drug markets, drug use and drug dependence.

…This recommendation applies especially to cannabis, but we also encourage other experiments in decriminalization and legal regulation that can accomplish these objectives and provide models for others.

…Break the taboo on debate and reform. The time for action is now.

  • Asma Jahangir, human rights activist, former UN Special Rapporteur on Arbitrary, Extrajudicial and Summary Executions, Pakistan
  • Carlos Fuentes, writer and public intellectual, Mexico
  • César Gaviria, former President of Colombia
  • Ernesto Zedillo, former President of Mexico
  • Fernando Henrique Cardoso, former President of Brazil (chair)
  • George Papandreou, Prime Minister of Greece
  • George P. Shultz, former Secretary of State, United States (honorary chair)
  • Javier Solana, former European Union High Representative for the Common Foreign and Security Policy, Spain
  • John Whitehead, banker and civil servant, chair of the World Trade Center Memorial Foundation, United States
  • Kofi Annan, former Secretary General of the United Nations, Ghana
  • Louise Arbour, former UN High Commissioner for Human Rights, President of the International Crisis Group, Canada
  • Maria Cattaui, Petroplus Holdings Board member, former Secretary-General of the International Chamber of Commerce, Switzerland
  • Mario Vargas Llosa, writer and public intellectual, Peru
  • Marion Caspers-Merk, former State Secretary at the German Federal Ministry of Health
  • Michel Kazatchkine, executive director of the Global Fund to Fight AIDS, Tuberculosis and Malaria, France
  • Paul Volcker, former Chairman of the United States Federal Reserve and of the Economic Recovery Board
  • Richard Branson, entrepreneur, advocate for social causes, founder of the Virgin Group, co-founder of The Elders, United Kingdom
  • Ruth Dreifuss, former President of Switzerland and Minister of Home Affairs
  • Thorvald Stoltenberg, former Minister of Foreign Affairs and UN High Commissioner for Refugees, Norway

The report of The Global Commission on Drug Policy is very strongly worded and the commissioners are so stellar it will be difficult to ignore.

All Watched Over By Machines of Loving Grace

All Watched Over By Machines of Loving Grace, is a hallucinatory BBC documentary that hyperwarps across continents and through time to draw shadowy connections between Ayn Rand, Silicon Valley, the “rise of the machines”, anarchism, the financial crisis and the Monica Lewinsky scandal. (Need, I add and much more!?) Incongruous images and a surreal soundtrack give it a Lynchian feel. Not your usual documentary. Evaluated as a whole, it’s madness but delicious madness.  Here is the first episode.

http://youtu.be/Uz2j3BhL47c

FYI, especially interesting in the first episode is Loren Carpenter’s Pong experiment.  You can read more about that here.