Adam Smith Lives!

Experts and Influence

David Levy and I have sketched out a paper in which we check the expertise of the past.  We can do that since the data that were used by Francis Galton -- people's guesses about the weight of an ox -- have been preserved.  The paper first talks about Galton's use of the data (he chose the median guess as the best estimate of the ox weight) and then about how Galton's results were re-told, and changed over time.  Here are a couple of paragraphs from the paper, which looks at this as a case study of the role of expertise:

The question of expertise enters into this because, if experts pass along false information (wittingly or unwittingly), they become part of a process by which errors are diffused. If experts are trusted (and if they trust the experts whose work they cite), mistakes are diffused and remain uncorrected. If, by contrast, expert results are not accepted automatically, then their results are more often subject to the scrutiny associated with replication. Knowing this, an expert whose work might be scrutinized will check the work carefully. An expert who expects deference, acceptance of results without checking, will check the work less carefully. Paradoxically, such trust increases the probability of mistakes being made or passed along. Thus, we expect that the errors made by experts will tend to be systematic because they will be repeated by those who trust them.

Our examination begins with Galton’s contribution on voting as estimation as a way to bound influence. But this is only the beginning of our story. Even more interesting, perhaps, than Galton’s contribution itself, is the “retelling” that has occurred since. Though Galton was defended the median as the estimator for the ox weight, the tale of Galton’s median was changed soon after. In addition to the median location of central tendency, Pearson suggested the mean. Along the way in the historical retelling, embellishments were added so that Galton’s original procedure was entirely misconstrued. Our story recounts the misconstruing. As we do so, a key question is whether the tale was changed deliberately (falsified) or whether, not knowing the truth, the retold (and different) tale was passed on unwittingly.

A pdf of the paper will be available when we fix it.

Here's a scan of some of Galton's data:

"Vanity" at EconLog -- Analytical Egalitarianism Baffles Bryan Caplan

Bryan Caplan has a series of blogs in which he attacks Levy and Peart on analytical egalitarianism.  Caplan's main point is that people in fact differ and Levy and Peart are wrong because they fail to recognize this.  Read his argument here.  We use the opportunity to try to summarize our position on analytical egalitarianism.

As we defend it, analytical egalitarianism [AE]  is a claim about model construction. There are a class of objections to AE which presume the modeler is guided only by the desire for the truth. These are variations on the theme that

        “E isn’t true so AE can be rejected.”

We challenge this inference because we don’t believe the philosopher is guided only by the public good of truth.  Without AE, we wonder whether truth-seeking is incentive compatible.

Obviously, we are indebted to the early work in public choice which applied the homogeneity insight to those in politics: if selfish agency is assumed in markets, then selfish behavior ought to be assumed in politics.  If, conversely, selfishness is not presumed in markets, we ought not to presume it in politics.

Suppose we call this motivational homogeneity.  The step we take that others haven’t (yet) taken, is to suppose that those who model economics and politics have the same structure to their preferences as the people they model. We wish to get beyond the idea that the public choice theorist is motivated by the truth, or some statistical equivalent to the truth, from which the theorist has a vantage to look at people’s behavior.

What if the modeler has the same mix of selfish and sympathetic desires as anyone else? Then, immediately, we run into incentive compatibility issues in the space of models. AE is an attempt to block a class of issues in which the incentives seem to get in the way of truth. Consider models with agents of different fixed types.  Suppose a modeler proposes to pick who is in the “better” and who in the “worse” class.  If the modeler can do this and policies follow from the exercise, the modeler may benefit.  That’s one incentive issue.  We consider rewards from both material sources and applause.

How do we get evidence about how modelers actually work?  The history of economics and statistics seem reasonable data bases.  One case we consider at length in The 'Vanity of the Philosopher' is how Galton and Pearson obtained their “results” that Jews were inferior. The history of statistical practice in the eugenic period is full of episodes in which one “race” was treated differently than another “race.”  Impartiality might suggest that there is really only the larger group, but the partial sympathy we all feel suggests that “our group” will be viewed differently than “their group.”

Our point isn’t so much about whether “malevolent conclusions” “follow from the premises” of difference or hierarchy.  Instead, our case is that once we allow for difference to creep into the analysis, the incentives are asymmetric: the theorist gains more by showing difference than similarity.  And despite what Caplan thinks about the usefulness of knowing what such real giants in economics past or present as Adam Smith and J. S. Mill wrote about incentives and truth seeking, the past provides a rich set of data for us to examine their hypothesis of incentive incompatibility. 

