2012年1月12日星期四

how to write an essay


guide to write a basic essay

http://lklivingston.tripod.com/essay/index.html



http://lklivingston.tripod.com/essay/body.html

Write the Introduction and Conclusion


Add the Finishing Touches

"Nothing can substitute for revision of your work. By reviewing what you have done, you can improve weak points that otherwise would be missed. Read and reread your paper."

2011年9月11日星期日

Kaldor–Hicks efficiency

Kaldor–Hicks efficiency, named for Nicholas Kaldor and John Hicks, also known as Kaldor–Hicks criterion, is a measure of economic efficiency that captures some of the intuitive appeal of Pareto efficiency, but has less stringent criteria and is hence applicable to more circumstances. Under Kaldor–Hicks efficiency, an outcome is considered more efficient if a Pareto optimal outcome can be reached by arranging sufficient compensation from those that are made better off to those that are made worse off so that all would end up no worse off than before.

规范法经济学的其中一个最重要的概念应当是“效率”。效率的含义是什么?对于经济学家而言,效率是一个工具概念。在普通道语言中,效率的一词通常是不特定的、发散的。为了理解经济学中关于效率的概念,我们会解释什么是帕雷托原则(Pareto principles)以及一个相关的概念卡尔多-希克斯效率。
除了解释效率的概念,我们将会进一步总结一下对这个概念的批评。虽然,很多经济学家在操作过程中,都假定“效率”的概念是没有争议的,但是,事实上,无论是经济学学科的内部还是外部都是充满争议的
在规范经济学有几个模糊的表达,但是,很多大多数规范经济学都是以效用作为一个基础的或者对于商品的衡量的概念。经济学家可能不同意效用的本质,效用与社会福利的关系,以及公共政策中福利的角色。但是,大多数经济家会赞同一个抽象的观点:在其他条件不变的情况下(ceteris paribus),更多的效用是一件好事情。
历史上,经济学中关于效用的解释与英国大哲学家边沁有关。边沁用快乐来定义“效用”。边沁认为,法律和政策应该用快乐的累积(hedonic calculus)来衡量,最好的政策产生最大多数的快感(hedons)——单位快乐。但是,边沁的理论并没有为经济学科学提供一个可以操作的依据。因为没有一个可以度量快感的方法。这个假设被经济学和心理学的研究所逐步削弱,他们用“幸福”(happiness)这个可以操作的概念来取代了快感的标准。
当代经济学用偏好函数来表述效用—— 即个体对于状态的主观评价。如果个体I 偏好于状态X(state of affair X),较之于状态Y,那么X 要较之于Y带来更多的效用
我们如何测量偏好?经济学提出了两种不同的理论,一种是基数效用理论,一种是序数效用理论。序数效用理论是把个体对于不同状态(states of affairs)的喜好的排序,序数函数告诉我们,个体I 对于可能的X的偏好大于可能的Y的偏好,但是,它没有告诉我们,X较之于Y 的好的程度。基数效用函数通过一个真实的数据来表述每个状态。如果,我们假定效用函数用“单位效用”表述,那么I 的效用就可以用分值来表述,比如说,在P状态,I的效用为80个单位效用,在Q状态下,I 的效用为120个单位效用。
基数效用和序数效用的区别对于功利主义(utilitarianism)来说是非常重要的,最少在某些解释方面。作为一个评判的理论,功利主义utilitarianism可以被认为这样一个约定的规范:一个行动是最优的,如果它带所带来的效用在所有的可能行动中是最大的。由于技术上的原因,功利主义需要基数和个体之间的比较。但是,不管是基数还是序数都存在问题。甚至对于个体的基数效用的比较都是困难的。(为什么?)
在不同个体之间的效用比较就更加困难。我们如何比较某甲源于观赏漂亮的照片所获得效用与某乙在做义工所带来效用。这些例子表明,个体之间的效用比较的不可通约性(incommensurability)。这意味着,偏好不可能用相同的尺度进行比较。基数效用和序数效用的面对的困境终结了福利经济学的历史。
帕雷托原则在这种情况下产生了。假定我们所获得个体效用信息是序数但是,不可以比较的。换言之,个体可以对事情状态进行排序,但是我们(分析家或者政策制订者)不能比较个体之间的效用。弱的帕雷托原则建议,P状态好于Q状态,如果每个人都把P排在Q的前面。弱的帕雷托原则似乎并没有得到很多的改进,因为对于全体一致的情况是很少见的。
强的帕雷托原则建议:P状态好于Q状态,如果至少有一个人把P排在Q前面,而没有人把Q排在P前面。或者更通俗地说,强的帕雷托认为,其中一个人受益而没一个人受损,这种状态就是好的。不同于弱的帕雷托原则,强的帕雷托原则可以产生相对稳定的结论。
因为帕雷托效率假定不存在负的外部性,作为一个规范的概念有很多的局限性,如果甚至一个人将会受损,如果从状态P到状态Q,这种转换不是帕雷托效率的。这样,如果帕雷托效率仅仅是一个规范的标准对于法律经济学来说,结果将会变成对于很多法律问题都似乎什么都没有什么,也就没有办法提供建议了。比如,很多环境法的问题(特别是考虑交易成本的情况下)
卡尔多西克斯标准是规范经济分析一个扩展。它的基本思路是,我们考虑一个存在外部性的环境,比如,污染损害了第三方利益。我们假定市场没有办法得到帕雷托效率结果。这个假定是准确的,因为高的交易成本的存在。在污染这个例子中,关涉到很多人的利益,产生了大量的交易成本。有可能与现实不同的情况是,我们可以假定零交易成本的情况。然后,我们问,什么样的结果会产生?如果受到外部性侵害的个体进入到帕雷托效率的谈判,对于他们的损失进行补偿,结果是卡尔多效率的(如果没有交易成本将会是帕雷托效率)。卡尔多标准扩展了规范法经济学,把交易成本和外部性等因素纳入统一分析。

