Video of my Sackler lecture on learning, with Ido Erev

The title of the paper that this will become is "Maximization, Learning and Economic Behavior."



https://www.youtube.com/watch?v=T9cl_aKIHuc
This video is from the colloquium In the Light of Evolution VIII: Darwinian Thinking in the Social Sciences, hosted by the National Academy of Sciences, organized by Brian Skyrms, John Avise and Francisco Ayala, and held January 10-11, 2014 at the Beckman Center in Irvine, CA.

Learning and adaptation in the social sciences: NAS Sackler conference, January 10-11

Ido Erev and I will be presenting a paper  on learning and choice behavior at one of the Sackler Colloquia run by the National Academy of Sciences:

In the Light of Evolution VIII: Darwinian Thinking in the Social Sciences

Organized by Brian Skyrms, John C. Avise and Francisco J. Ayala

January 10-11, 2014 at the Arnold and Mabel Beckman Center in Irvine, CA.

 Overview

Darwinian thinking is now having a major impact in social science, both in the consideration of the consequences of biological and cultural evolution on traditional questions, and in the use of quasi-Darwinian adaptive dynamics in evolutionary game theory. This Darwinian point of view is having a major impact on economics, political science, sociology, anthropology, and demography.

Agenda

I.  Evolution of Social Norms

Bargaining and Fairness, Kenneth Binmore, University College London
Cooperation, Natalia Komarova, University of California, Irvine
Friendship and Natural Selection, James H. Fowler, University of California, San Diego
Reputation and Punishment, Michihiro Kandori, University of Tokyo

II. Social Dynamics

The Replicator Equation and Other Game Dynamics, Ross Cressman, Wilfrid Laurier University
Payoff-Based Learning Dynamics, Alvin Roth, Harvard University
Strategic Learning Dynamics, David K. Levine, Washington University
Cultural Evolution, Marcus W. Feldman, Stanford University

Keynote Address:  Public Goods: Competition, Cooperation, and Spite, Simon A. Levin, Princeton University

III. Special Sciences

Evolutionary Demography, Kenneth W. Wachter, University of California, Berkeley
Folklore of the Elite and Biological Evolution, Barry O’Neill, University of California, Los Angeles
Economics, Ted Bergstrom, University of California, Santa Barbara
Psychology, Dale Purves, Duke-National University of Singapore Graduate Medical School

IV. Applications

Evolutionary Implementation in Mechanism Design, Éva Tardos, Cornell University
Some Dynamics of Signaling, Brian Skyrms, University of California, Irvine
The Rate of Innovation Diffusion in Social Networks, H. Peyton Young, Oxford University
Homophily, Culture, and Coordinating Behaviors, Matthew O. Jackson, Stanford University

Notes on teachers and students from the rabbinical literature

As I get older I appreciate more the bonds between teachers and students. These aren't as recognized in modern literature as are other kinds of bonds, between parents and children, husbands and wives, brothers and sisters... One exception is in the rabbinical literature.

Here's a brief collection of quotes, I'd be glad to know of more.

Rabbi Yitzchok Etshalom Talmud Torah 5:13
13. The students add to the teacher's wisdom and expand his understanding. The sages said: I have learned much wisdom from my teacher, more from my colleagues and the most from my students (BT Ta'anit 7a); and just as a small piece of wood ignites a large one, similarly a small student sharpens the teacher['s mind] until he extracts from him, through his questions, wondrous wisdom.

http://www.torah.org/learning/rambam/talmudtorah/tt5.13.html

alternate translation, from Maimonides, Laws of Torah Study, http://www.panix.com/~jjbaker/MadaTT.html chapt 5:
13) Students add to the wisdom of their Rabbi, and open his heart. The Sages said that they learnt more from their Rabbis than from their friends, but learnt even more from their students. Just as a small candle can light a big one so a student sharpens his Rabbi's wits, by extracting from him his wisdom by means of questions.

Pirkei avot: Chapter 1.1
The Men of the Great Assembly had three sayings:
Be deliberate in judging;
Educate many students;
Make a fence around the Torah.

Pirkei avot: (Chapte 1, 6) Joshua ben Perachyah and Nittai the Arbelite received the Torah from them. Joshua ben Perachyah said: Provide [make] for yourself a teacher and get [acquire] yourself a friend; and judge every man towards merit. http://www.shechem.org/torah/avot.html

Some commentaries have trouble with the first two clauses, and I've seen "get a friend" translated as "find someone to study with." But another way to understand it  (maybe, I'm no Talmud scholar) is that teachers and friends (and students and friends) can intersect and be the same folks...

5.12 12. There are four types of student. One who is quick to understand and quick to forget--his flaw cancels his virtue. One who is slow to understand and slow to forget--his virtue cancels his flaw. One who is quick to understand and slow to forget--his is a good portion. One who is slow to understand and quick to forget--his is a bad portion.

Sanhedren p105, side B: no man envies the accomplishments of his children or his students


"דאמר רב יוסי בר חוני בכל אדם מתקנא חוץ מבנו ותלמידו" "Reb Yossi bar Honi said 'of everyone a man is envious except his son and his student'."
( סנהדרין • קה ב )

*******
update: I should note that another literature/tradition in which bonds between teachers and students are noted is in martial arts .

