9. 2015年9月01日 21:07:08
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経済学の過去・現在・将来とは＝IMFチーフエコノミスト国際通貨基金（IMF）のチーフエコノミスト、オリビエ・ブランシャール氏 PHOTO: AGENCE FRANCE-PRESSE/GETTY IMAGES
IAN TALLEY
2015 年 9 月 1 日 12:59 JST 世界経済危機が始まった2008年に国際通貨基金（IMF）のチーフエコノミストに就任したオリビエ・ブランシャール氏は、世界金融市場の混乱のさなか今月末で退任する。 だがブランシャール氏の就任当時と現在とでは、世界の経済情勢は大きく様変わりした。 IMFが発行する研究誌の最新号で、ブランシャール氏は世界経済の近年、現在、将来、そして科学としての経済学（あるいは魔術との見方もあろう）について概説している。 以下に注目すべき箇所を抜粋する。 近年： 「金融危機をきっかけに、マクロ経済学の存在そのものが危機にさらされることとなった。マクロ経済は実務上、かなり安定した集合体の関係が存在していることを前提としている。つまり、個人や企業、金融機関の経済活動を個別に把握する必要はなく、ミクロ経済レベルの詳細な動きまで理解しなくてもよいということだ。われわれは（金融危機で）金融部門を筆頭にそうした精査が重要であることを知った。同じ集合体の中にマクロ経済の重大な問題が隠れていることもあるのだ。ではマクロ経済にどう向き合えばよいのだろうか」 「ギリシャ支援交渉を進める中で、債務減免すべきだという議論はまず非公式に行うのが道理にかなっていた。実際、最初は非公式な場で検討された。そして交渉が進展しないと思った時点で議論を公にしたわけだが、これは筋が通っていた。最初から公にしていれば、それは間違いだった。ずっと非公開のままにしていたとしても、まずかっただろう」 「私が長らく思案してきた問題は、見解が変わったときに、「過ち」、「無能なIMF」などとメディアに大きく報じられることなくこのことを表明するにはどうすればよいかということだ。財政乗数を考えてみたい。財政再建による国内総生産（GDP）押し下げ効果を過小評価していたことは、エクセルのスプレッドシートで二つのセルを取り違えるといった、普通に言う「間違い」ではなかった。これは大量の事前証拠に基づいての評価だった。ただ、金利がゼロ近辺にあり、金融政策が財政緊縮による悪影響を相殺できない状況では、そうした証拠は紛らわしいものだったのだ。過小評価を認めたことで、われわれは激しい非難を浴びた。今後も批判を受け続けることと思う。だが同時に、IMFは信頼性を大きく向上させ、その後、使う前提も改善した。つらいプロセスだったが、有益だった」 現在： 「生産性の伸びが低い時代に入った公算が極めて大きい。構造的に需要が低迷し、超低金利が必要な時代に入った可能性がある。低成長と不均衡拡大とが併存する状況は道徳的に受け入れ難いだけでなく、政治的にもあまりに危険だ」 「マクロプルデンシャル（金融市場の安定性を維持する）政策手段であれ資本統制であれ、（経済政策立案の傾向として）市場重視から政府介入へと振り子が振れているのは明らかだ。大半のマクロ経済学者からすれば、これは最善とは言えない世界だ。ただ、こうしたシフトは意外な展開を見せている。政府介入の効果について懐疑的な見方が広がっているのだ」 「昔ならあり得ないと思われていたはずの意見がいくつも『真面目な』エコノミストから提案されている。財政ファイナンスによる赤字穴埋めなどだ」 将来： IMFの今後の主要な役割の一つは「流動性供給だろう。資産・負債総額がネックとなり、大量の資金供給が突然止まる恐れがある。その場合、国際機関による非常に大規模な流動性供給が必要になる。中央銀行のスワップ協定とIMFの流動性プログラムが偶然にも共存している現行体制は奇妙な構造だ。どの国にどの機関から流動性を供給するかという判断に政治的要素が関与しないようにするためにも、この体制を改善する必要がある。（中銀とIMFの）二つの機能をもっとうまく統合し、当該国・地域の合意とも一体化すべきだ」
http://blogs.wsj.com/economics/2015/08/31/the-past-present-and-future-of-economics-according-to-olivier-blanchard/ http://www.imf.org/external/pubs/ft/survey/so/2015/res083115a.htm
Blanchard: Looking Forward, Looking Back
IMF Survey August 31, 2015 IMF Chief Economist Blanchard to step down end September
Financial crisis raises potential existential crisis for macroeconomics
Need to address longer term issues of low productivity growth, increasing inequality
Olivier Blanchard will step down as Economic Counsellor and Director of the IMF's Research Department at the end of September.
