Incommensurability, welfare economics, and the law.

• Author: Craswell, Richard
• Position: Symposium: Law and Incommensurability

In the philosophical literature on values and practical reason, a debate has arisen over the thesis that certain goods or values are incommensurable.(1) This raises an obvious question for legal scholars: Would this thesis, if true, have implications for the law? Several authors have claimed that it would, by challenging various economic justifications for legal decisions.(2)

One purpose of this Article is to argue against that claim. To make this argument, though, a good deal of clarifying work is required. Economic arguments can be criticized on many different grounds, but each criticism rests on a slightly different footing, and many have little to do with incommensurability. Thus, a second purpose of this Article--and perhaps the more important one--is to try to clarify the various arguments.

The need for clarification stems partly from the differing aims of philosophers and economists. Some of the philosophical writings on incommensurability aim to develop a descriptive account of individual choice, arguing (in particular) that choices are not adequately described as if the individual picked whichever option ranked highest in some single value. Much of this literature also aims to develop a theory of practical reason or rational action--that is, a theory of how individual choices ought to be made--arguing that individuals should not pick whichever option ranks highest in some single value. But both of these aims concern individual choice: neither directly addresses questions about how government decisions ought to be made. And on the other side of the divide, welfare economists--who do purport to be addressing government decisions--have not always been very clear what they assume regarding individual choice. As a result, in many discussions of incommensurability and law, the participants end up talking past one another, and the issues are never truly joined.

My interest in this Article concerns the proper bases for government decisions, or for the law. Thus, for most of the Article I assume that the theories of incommensurability are correct,, as far as individual decisions are concerned, in order to trace out the possible implications for government. Part I of the Article explains more precisely what I mean by incommensurability, and Part II clarifies what I take to be the presuppositions of welfare economics. The bulk of my argument, however, appears in two main substantive sections.

Part III begins by asking what would follow from the incommensurability of values in an admittedly unrealistic scenario, in which only a single individual would be affected by some government decision. Few legal decisions fit this extreme assumption, but in untangling the possible consequences of incommensurability, I find it a useful heuristic to consider which consequences might apply even in so extreme a case. Part IV then turns to the more realistic case of a decision that affects different individuals in different ways. In such a case, mainstream welfare economics already recognizes one form of incommensurability involving interpersonal comparisons of utility, but this has not been the focus of the philosophical writings on the incommensurability of goods or values. Thus, most of Part IV considers methods of interpersonal comparison that are sometimes used by economists, such as the Kaldor-Hicks criterion, and the possible alternatives that might be required by various theories of incommensurability. I conclude that most of these alternatives are either unsound or have not yet been developed to the point where we can judge their soundness.

1. SOME DEFINITIONS

   1. Incommensurability

      As many have noted, there is no standard definition of "incommensurability."(3) For purposes of this Article, I take the claim that two options are incommensurable as a claim about the possible justifications for choosing one option over the other. More precisely, I take incommensurability to mean that there is no scale or metric that (1) would satisfy the property of completeness, meaning that one of the options must rank higher on the scale or they must both rank exactly equal; and (2) would justify the choice of whichever option ranked higher.

      I focus on justifications for decisions because this is when incommensurability becomes important for the law (as well as for welfare economics). It is one thing to ask, in the abstract, whether a beautiful mountain gorge can meaningfully be valued on the same scale that we use to value cheaper electricity. But this question has the most bite when the law for some reason must choose between these values--for example, if there is a proposal to build a dam that would flood the gorge. Welfare economics purports to offer a basis for evaluating that decision and for justifying one choice rather than the other. My interest in incommensurability, therefore, is in the extent to which it undermines this justification.(4)

      My focus on justifications will force me to consider ethical or political questions about what counts as a legitimate justification for government action. But any discussion of incommensurability must implicitly raise such questions, for any two goods can always be ranked on some scale. That is, the mountain gorge and cheaper electricity can clearly be ranked on arbitrary scales such as alphabetical order or, to use Ruth Chang's example, "pleasingness to my grandmother."(5) In my terms, though, a claim that two options are incommensurable must be a claim that they are incommensurable for some particular purpose: it is a claim that some particular decision cannot be justified by ranking the options along any single metric.(6) Thus, the reason arbitrary scales cannot supply commensurability is because they are irrelevant to any decision about building the dam. Whether the criteria of welfare economics are similarly irrelevant will be taken up below.

      Notice, too, that the problem with arbitrary scales is not simply that they provide an inaccurate description of the goods involved, or that their description is inadequate or incomplete.(7) After all, every description will be incomplete in some respect, so the completeness or adequacy of a description can only really be judged by reference to the purpose for which the description will be used. In this Article, I am interested in the purpose of justifying government decisions, so I view descriptive inadequacy as a problem when (but only to the extent that) it undermines some justification for a government decision. To see whether any particular inadequacy is a problem, the justification that is purportedly undermined by it will have to be spelled out explicitly.

   2. Commodification

      My definition of incommensurability is meant to distinguish it from the related issue of commodification. I take commodification to be a concern over one possible effect of describing or justifying choices as if they were commensurable--and, also, one possible effect of adopting certain legal rules, such as allowing babies to be sold for money. Specifically, the concern is that justifying choices in this way (or permitting people to take certain actions) could alter the way that people view the goods themselves, and this effect could be undesirable. For example, if babies regularly are bought and sold, this could lead people to think of babies as nothing more than financial assets. Or if hydroelectric dams are justified using the criteria of welfare economics, this could cause people to lose their reverence for nature.(8)

      In this Article, I do not address criticisms of welfare economics that are based on commodification. These criticisms raise empirical questions about cognitive and social psychology, and while these are clearly topics of importance, they are also topics on which I have little to say.(9) Moreover, the answer to these empirical questions need not depend in any way on the normative question that is my focus here--that is, whether welfare economics provides a metric or scale that is an acceptable justification for public decisions. After all, even if welfare economics supplies a normatively acceptable justification, its use might still produce undesirable psychological consequences (which could then provide a different reason for objecting to its use). Conversely, even if welfare economics does not supply a normatively acceptable justification, this does not establish that its use also would produce undesirable psychological consequences. In short, there are some issues of justification that are logically independent from the question of psychological consequences, and these independent justificatory issues will be my focus here.

2. THE PRESUPPOSITIONS OF WELFARE ECONOMICS

   As noted earlier, most of the philosophical literature on incommensurability has focused on individual choice. For example, if the individual must choose between a career as a lawyer and a career as a philosopher, a claim that these two options are incommensurable is a claim that there is no single scale that would both: (1) rank the career as a lawyer either higher or lower than the career as a philosopher; and (2) count as an acceptable normative reason for choosing the higher-ranking career.

   It is important to note that, according to most accounts of incommensurability, the lack of such a scale would not prevent the individual herself from choosing between the two options.(10) That is, few if any writers argue that an individual faced with a choice between incommensurable options is therefore paralyzed, unable to make any decision at all (like Buridan's ass). Instead, the incommensurabilist's claim is a claim about the possible justifications for whatever choice the individual eventually makes. Specifically, it is the negative claim that the justification for that choice cannot be found in any scale that ranks one career higher than the other.

   1. Individual Utility Functions

      We must now consider what implications this claim would have for welfare economics. My thesis...