クルーグマン4/15ブログエントリで自分のAssociation of American Geographersの4/16講演草稿にリンクしている。その草稿は「The New Economic Geography, now middle-aged」と題されている。



Actually, the reaction was even worse than I expected. As it happens, starting in the 1980s many geographers were moving even further from mainstream economics -- there was a widespread rejection not just of the assumptions of rational behavior and equilibrium, but of the whole notion of mathematical modeling and even the use of quantitative methods
As a result, there have been some detailed, impassioned critiques of the economists’ version of economic geography from the geographers. Notably, Martin (1999) has argued that “economic geography proper” involves “a firm commitment to studying real places (the recognition that local specificity matters) and the role of historico-institutional factors in the development of those places.” And it involves a rejection of abstract models in favor of “discursive persuasion.”


1. Full microfoundations: This was going to be a neoclassical model in the broad sense – not a model of perfect competition and efficient markets, but one in which economic outcomes can be represented as the equilibrium that results when maximizing individuals interact. You don’t have to believe that this is a literal description of the economy – I certainly don’t – to recognize that it’s an approach that has shown a lot of power to make sense of the world, and my goal was to exploit that power, not challenge it.
2. No dormitive properties: The reference is to Moliere’s doctor, who triumphantly explains that opium puts people to sleep because of its dormitive properties. The economics equivalent is the assertion that production clumps together because of agglomeration economies; I wanted to derive those agglomeration economies from something more fundamental, such as the interaction among economies of scale, transportation costs, and market size. This meant, among other things, downplaying invisible external economies like information spillovers.
3. Distance between assumptions and conclusions: This is a little hard to explain if you aren’t in the modeling business, but there’s a broad sense, which I share, that you’re learning more from a model if the rabbit isn’t stuffed too visibly into the hat just before the theorist pulls it out. That’s why I didn’t follow Fujita (1988) in assuming that there are nontraded inputs produced with economies of scale; even if that’s reasonable in many cases, it would be more interesting to show agglomeration emerging without such a strong assumption.
4. More than one possible outcome: It seemed, from both an aesthetic and a historical point of view, that a model in which agglomeration didn’t have to happen, in which results depend on parameters, would be more interesting than one in which emergence of an industrial core were preordained.
Oh, and one more thing: the model had to be tractable, something you could analyze with pencil and paper and understand what was going on.


  1. 完全なミクロの基礎付け:
  2. 催眠作用を持たないこと:
  3. 仮定と結論の間に距離があること:
  4. 導出可能な結果が複数あること:



Now there are, obviously, factors that will loom much larger at the level of individual industrial clusters than at the level of broad core-periphery patterns. I found myself invoking the Marshallian trinity: specialized providers of industry inputs, thick markets for specialized labor skills, and information spillovers (I think, though I’m not sure, that I can claim credit for the new popularity of Marshall’s wonderful line: “The mysteries of the trade become no mystery, but are, as it were, in the air.”) I think it’s fair to say, however, that my own work – and to some extent that of others – tended to favor the first two elements of the Marshallian trinity over the third. Why? It goes back to the no-dormitive-properties pledge: once you start invoking information spillovers to explain agglomeration, it’s a bit too close to just assuming agglomeration.
But here’s the thing: the no-dormitive-properties imperative led the new economic geography to emphasize tangible causes of economic concentration in a world that seems increasingly dominated by intangibles. How can you deemphasize technology and information spillovers in a world in which everyone’s prime examples of localization are Silicon Valley and Wall Street? Ever since the beginnings of new economic geography, and up until very recently, I and others have had a slightly guilty sense that we were talking about the past, not the present, and much less the future.
中心−周縁の一般的なパターンというレベルよりも、個々の産業集積といったレベルにおいてその存在感を大きく増す要素があることは疑いない。それについてはマーシャルの三要素を思い出す。産業の投入財に特化した供給者、特殊な労働技能の市場の厚み、そして情報の波及(マーシャルの素晴らしい言葉「取引の神秘は神秘でなくなり、いわば空気中に存在するようになる」が新たに人気を集めたのは、確信はないが、多分私のせいだと思う)、の3つだ。しかし、私自身の仕事、そして私以外の人の仕事もある程度までは、このマーシャルの三要素のうち最初の2つを3番目に比べて重視する傾向があった、と言って良いと思う。なぜか? その理由は非催眠作用の誓約に求められる。情報の波及を集積の説明に用いてしまうと、集積自体を仮定しているのとさほど変わらなくなってしまうのだ。
しかし、これが困った点でもある。非催眠作用の制約は、無形資産がますます支配力を高めているように見える世界において、新経済地理学が、経済集積における有形資産の要因を強調する結果をもたらした。誰もが持ち出す地域特化の代表例がシリコンバレーウォール街であるような世界において、技術と情報の波及効果を貶めるようなことがどうしてできようか? 新経済地理学の提唱当初から、つい最近に至るまで、私や仲間達は、現在ではなく過去について話しており、未来は蚊帳の外に置いている、という微かな罪悪感を持っていた。


And guess what? Chinese economic geography is highly reminiscent of the economic geography of advanced nations circa 1900 – and it fits gratifyingly well into the new economic geography framework.
In sum, it turns out that the concepts and approaches of the new economic geography aren’t backward-looking after all. They’re utterly relevant to understanding developments in the world’s fastest-growing economies. Localization in America has become a subtle affair, but in China and other emerging economies, it’s anything but subtle, and there’s wide scope for the use of no-dormitive-properties models to make sense of what we see.
そして何が起きたと思う? 中国の経済地理は、先進国の1900年頃の経済地理に良く似ているんだ。そして面白いほど新経済地理学の枠組みが良く当てはまる。

*1:Martin, Ron (1999), “The new „geographical turn‟ in economics: some critical reflections”, Cambridge Journal of Economics.


*3:cf. これ、もしくはこれのpp.49-50。

*4:FUJITA,M. (1988).A monopolistic competition model of spatial agglomeration: a differentiated product approach, Region. Sci. Urban Econ. 18, 87–124.