He will join the Peterson Institute for International Economics in October as the first C. Fred Bergsten senior fellow, a post named for the founder of the influential 35-year-old, Washington-based think tank.
When French-born Blanchard, a former chairman of the economics department at the Massachusetts Institute of Technology, joined the IMF on September 1, 2008, little did he realize that he would be at the center of a global economic storm. Two weeks later, Lehman Brother’s bank collapsed, marking what many consider the start of the 2008-09 global financial crisis.
“The crisis was a traumatic event during which we all had to question many cherished beliefs,” said Blanchard. This included questioning various assumptions on the role of fiscal policy, including the size of fiscal multipliers, the use of unconventional monetary policy measures and macroprudential tools, capital flows and measures to control them, labor market policies and the role of micro and macro flexibility. “And being in a position to question gave me the opportunity to make a difference,” he said. C:\Users\GBhatt\AppData\Local\Microsoft\Windows\Temporary Internet Files\Content.Outlook\ZCNPDUIX\001031025.jpg Blanchard says he now wants to take the time to research fewer issues more intensely.
“For the past seven years, he says “I’ve been answering a thousand questions, but not in a very deep way. I want to take ten of these thousand questions and answer them more deeply.” One of the issues he plans to examine is the various measures countries can use to control and mold capital flows.
IMF Survey interviewed Blanchard about global economic issues, the IMF's role in furthering economic and financial stability, and what it was like to be in the hot-seat job of chief economist.
IMF Survey: You have at times pushed the envelope of IMF thinking and policy positions. How has this been received inside and outside the IMF? Blanchard: It would have been intellectually irresponsible, and politically unwise, to pretend that the crisis did not change our views about the way the economy works. Credibility would have been lost. So, rethinking, or pushing the envelope was not a choice, but a necessity.
The fact that the economic counsellor, or the research department, has a view on a particular topic does not move things very much by itself. An essential part of the job is to convince, or try to convince, the rest of the building, from management to the department desks, of that view. This can be hard work. To treat all countries in a consistent way, the Fund must have a corpus of beliefs, and this corpus is not easily changed. Ideas do not only need to be developed, they need to be sold to the rest of the building. It does not happen overnight. With respect to outside, the issue I have been struck by is how to indicate a change of views without triggering headlines of “mistakes,’’ “Fund incompetence,’’ and so on. Here, I am thinking of fiscal multipliers. The underestimation of the drag on output from fiscal consolidation was not a ``mistake’’ in the way people think of mistakes, e.g., mixing up two cells in an excel sheet. It was based on a substantial amount of prior evidence, but evidence which turned out to be misleading in an environment where interest rates are close to zero and monetary policy cannot offset the negative effects of budget cuts. We got a lot of flak for admitting the underestimation, and I suspect we shall continue to get more flak in the future. But, at the same time, I believe that we, the Fund, substantially increased our credibility, and used better assumptions later on. It was painful, but it was useful. IMF Survey: In pushing the envelope, you also hosted three major Rethinking Macroeconomics conferences. What were the key insights and what are the key concerns on the macroeconomic front? Blanchard: Let me start with the obvious answer: That mainstream macroeconomics had taken the financial system for granted. The typical macro treatment of finance was a set of arbitrage equations, under the assumption that we did not need to look at who was doing what on Wall Street. That turned out to be badly wrong. But let me give you a few less obvious answers: The financial crisis raises a potentially existential crisis for macroeconomics. Practical macro is based on the assumption that there are fairly stable aggregate relations, so we do not need to keep track of each individual, firm, or financial institution?that we do not need to understand the details of the micro plumbing. We have learned that the plumbing, especially the financial plumbing, matters: the same aggregates can hide serious macro problems. How do we do macro then?
As a result of the crisis, a hundred intellectual flowers are blooming. Some are very old flowers: Hyman Minsky’s financial instability hypothesis. Kaldorian models of growth and inequality. Some propositions that would have been considered anathema in the past are being proposed by ``serious’’ economists: For example, monetary financing of the fiscal deficit. Some fundamental assumptions are being challenged, for example the clean separation between cycles and trends: Hysteresis is making a comeback. Some of the econometric tools, based on a vision of the world as being stationary around a trend, are being challenged.
