ジェームズ・ブキャナンが表題の小論を書いているMarginal Revolution経由;原題は「Economists Have No Clothes」)。以下に掻い摘んで紹介してみる。

1. イントロダクション(Introduction)

Economists are embarrassed by their inability to offer ‘scientific’ explanations for the 2008–9 crises or to advance suggestions for reform. And for the few who have dared enter the political dialogue, the arguments seem to differ little, if at all, from the nostrums offered three-quarters of a century past by Keynes and his converted disciples. It seems as if, for economists, the whole post-Keynesian epoch must be judged to be a sequence of lost generations from whom no value product emerged at all.


2. 制御なき計測(Measure without Control)

The Keynesian-inspired separation of macroeconomics from microeconomics that took place in midcentury seemed to embody genuine scientific advance. The attention of many economists was shifted to measure the aggregate variables that seemed adequate to describe the macroecomy.
Unfortunately, economists, generally, failed to understand that aggregate variables that may be measured with tolerable accuracy ex post may not be variables subject to control, directly or even indirectly. The fundamental misconception here lies in the understanding of what ‘the economy’ is. The ‘economic problem’ is not (despite Lionel Robbins) an engineering problem that may be defined simply as the allocation of scarce resources among alternative uses. The economy, in some inclusive definitional sense, is perhaps best described as an order that consists of an interlinked set of exchanges, simple and complex, from which outcomes emerge that may in some respects be meaningfully measured but that cannot be chosen, and thereby controlled, by concentrated decision takers.
Economists do not really understand what they are doing as they seem forced to make efforts to control aggregate variables that are not controllable in any direct sense. For example, the rate of employment (or unemployment) cannot readily be shifted by governmental mandate. At best, small and peripheral
changes may be made while the emergent aggregate generated by the working of the large and complex economy remains stubbornly immune, or worse, to wrongly conceived reform efforts.


3. 欠けている探究の道筋(The Missing Avenue of Inquiry)

My own position has long been clear. I entitled my 1986 Nobel lecture, The Constitution of Economic Policy. Economists should have paid, and should now pay, attention to the constitutional structure within which actors play out the multitude of transactions that describe the market order, whether these actions be taken in roles as consumers–buyers, sellers–investors, employers–employees, individuals–firms.
How do markets work? Standing alone, this is an inappropriate and unanswerable question. It must be replaced by the question: How do markets work under this or that set of constitutional and institutional constraints? Economists’scientific expertise can be brought to bear on the predicted effects of alternative sets of constraints. The relevant question is not that of asking how this or that
end-state or outcome may be put in place through possible collective or political action. The question becomes, instead, how can this or that set of constraints be predicted to operate so as to allow the generation of an order that meets certain criteria of desirability? The difference between the two methodological stances may appear minor, but much ill-advised effort might be avoided if economists would recognize the limits of their own discipline.

市場はどのように機能するのか? この問い自体は、不適切で回答の存在しない質問である。それは次のように言い換えられねばならない:あれやこれの基本ルールや制度の制約の集合において、市場はどのように機能するのか? 経済学者の科学知識は、別の制約集合のもたらす影響の予測に使えるだろう。それと関連する質問は、可能な集合的ないし政治的行動によって、どのようにあれやこれやの最終状態ないし結果が得られるか、ではない。問うべき質問は、どのようにあれやこれやの制約集合の挙動を予測し、それによって一定の望ましい基準を満たす秩序を生み出すか、である。この二つの手法の立場は大差無いように見えるかもしれない。だが、経済学者が自分の学問の限界を認める意思があるならば、悪しき助言による苦労は大幅に減らせるだろう。

4. 理想の世界(Ideal Worlds)

In a recent lecture, I labeled myself as a ‘natural pragmatist’ based on my continued emphasis on the recognition that any change must commence from the here and now—from the status quo that describes current reality. But there is a feedback relationship of a sort between this position and the one encountered in the statement ‘but you can’t get there from here’. Realization of the dilemma here has made me change my stance to a degree. It now seems more evident that any change from the here and now, to be at all meaningful and potentially productive, must be informed by some ultimate vision of how things might be, no matter how vague and cloudy such vision must be. We must engage our thinking
and analyses of worlds that might be, ideal worlds if you will, while keeping within the boundaries of the possible.
The procedure is, then, one of moving beyond the obvious limits of what might be by the construction of idealizations that remain possibly attainable, but which have not been fully examined and analyzed. Why have political economists, in particular, been apparently so willing to accept as sacrosanct the monetary framework in being? Why has not more attention been paid to alternative structures, to differing rules and institutions?
The constitutional economics of money have been almost wholly neglected for more than a half century, while professional attention shifted to idealized constructions of models remote from reality, on the one hand, to pragmatically defined within-rules alternatives, on the other. The constitutional economics of money must, in some ultimate sense, have teleological purpose. The aim is to evaluate differing sets of rules and to place these in some order of preferability.
But, as noted, the end-states that may emerge under any set of rules are drawn, as it were, from a distribution as determined by the whole complex of interlinked exchanges generated by the choices made by separate choosers. It is folly to interpret the whole exercise as the search for unique or even narrowly defined results. Such conceptualization would be analogous to choosing the rules for an ordinary game with, once chosen, the rules themselves predicted to guarantee specific outcomes, while the choices of the players in the game itself being without effect.

そう考えると、なすべきことは、達成可能な理想の実現に対し明らかに制約を課すと思われるが、しかしながら十分に調査分析がなされていない限界を超えて考えることだ。なぜ政治経済学者は、たとえば既存の金融の枠組みを、神聖不可侵のものとして受け入れてきたのか? なぜ別の枠組み、今とは異なる規則や制度に目を向けなかったのか?

