Markets for Guinea Pigs

On many campuses one will find notices offering modest sums to undergraduates to participate in experiments. When the experimenter does not attract sufficiently many subjects to participate at the posted rate, does she raise it? Do undergraduates make counter offers? If not, why not?  An interesting contrast is medical research where there has arisen a class of human professional guinea pigs. They have a jobzine and the anthropologist Roberto Abadie has book on the subject. Prices paid to healthy subjects to participate in  trials vary and increase with the potential hazards. The jobzine I mention earlier provides ratings of various research organizations who carry out such studies. A number of questions come to mind immediately: how are prices determined, are subjects in a position to offer informed consent, should such contracts be forbidden and does relying on such subjects induce a selection bias?

Do No Harm & Minimum Wage

In the March 23rd edition of the NY Times Mankiw proposes a `do no harm’ test for policy makers:

…when people have voluntarily agreed upon an economic arrangement to their mutual benefit, that arrangement should be respected.

There is a qualifier for negative externalities, and he goes on to say:

As a result, when a policy is complex , hard to evaluate and disruptive of private transactions, there is good reason to be skeptical of it.

Minimum wage legislation is offered as an example of a policy that fails the do no harm test.

The association with the Hippocratic oath gives it an immediate appeal. I think the test to be more Panglossian (or should I say Leibnizian) than Hippocratic.

There is an immediate `heart strings’ argument against the test, because indentured servitude passes the `do no harm’ test. However, indentured servitude contracts are illegal in many jurisdictions ( repugnant contracts?). This argument raises only more questions, like why would we rule out such contracts? I want to focus instead on two other aspects of the `do no harm’ principle contained in the words `voluntarily’ and `benefit’. What is voluntary and benefit compared to what?

To fix ideas imagine two parties, who if they work together and expend equal effort can jointly produce a good worth $1. How should they split the surplus produced? How will they split the surplus produced? An immediate answer to the `should’ question is 50-50. A deeper answer would suggest that they each receive their marginal product (or added value) of $1, but this impossible without an injection of money from the outside. There is no immediate answer to the `will’ question as it will depend on the outside options of each of the agents and their relative patience. Suppose for example, the outside option of each party is $0, one agent is infinitely patient and the other has a high discount rate. It isn’t hard to construct a model of bargaining where the lions share of the gains from trade go to the patient agent. Thus, what `will’ happen will be very different from what `should’ happen. What `will’ happen depends on the relative patience and outside options of the agents at the time of bargaining. In my extreme example of a very impatient agent, one might ask why is it that one agent is so impatient? Is the patient agent exploiting the impatience of the other agent coercion?

When parties negotiate to their mutual benefit, it is to their benefit relative to the status quo. When the status quo presents one agent an outside option that is untenable, say starvation, is bargaining voluntary, even if the other agent is not directly threatening starvation? The difficulty with the `do no harm’ principle in policy matters is the assumption that the status quo does less harm than a change in it would. This is not clear to me at all. Let me illustrate this  with two examples to be found in any standard microeconomic text book.

Assuming a perfectly competitive market, imposing a minimum wage constraint above the equilibrium wage would reduce total welfare. What if the labor market were not perfectly competitive? In particular, suppose it was a monopsony employer constrained to offer the same wage to everyone employed. Then, imposing a minimum wage above the monopsonist’s optimal wage would increase total welfare.

Surprise and Digression

The abstract of a 2005 paper by Itti and Baldi begins with these words:

The concept of surprise is central to sensory processing, adaptation, learning, and attention. Yet, no widely-accepted mathematical theory currently exists to quantitatively characterize surprise elicited by a stimulus or event, for observers that range from single neurons to complex natural or engineered systems. We describe a formal Bayesian definition of surprise that is the only consistent formulation under minimal axiomatic assumptions.

They propose that surprise be measured by the Kullback-Liebler divergence between the prior and the posterior. As with many good ideas, Itti and Baldi are not the first to propose this. C. L. Martin and G. Meeden did so in 1984 in an unpublished paper entitled: `The distance between the prior and the posterior distributions as a measure of surprise.’ Itti and Baldi go further and provide experimental support that this notion of surprise comports with human notions of surprise. Recently, Ely, Frankel and Kamenica in Economics, have also considered the issue of surprise, focusing instead on how best to release information so as to maximize interest.

Surprise now being defined, one might go on to define novelty, interestingness, beauty and humor. Indeed, Jurgen Schmidhuber has done just that (and more). A paper on the optimal design of jokes cannot be far behind. Odd as this may seem, it is a part of a venerable tradition. Kant defined humor as the sudden transformation of a strained expectation into nothing. Birkhoff himself wrote an entire treatise on Aesthetic Measure (see the review by Garabedian). But, I digress.

Returning to the subject of surprise, the Kulback-Liebler divergence is not the first measure of surprise or even the most wide spread. I think that prize goes to the venerable -value. Orthodox Bayesians, those who tremble in the sight of measure zero events, look in horror upon the -value because it does not require one to articulate a model of the alternative. Even they would own, I think, to the convenience of having to avoid listing all alternative models and carefully evaluating them. Indeed I. J. Good  writing in 1981 notes the following:

The evolutionary value of surprise is that it causes us to check our assumptions. Hence if an experiment gives rise to a surprising result given some null hypothesis it might cause us to wonder whether is true even in the absence of a vague alternative to .