2009年3月20日星期五

Do not let the ‘cure’ destroy capitalism

Do not let the ‘cure’ destroy capitalism
By Gary Becker and Kevin Murphy
Published: March 19 2009 20:04 Last updated: March 19 2009 20:04
Capitalism has been wounded by the global recession, which unfortunately will get worse before it gets better. As governments continue to determine how many restrictions to place on markets, especially financial markets, the destruction of wealth from the recession should be placed in the context of the enormous creation of wealth and improved well-being during the past three decades. Financial and other reforms must not risk destroying the source of these gains in prosperity.Consider the following extraordinary statistics about the performance of the world economy since 1980. World real gross domestic product grew by about 145 per cent from 1980 to 2007, or by an average of roughly 3.4 per cent a year. The so-called capitalist greed that motivated business people and ambitious workers helped hundreds of millions to climb out of grinding poverty. The role of capitalism in creating wealth is seen in the sharp rise in Chinese and Indian incomes after they introduced market-based reforms (China in the late 1970s and India in 1991). Global health, as measured by life expectancy at different ages, has also risen rapidly, especially in lower-income countries. Of course, the performance of capitalism must include this recession and other recessions along with the glory decades. Even if the recession is entirely blamed on capitalism, and it deserves a good share of the blame, the recession-induced losses pale in comparison with the great accomplishments of prior decades. Suppose, for example, that the recession turns into a depression, where world GDP falls in 2008-10 by 10 per cent, a pessimistic assumption. Then the net growth in world GDP from 1980 to 2010 would amount to 120 per cent, or about 2.7 per cent a year over this 30-year period. This allowed real per capita incomes to rise by almost 40 per cent even though world population grew by roughly 1.6 per cent a year over the same period.Therefore, in devising reforms that aim to reduce the likelihood of future severe contractions, the accomplishments of capitalism should be appreciated. Governments should not so hamper markets that they are prevented from bringing rapid growth to the poor economies of Africa, Asia and elsewhere that have had limited participation in the global economy. New economic policies that try to speed up recovery should follow the first principle of medicine: do no harm. This runs counter to a common but mistaken view, even among many free-market proponents, that it is better to do something to try to help the economy than to do nothing. Most interventions, including random policies, by their very nature would hurt rather than help, in large part by adding to the uncertainty and risk that are already so prominent during this contraction.Government reactions have demonstrated the danger that interventions designed to help can exacerbate the problem. Even though we had well-qualified policymakers, we have gone from error to error since August 2007.The policies of the Bush and Obama administrations violate the “do no harm” principle. Interventions by the US Treasury in financial markets have added to the uncertainty and slowed market responses that would help stabilise and recapitalise the system. The government has overridden contracts and rewarded many of those whose poor decisions helped create the mess. It proposes to override even more contracts. As a result of the Treasury’s actions, we face further distorted decision-making as government ownership of big financial institutions threatens to substitute political agendas for business judgments in running these companies. While such dramatic measures may be expedient, they are likely to have serious adverse consequences.These problems are symptomatic of three basic flaws in the current approach to the crisis. They are an overly broad diagnosis of the problem, a misconception that market failures are readily overcome by government solutions and a failure to focus on the long-run costs of current actions.The rush to “solve” the problems of the crisis has opened the door to government actions on many fronts. Many of these have little or nothing to do with the crisis or its causes. For example, the Obama administration has proposed sweeping changes to labour market policies to foster unionisation and a more centralised setting of wages, even though the relative freedom of US labour markets in no way contributed to the crisis and would help to keep it short. Similarly, the backlash against capitalism and “greed” has been used to justify more antitrust scrutiny, greater regulation of a range of markets, and an expansion of price controls for healthcare and pharmaceuticals. The crisis has led to a bail-out of the US car industry and a government role in how it will be run. Even one of the most discredited ideas, protectionism, has gained support under the guise of stimulating the economy. Such policies would be a mistake. They make no more sense