This is all for the best. Finally, there is a clear swing of the pendulum away from markets towards government intervention, be it macro prudential tools, capital controls, etc. Most macroeconomists are now solidly in a second best world. But this shift is happening with a twist?that is, with much skepticism about the efficiency of government intervention. IMF Survey: How about longer-term economic worries? And how would these longer-term issues affect the Fund’s policy advice? Blanchard: There is a good chance that we have entered a period of low productivity growth. There is a chance that we have entered a period of structurally weak demand, which will require very low interest rates. And low growth combined with increasing inequality, is not only unacceptable morally, but extremely dangerous politically.
In assessing policies, we cannot just concentrate on short run issues, and we have to address these longer run issues. In doing so, we have to realize two things. First, that this is not our natural expertise, and we have to work with other institutions like the OECD, the World Bank. Second, that there are no magical solutions: We have to be realistic as to what structural reforms are politically feasible, and what they can reasonably achieve. IMF Survey: From your interactions with policymakers, do you get the sense that the Fund would be more effective as a trusted confidential advisor or as a key player in shaping public national and international debates? Blanchard: I think it can and should definitely be both. In the World Economic Outlook, the Global Financial Stability Report, and other surveillance documents, the Fund should be clear about the implications of major policy choices. In the bilateral assessment of a country’s economy?the so-called Article IVs?it should translate general propositions in specific policy advice. For some issues, it may make sense to take them up privately, at least first. But sometimes, making them public may be the only way to start an important discussion.
To take a familiar example, I believe that, in the context of the Greek program discussions, it made good sense to argue for debt relief first in private. We did. And when we thought our argument was not getting through, it made good sense to then go public. It would have been wrong to go public from the start, or to never go public. IMF Survey: How do you see the IMF's role evolving, particularly if there were fewer crises? Blanchard: I believe the IMF’s traditional roles of surveillance, adjustment programs, liquidity provision, and technical assistance, will still be the right ones to carry out in the future.
Surveillance. “Surveillance’’ is an awful word, but what lies behind the word is terribly important. The Fund is in a unique position to work on and describe the interactions between economies. It is in a unique position to define or at least suggest rules of the international game. Given the richness of its country experiences, and the depth of its information, it is a unique position to do essential work on open economy macroeconomics. An example: The work on capital flows we have done during the last seven years.
Adjustment programs. Their design itself needs adjustment. Given the increasing gross external asset and liability position of countries, there is a need to limit how much of the program funds go to pay short-term creditors. The reforms being now discussed at the Fund, namely the wider use of the debt rescheduling option, and the elimination of the systemic exemption, are really important.
Liquidity provision. Again, the gross asset and liability positions create the risk of very large sudden stops, and the need for international liquidity provision on a very large scale. The current haphazard combination of central bank swap lines and Fund liquidity programs is a strange contraption. It should be improved, if only to eliminate the role of political factors in who gets what. The two should be better integrated, and integrated with regional agreements.
Technical assistance. Through my seven years at the Fund, I have been struck at how invaluable our technical assistance and capacity building can be. Given its knowledge and its close relation with its members, the Fund is in a unique position to provide advice, from how to design an inflation targeting regime to how to improve tax collection. Doing even more would be good. IMF Survey: How do you think an economic counselor should balance the duties of spokesperson of the IMF and the role of an academic/ researcher generating new ideas, especially when such ideas conflict with IMF orthodoxy? Blanchard: I have not found this to be an issue. Not once in my seven years have I felt I had to avoid or fuzzy up a position I held, or had to present a position I did not believe in. If I had, I suspect I would have offered to resign.
People who expect me to bare my soul after I leave the Fund will be disappointed. What you got is what you’ll get. IMF Survey: You will not be going too far. What will you focus on at Peterson Institute? Blanchard: I want to go back to doing research on a few specific issues. For the past seven years, I’ve been answering a thousand questions, but not in a very deep way. I want to take ten of these thousand questions and answer them more deeply.
I want to go back and examine what happened in Portugal, in Ireland, in Iceland, in Greece, and do the in-depth work that none of us has the time to do. I want to think harder about the various measures countries can use to control and mold capital flows. In short, I want to continue to “rethink macro’’… http://www.project-syndicate.org/commentary/robert-j--shilleron-whether-he-is-a-scientist
Robert J. Shiller
Robert J. Shiller, a 2013 Nobel laureate in economics, is Professor of Economics at Yale University and the co-creator of the Case-Shiller Index of US house prices. He is the author of Irrational Exuberance, the third edition of which was published in January 2015, and, most recently, Finance and th… read more
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Is Economics a Science?
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NEW HAVEN ? I am one of the winners of this year’s Nobel Memorial Prize in Economic Sciences, which makes me acutely aware of criticism of the prize by those who claim that economics ? unlike chemistry, physics, or medicine, for which Nobel Prizes are also awarded ? is not a science. Are they right?