Good, by the way, described himself as a cross between Bayesian and Frequentist, called a Doogian. One can tell from this label that he had an irrepressible sense of humor. Born Isadore Guldak Joseph of a Polish family in London, he changed his name to Ian Jack Good, close enough one supposes. At Bletchley park he and Turing came up with the scheme that eventually broke the German Navy’s enigma code. This led to the Good-Turing estimator. Imagine a sequence so symbols chosen from a finite alphabet. How would one estimate the probability of observing a letter from the alphabet that has not yet appeared in the sequence thus far? But, I digress.

Warren Weaver was, I think, the first to propose a measure of surpirse. Weaver is most well known as a popularizer of Science. Some may recall him as the Weaver on the slim volume by Shannon and Weaver on the Mathematical Theory of Communication. Well before that, Weaver played an important role at the Rockefeller foundation, where he used their resources to provide fellowships to many promising scholars and jump start molecular biology. The following is from page 238 of my edition Jonas’ book `The Circuit Riders’:

Given the unreliability of such sources, the conscientious philanthropoid has no choice but to become a circuit rider. To do it right, a circuit rider must be more than a scientifically literate ‘tape recorder on legs.’ In order to win the confidence of their informants, circuit riders for Weaver’s Division of Natural Sciences were called upon the offer a high level of ‘intellectual companionship – without becoming ‘too chummy’ with people whose work they had, ultimately, to judge.

But, I digress.

To define Weaver’s notion, suppose a discrete random variable that takes values in the set . Let be the probability that . The surprise index of outcome is . Good himself jumped into the fray with some generalizations of Weaver’s index. Here is one . Others involve the use of logs, leading to measures that are related to notions of entropy as well probability scoring rules. Good also proposed axioms that a good measure to satisfy, but I cannot recall if anyone followed up to derive axiomatic characterizations.

G. L. S. Shackle, who would count as one of the earliest decision theorists, also got into the act. Shackle departed from subjective probability and proposed to order degrees of beliefs by their potential degrees of surprise. Shackle also proposed, I think, that an action be judged interesting by its best possible payoff and its potential for surprise. Shackle, has already passed beyond the ken of men. One can get a sense of his style and vigor from the following response to an invitation to write a piece on Rational Expectations:

Rational expectations’ remains for me a sort of monster living in a cave. I have never ventured into the cave to see what he is like, but I am always uneasily aware that he may come out and eat me. If you will allow me to stir the cauldron of mixed metaphors with a real flourish, I shall suggest that ‘rational expectations’ is neo-classical theory clutching at the last straw. Observable circumstances offer us suggestions as to what may be the sequel of this act or that one. How can we know what invisible circumstances may take effect in time-to come, of which no hint can now be gained? I take it that ‘rational expectations’ assumes that we can work out what will happen as a consequence of this or that course of action. I should rather say that at most we can hope to set bounds to what can happen, at best and at worst, within a stated length of time from ‘the present’, and can invent an endless diversity of possibilities lying between them. I fear that for your purpose I am a broken reed.

Academic Pedigree

The other day, Andrew Postlewaite remarked that it is very hard to find a PhD economist whose academic ancestor thrice removed, was not a mathematician. Put differently, which PhD economists can trace their lineage back to Marshal, Keynes and perhaps even the Scottish master himself? An obvious problem is that it is unclear what it means for so&so to be one’s academic father. A strict definition might be thesis advisor. However, the PhD degree as we know it (some combination of study and research apprenticeship) is a relatively new thing. Arguably, the first modern PhD was granted by Yale in the early 1900s. Doctorate degrees were available in Germany prior to that. However, that degree was awarded upon submission of a body of work. There was no formal apprenticeship requirement. The UK did not introduce a doctorate degree until the early 1900s and that mimicked the German degree (and was introduced, apparently, to compete for US students who were flocking to Germany).

So, lets start at Yale with Irving Fisher. A celebrated economist, and justly so, at an institution that was the first to hand out PhD degrees. Fisher himself was a student of Josiah Willard Gibbs (mathematician and physicist, and, if you believe the mathematical genealogy project, descended from Poisson). What about Fisher’s descendants? Not a single of one of the laudatory pieces on Fisher here mention his students. Some digging uncovered James Harvey Rogers, who went on to become Sterling Professor of Economics at Yale and a panjandrum in the treasury. The university maintains an archive of his papers . Rogers also studied with Pareto. Rogers begat Walt Whitman Rostow. Rostow begat Everett Clyde Upshaw and that is where the line ends.

Lets try one more, Richard T. Ely, after whom the AEA has named one of its lecture series and credited as a founder of land economics. The Kirkus review of 1938 warmly endorses his biography, `The Ground Under our Feet.’ Ely begat John R. Commons, W. A. Scott and E. A. Ross. Commons begat Edwin Witte,  the father of social security. Wikipedia credits Commons with influencing Gunnar Myrdal, Oliver Williamson and Herbert Simon, but `influencing’ is not the same as thesis advisor. But, this line seems promising, however other duties intrude.

Penn State’s Intellectual Property Auction

Penn state runs auctions to license its intellectual property. For each license on the block there is a brief description of what the relevant technology is and an opening bid which I interpret as a reserve price. It also notes whether the license is exclusive or not. Thus, the license is sold for a single upfront fee. No royalties or other form of contingent payment. As far as I can tell the design is an open ascending auction.

Development Economics

My former colleague Asher Wolinsky, once remarked that development economists had better hurry up lest the regions they studied became developed. From the March 2nd, 2014 edition of the NY Times, comes an announcement that the fateful day is upon us. The title of the piece is `The End of the Developing World‘.