One source of approval is adherence to the standards of the community as articulated in the textbooks.  So, getting closer to truth brings approbation.  In our work on statistical ethics we make the case that a temptation to deviate from these standards comes from the interaction between an expert and “his client” which offers a second source of approbation.

Ordinary people fight temptation by moral constraints.  Like Lionel Robbins, we see AE as the philosopher’s moral constraint, a constraint against the temptation from heterogeneous sources of approbation.

Though we are most interested at the moment in AE as a presumption of motivational homogeneity – of the theorist and subjects, the street porter and the philosopher – Caplan seems more interested in whether all people are really the same or different.  We have been asked several times, first by James Buchanan and more recently by David Warsh (in a review that is quite friendly to Vanity, overall), what we would say if Plato were correct, that there are fundamental differences among humans?  Setting aside the question of whether Plato’s politics are consistent with Platonism, we would look first at the history of statistical studies of human capacity to see what variation in results have been obtained. The Galton and Pearson work on the Jews is technically fascinating. Is there anyone in the Platonic camp of natural differences who defends these pieces or the general thrust of Jewish “inferiority”? If not, why not? One is unlikely to find more skilled statistical workers than Galton or Pearson. 
      
Suppose we pre-commit to some inheritable sort of capacity – which Pearson and Galton clearly did not do – and we find that one group is less capable than another. Then what? If capacity is a vector of characteristics we need to consider the various dimensions.  If there are characteristics in which groups persistently excel and characteristics on which they fall short, then it is a simple prejudice to call them less capable in some scalar sense.  If the  group is less capable in all dimensions then we are close to Hume’s other rational species problem which we talk about a good deal.  We obviously accept Smith’s answer that our capacity for sympathy equalizes; and A. R. Wallace’s answer that “natural” selection stops at the doors of such unfortunates.

Experts & Economics

Posts have been all-too-rare of late.  Work related to my fellowship with the American Council on Education, and holiday festivities, ate up the month of December.  Since most stories relating to the history of economic ideas aren't exactly time-sensitive, I figure this won't be terribly problematical for anyone out there. ;-)  After all, one of my graduate macro professors at the UofT, Angelo Melino, told me to hold off doing the history of economics until I was 65 or thereabouts.  He saw me drinking wine by a cosy fire, reflecting on the history of economic ideas in retirement.  As he put it, "they're all dead guys", so why rush to write up what they said?  Why ruin my career in economics by choosing this field that could wait some 40 years for whatever I had to say?

Was Angelo right?  Did I (and a few others I know) make a mistake by choosing to bury myself in this very small segment of the economics profession?  Angelo may have had a point (though it's not the one he meant to make) -- it may be that as one has more time to read and reflect, one writes better pieces in the history of economic ideas.  I've come more fully to understand the significance of (say) J. S. Mill or T. R. Malthus only after reading and rereading them, along with a great deal of contextual material.  Whether that's as true of other fields in economics or not, is another question.

But secondly, I've come to see that the history of economic ideas is in fact much more woven into our day-to-day lives than I might have imagined, earlier on.  Tonight, I have in mind the idea of "experts" -- economic or otherwise -- and ordinary people.  Specifically, recent reports of major scientific fraud related to cloning research:

When Dr. Hwang Woo Suk's recent reports of advances in cloning research were declared to have been fabricated on Friday, his disgrace left scientists wondering how he had risen so fast, deceived so many and fallen so hard.

The NYTimes account is here. 

What does the Hwang or any other story about scientific fraud have to do with the history of economic ideas or economics more generally?  Economists in our past have had important things to say about the incentives faced by experts.  But since we no longer know economists who wrote in the past, most of us are at a loss to find texts or analyses in economics that address this issue.  Yet economists, who write about incentives and economic man (including scientists), should be at the forefront of examining the incentives faced by scientists and the outcomes we might expect from those incentives.  And there's a great deal of historical material that bears on the issue, related but not limited to eugenics and eugenic "evidence" that passed muster among social scientists.  One of the major thrusts of the Vanity of the Philosopher, is that the past provides a cautionary tale for all of us who consider ourselves to be "experts" of some sort.