Feliz Nochebuena; Happy Christmas Eve! As readers of this blog may know, I have long been fascinated with Ronald Coase’s counter-intuitive insight that harms are a “reciprocal” problem. What you may not know, however, is that this simple idea has haunted me since the fall of 1990, my first semester of law school, when I was Guido Calabresi’s torts student at Yale, for it was in one of Guido’s legendary torts lectures that I was first exposed to Coase’s paper The Problem of Social Cost, the landmark work in which Coase introduces his reciprocal-harm model.

Since then, I have published no less than 10 scholarly papers (see here, for example) in which explore various aspects of Coase’s work, but the one idea that continues to haunt me the most is Coase’s reciprocal-harm thesis. Why has the idea of “reciprocal harms” haunted me for so long? Because if Coase is right, if harms are a reciprocal problem, this proposition would have radical and far-reaching implications for moral and political philosophy. But is Coase right? Are harms really reciprocal? Also, how would we prove (or disprove!) this claim? Is Coase’s model of reciprocal harms falsifiable in the Popperian sense?

Here is where my most recent work-in-progress on reciprocal harms (“Coase’s fable”, available here) comes into play, for I have now decided to describe Coase’s destabilizing insight that harms are a reciprocal problem as an axiom. My reason for making this move is strategic: to sidestep the truth and proof questions I posed above, for axioms are supposed to be self-evident. [On this note, see footnote 6 of my paper, where I define an axiom as “a statement of proposition that is regarded as being self-evidently true”.] I concede, however, that calling Coase’s insight an axiom now opens up a new can of pesky philosophical worms, so to speak. Among these are: why are axioms “self-evident”, and is Coase’s reciprocal-harm model really an axiom?

Regarding these deeper questions, I have found Robert G. Brown’s book-length work on the history and nature of axioms to be helpful. To the point, according to Brown, a physics professor at Duke, an axiom is just a starting point, an assertion or proposition that we simply assume to be true for the sake of argument: “an axiom is not necessarily a self-evident truth, but rather a formal logical expression used in a deduction to yield further results.” [1] In other words, axioms are exempt from the necessity of independent proof: you either accept Coase’s insight as true, as an accurate or useful model of reality, or you don’t.

But even if we are prepared to accept Coase’s reciprocal-harm model as an axiom (in order to sidestep truth and proof questions about the model), we still have an even more important question to address: what is the scope or domain of Coase’s axiom? Does the reciprocal-harm model apply only to economic harms, to involuntary harms more generally, or to all harms? I will address this deeper question in my next post …

[1] Robert G. Brown, Axioms (2007), https://webhome.phy.duke.edu/~rgb/Philosophy/Axioms/axioms/ [https://archive.ph/SrpLc]. See also Yuri Balashov and Alex Rosenberg (editors), Philosophy of Science, London and New York: Routledge (2002), pp. 129-131.