5. 基本ルールの革命?(Constitutional Revolution?)

In the parlance of theoretical welfare economics, there occurred a Pareto-inferior shift in which all persons in the nexus were made worse off by their own utility calculus. The utility functions seemed to have all shifted inward. What happened? It is as if all participants in the inclusive economic nexus were riding along on a donkey seated quite comfortably on a saddle of inflated air, until an unanticipated rupture collapsed the cushion.
What seems noteworthy here is that the deflation of the ‘hot air’ in the banking-financial sector did not benefit any defined subset. The loss in utility seemed to be general over the whole and inclusive market economy. The events were such that they could have scarcely been generated by any identifiable group whose aim was to exploit others.
Critical evaluation and assessment suggests that the structure of the whole monetary economy is flawed, which points toward genuine constitutional revolution rather than either a change in participants or piecemeal adjustments in the regulatory apparatus.

(2008年の危機において)厚生経済理論の用語で言えば、パレート改悪的な変化が起き、関係者すべての自分から見た効用が悪化した。効用関数がすべて内向きにシフトしたのだ。何が起きたのか? それはあたかも、経済活動に関係する者が皆、ロバの背に置かれた空気で膨んだ鞍に心地よく乗っていたところ、予期せぬ破裂でそのクッションが萎んでしまったようなものだ。

6. 貨幣中立性に向けて(Toward Monetary Neutrality)

It is necessary to understand and appreciate, however, that, even if this market had never existed, some other elements would have proved to be vulnerable to unanticipated collapse. The familiar ‘house of cards’metaphor surely is applicable.
Radical rethinking is required here—a rethinking that has not occurred since the Great Depression.
Individual choices to shift nominally valued assets among differentially leveraged accounts cannot be allowed to generate multiplier effects over the whole system. Some modern equivalent of one hundred percent, or full, reserve banking must finally be installed and enforced. The Glass-Stegall efforts to separate deposit and investment banking should presumably be updated and put in play. Some extension-application of the antitrust laws to the banking conglomerations seems to be in order here.


7. 貨幣の基本ルール化(The Constitutionalization of Money)

The value of the monetary unit, the United States dollar in the setting of early twenty-first century, can, and must, be treated as a ‘relatively absolute absolute’. Along with the other required institutional changes, some of which are noted above, this value can be operative as an anchor for exchange transactions at all levels.


8. 経済学者の課題(The Challenge for Economists)

Economists, and perhaps those are most closely associated in their inquiries with the monetary institutions in being, have almost totally failed in their basic understanding of the constitutional elements that must be present in any viable regime. In particular, these economists are unlikely sources of inspiration for the quantum leaps in attitudes that are needed here. There is no need for some ‘beyond science’ competence. As in other aspects of modernity, return to classical understandings and their implications could be transformative. It is time that nonmonetary economists return to their elementary textbooks.
It is also praiseworthy that both nonprofessionals and professionals from other disciplines join economists in the unique opportunities now presented.



STUPIDEST THING I HAVE READ TODAY: James Buchanan: Economists Have No Clothes:

What function must the whole financial-monetary structure perform in an ideally working market economy? This question is relatively easy to answer. The financial-monetary structure must be neutral in its allocative effects. It must be limited to the facilitation of exchanges (to the reduction of transactions costs)...

If other economists have no clothes, then I suspect James Buchanan must have neither clothes, skin, organs, or bones. The financial-monetary sector does a lot more than facilitate exchange--a problem that was solved by the invention of coinage under Gyges King of Lydia 2800 years ago. The financial-monetary structure does facilitate exchange, but that is only one of its roles. Its major role is to transform the forms of wealth that exist in the economy into forms of wealth that savers want to hold. The forms of wealth that exist in the economy are long-term illiquid risky projects and organizations that require a good deal of supervision and oversight. The forms of wealth that savers want to hold are short-term liquid safe assets that can be left to manage themselves. To move from one to the other financiers must (a) find people tolerant of bearing risk, (b) people willing to monitor and oversee, (c) people to make markets to create liquidity, while (d) betting that the law of large numbers can keep the whole thing from crashing down as they try to maximize their profits by paying the minimum to outside risk bearers, monitors, and market-makers. "[N]eutral in its allocative effects... limited to the facilitation of exchanges," FEH!!

Five Pieces Worth Reading: February 10, 2010


理想的に機能する市場経済では、金融-貨幣構造は全体としてどのような機能を担うべきか? この問いに答えるのは比較的簡単だ。金融-貨幣構造は、分配効果において中立的であらねばならない。それは交換の促進(取引コストの削減)に限定されねばならない・・・


[追記]デロングのコメント欄でフェアリーディキンソン大学教授のロジャー・コップル(Roger Koppl)*3が以下のように反論している。

In the quoted passage the context was "an ideally working market economy." Um, Brad, that context implies that, er, all goods are, you know, perfectly liquid.

Yes, you might indeed argue that in the rest of his short note Buchanan inappropriately neglected the liquidity considerations you raise, but that hardly makes the quoted statement stupid. Now forgive me for saying something really obvious, Brad, but his neglect of your issue simply reflects his rather different diagnosis of the problem. That hardly makes him a dolt!



*1:Marginal Revolutionのタイラー・コーエンは、この最後の段落を紹介エントリで引用している。

Frank Knight directly taught me the philosophical principle that has served me so well over so many years and in so many applications. This principle is that of the relatively absolute absolute, which allows for a philosophical way station between the extremes of absolutism on the one hand and relativism on the other, both of which are to be rejected.