Update: Charlie Nathanson reminds me of  Perkei Avot chapter 4, verse 12 (https://www.sefaria.org/Pirkei_Avot.4.12

רַבִּי אֶלְעָזָר בֶּן שַׁמּוּעַ אוֹמֵר, יְהִי כְבוֹד תַּלְמִידְךָ חָבִיב עָלֶיךָ כְּשֶׁלְּךָ, וּכְבוֹד חֲבֵרְךָ כְּמוֹרָא רַבְּךָ, וּמוֹרָא רַבְּךָ כְּמוֹרָא שָׁמָיִם:

"Rabbi Elazar ben Shammua said: let the honor of your student be as dear to you as your own, and the honor of your colleague as the reverence for your teacher, and the reverence for your teacher as the reverence of heaven."

Language exchanges

Learning a Language From an Expert, on the Web reports on various communities of language learners who help each other out.
"Livemocha, a Seattle company with $14 million in venture capital financing, mixes a social network with lessons for more than 38 of the world’s more common languages.

"The initial lessons are free, but unlocking some of the additional features requires a fee to Livemocha (starting at $10 for a set of lessons) or an agreement to correct the work of others..."

"MyLanguageExchange.com just maintains lists of people who know certain languages and want to learn others. Anyone can search the database, but only gold members, who pay $24 a year, can send e-mail easily to others."
...
"RhinoSpike.com set up a market for recordings spoken by native speakers. Anyone can post a selection of text and anyone can post a recording."
...
"Companies like RosettaStone.com, GermanPod101.com, ChinesePod.com and a surprisingly large number of other Web sites are competing to offer lessons and tutoring to students throughout the world. I found dozens of others offering what was found only on PC software a few years ago.

...
"There are even more casual approaches that come with even less infrastructure and fewer of the protections for consumers that it may offer. It is easy to find, for instance, people who want to practice languages with a free phone call through the forums run by Skype. One click and you can talk free with someone who wants to practice another language. The standard protocol is to spend half the time on one language and half the time with the other.

"Some sites, like UsingEnglish.com, englishcafe.com and Englishbaby.com, are devoted to helping people practice English but add the elements of sharing photos and interests like a dating service. "

Peer effects in learning and teaching, but not in golf

The October '09 issue of the American Economic Journal: Applied Economics contains three papers on peer effects.* The first of these begins "Is an employee's productivity influenced by the productivity of his or her nearby co-workers? The answer to this question is important for the optimal organization of labor...and for the optimal design of incentives." It then goes on to say that it detects no such effects from the random groupings of golfers in professional golf tournaments.

The second paper does find peer effects in random groupings of cadets at West Point, and the third paper finds that students do better when their teachers have better colleagues, i.e. they find that the teachers experience peer effects as measured by the performance of their students.

*The three papers are:

"Peer effects in the workplace: Evidence from random groupings in professional golf tournaments," by Jonathan Guryan, Kory Kroft, and Matthew J. Notowidigdo.

"The Effects of Peer Group Heterogeneity on the Production of Human Capital at West Point," by David S. Lyle.

"Teaching Students and Teaching Each Other: The Importance of Peer Learning for Teachers," by C. Kirabo Jackson and Elias Bruegmann.

Behavioral game theory on the MA Turnpike

A recent story in the Boston Globe sounds like a behavioral economics seminar on transaction costs: why are a third of the tolls on the Massachusetts Turnpike still paid (more slowly and expensively) in cash, rather than using the (now free) transponders?
Some still slow to make the move to Fast Lane: 1 in 3 tollpayers paying at booth
"The Massachusetts Turnpike Authority has made strides in signing people up to use Fast Lane, with 66 percent of tolls now paid electronically, up from 62 percent in January. But the 34 percent who use cash, and pay higher tolls at booths inside Greater Boston to do so, remain a bit of a mystery."
...
"The survey LeBovidge conducted found that the biggest hurdle to signing up more people used to be cost, accounting for about 75 percent of the abstainers. About 7 percent worried about handing personal data to the Turnpike Authority or having their movements tracked. Some remaining drivers - not reflected in the survey - come from out of state and might not have an E-Z Pass account usable in Massachusetts. Other commuters do not have a checking account or credit card.
...
"If they wait in cash lanes enough times, most technophobes get converted. Fast Lane usage at the Allston-Brighton booths rises to 86 percent during morning rush hour into Boston. Massive traffic jams also do the trick: The Easter backup helped drive signups to 45,905 in May, compared with 10,875 during the same month last year."

One reason this is an interesting problem is that it's not just about individual choice, there's an element of behavioral game theory in this kind of slow learning. Cash payers produce congestion--negative reinforcement--for other cash payers. When lines at the toll booths get really long, even the EZ Pass users have to wait on line to get to the toll booths. So slower payers provide a negative externality to everyone on the busiest days.

In a forthcoming paper in the QJE, Amy Finkelstein raises the possibility that those cash payers may also provide a small positive externality by being more politically sensitive to changes in the tolls: EZ-Tax: Tax Salience and Tax Rates.
"Abstract: This paper examines whether the salience of a tax system affects equilibrium tax rates. I analyze how tolls change after toll facilities adopt electronic toll collection (ETC); drivers are substantially less aware of tolls paid electronically. I estimate that, in steady state, tolls are 20 to 40 percent higher than they would have been without ETC. Consistent with a salience-based explanation for this toll increase, I find that under ETC, driving becomes less elastic with respect to the toll and toll setting becomes less sensitive to the electoral calendar. Alternative explanations appear unlikely to be able to explain the findings."

So the next time you are stuck on the Mass Pike behind a long line of drivers waiting to pay their tolls, try to remember that there may be a small benefit to having the toll be so salient.