One problem with economics is that it is necessarily focused on policy, rather than discovery of fundamentals. Nobody really cares much about economic data except as a guide to policy: economic phenomena do not have the same intrinsic fascination for us as the internal resonances of the atom or the functioning of the vesicles and other organelles of a living cell. We judge economics by what it can produce. As such, economics is rather more like engineering than physics, more practical than spiritual.
There is no Nobel Prize for engineering, though there should be. True, the chemistry prize this year looks a bit like an engineering prize, because it was given to three researchers ? Martin Karplus, Michael Levitt, and Arieh Warshel ? “for the development of multiscale models of complex chemical systems” that underlie the computer programs that make nuclear magnetic resonance hardware work. But the Nobel Foundation is forced to look at much more such practical, applied material when it considers the economics prize.
The problem is that once we focus on economic policy, much that is not science comes into play. Politics becomes involved, and political posturing is amply rewarded by public attention. The Nobel Prize is designed to reward those who do not play tricks for attention, and who, in their sincere pursuit of the truth, might otherwise be slighted.
Why is it called a prize in “economic sciences,” rather than just “economics”? The other prizes are not awarded in the “chemical sciences” or the “physical sciences.”
Fields of endeavor that use “science” in their titles tend to be those that get masses of people emotionally involved and in which crackpots seem to have some purchase on public opinion. These fields have “science” in their names to distinguish them from their disreputable cousins.
The term political science first became popular in the late eighteenth century to distinguish it from all the partisan tracts whose purpose was to gain votes and influence rather than pursue the truth. Astronomical science was a common term in the late nineteenth century, to distinguish it from astrology and the study of ancient myths about the constellations. Hypnotic science was also used in the nineteenth century to distinguish the scientific study of hypnotism from witchcraft or religious transcendentalism.
There was a need for such terms back then, because their crackpot counterparts held much greater sway in general discourse. Scientists had to announce themselves as scientists.
In fact, even the term chemical science enjoyed some popularity in the nineteenth century ? a time when the field sought to distinguish itself from alchemy and the promotion of quack nostrums. But the need to use that term to distinguish true science from the practice of imposters was already fading by the time the Nobel Prizes were launched in 1901.
Similarly, the terms astronomical science and hypnotic science mostly died out as the twentieth century progressed, perhaps because belief in the occult waned in respectable society. Yes, horoscopes still persist in popular newspapers, but they are there only for the severely scientifically challenged, or for entertainment; the idea that the stars determine our fate has lost all intellectual currency. Hence there is no longer any need for the term “astronomical science.”
Critics of “economic sciences” sometimes refer to the development of a “pseudoscience” of economics, arguing that it uses the trappings of science, like dense mathematics, but only for show. For example, in his 2004 book Fooled by Randomness, Nassim Nicholas Taleb said of economic sciences: “You can disguise charlatanism under the weight of equations, and nobody can catch you since there is no such thing as a controlled experiment.”
But physics is not without such critics, too. In his 2004 book The Trouble with Physics: The Rise of String Theory, The Fall of a Science, and What Comes Next, Lee Smolin reproached the physics profession for being seduced by beautiful and elegant theories (notably string theory) rather than those that can be tested by experimentation. Similarly, in his 2007 book Not Even Wrong: The Failure of String Theory and the Search for Unity in Physical Law, Peter Woit accused physicists of much the same sin as mathematical economists are said to commit.
My belief is that economics is somewhat more vulnerable than the physical sciences to models whose validity will never be clear, because the necessity for approximation is much stronger than in the physical sciences, especially given that the models describe people rather than magnetic resonances or fundamental particles. People can just change their minds and behave completely differently. They even have neuroses and identity problems, complex phenomena that the field of behavioral economics is finding relevant to understanding economic outcomes.
But all the mathematics in economics is not, as Taleb suggests, charlatanism. Economics has an important quantitative side, which cannot be escaped. The challenge has been to combine its mathematical insights with the kinds of adjustments that are needed to make its models fit the economy’s irreducibly human element.
The advance of behavioral economics is not fundamentally in conflict with mathematical economics, as some seem to think, though it may well be in conflict with some currently fashionable mathematical economic models. And, while economics presents its own methodological problems, the basic challenges facing researchers are not fundamentally different from those faced by researchers in other fields. As economics develops, it will broaden its repertory of methods and sources of evidence, the science will become stronger, and the charlatans will be exposed. Read more at http://www.project-syndicate.org/commentary/robert-j--shilleron-whether-he-is-a-scientist#KJBGzzLDgWDHcMD1.99 |
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