today than they did a few years ago and could take a long time to reverse.The failure of financial innovations such as securities backed by subprime mortgages, problems caused by risk models that ignored the potential for steep falls in house prices and the overload of systemic risk represent clear market failures, although innovations in finance also contributed to the global boom over the past three decades.The people who made mistakes lost, and many lost big. Institutions that made bad loans and investments had large declines in their wealth, while investors that funded these institutions without proper scrutiny have seen their wealth cut in half or much more. Households that overextended themselves have also been badly hurt.Given the losses, actors in these markets have a strong incentive to correct their mistakes the next time. In this respect, many government actions have been counterproductive, shielding actors from the consequences of their actions and preventing private sector adjustments. The uncertainty from muddled Treasury policy on bank capital and ownership structure, the willingness of the government to change mortgage and debt contracts unilaterally and the uncertain nature of future regulation and subsidies help prevent greater private recapitalisation. Rather than solving problems, such policies tend to prolong them.The US stimulus bill falls into the same category. This package is partly based on the belief that government spending is required to stimulate the economy because private spending would be insufficient. The focus on government solutions is particularly disappointing given its poor record in dealing with crises in the US and many other countries, such as the aftermath of hurricane Katrina and failure effectively to prosecute the war in Iraq.The claim that the crisis was due to insufficient regulation is also unconvincing. For example, commercial banks have been more regulated than most other financial institutions, yet they performed no better, and in many ways worse. Regulators got caught up in the same bubble mentality as investors and failed to use the regulatory authority available to them.Output, employment and earnings have all been hit by the crisis and will get worse before they get better. Nevertheless, even big downturns represent pauses in long-run progress if we keep the engines of long-term growth in place. This growth depends on investment in human and physical capital and the production of new knowledge. That requires a stable economic environment. Uncertainty about the scope of regulation is likely to have the unintended consequence of making those investments more risky. The Great Depression induced a massive worldwide retreat from capitalism, and an embrace of socialism and communism that continued into the 1960s. It also fostered a belief that the future lay in government management of the economy, not in freer markets. The result was generally slow growth during those decades in most of the undeveloped world, including China, the Soviet bloc nations, India and Africa. Partly owing to the collapse of the housing and stock markets, hostility to business people and capitalism has grown sharply again. Yet a world that is mainly capitalistic is the “only game in town” that can deliver further large increases in wealth and health to poor as well as rich nations. We hope our leaders do not deviate far from a market-oriented global economic system. To do so would risk damaging a system that has served us well for 30 years.The writers are professors of economics and the University of Chicago and senior fellows at the Hoover Institution. Gary Becker was awarded the 1992 Nobel prize in economics and Kevin Murphy was awarded the Clark Medal in 1997. To join the debate go to www.ft.com/capitalismblogCopyright The Financial Times Limited 2009

2009年3月16日星期一

Capitalism Beyond the Crisis

http://www.nybooks.com/articles/22490
Capitalism Beyond the Crisis
By Amartya Sen
1.
2008 was a year of crises. First, we had a food crisis, particularly threatening to poor consumers, especially in Africa. Along with that came a record increase in oil prices, threatening all oil-importing countries. Finally, rather suddenly in the fall, came the global economic downturn, and it is now gathering speed at a frightening rate. The year 2009 seems likely to offer a sharp intensification of the downturn, and many economists are anticipating a full-scale depression, perhaps even one as large as in the 1930s. While substantial fortunes have suffered steep declines, the people most affected are those who were already worst off.
The question that arises most forcefully now concerns the nature of capitalism and whether it needs to be changed. Some defenders of unfettered capitalism who resist change are convinced that capitalism is being blamed too much for short-term economic problems—problems they variously attribute to bad governance (for example by the Bush administration) and the bad behavior of some individuals (or what John McCain described during the presidential campaign as "the greed of Wall Street"). Others do, however, see truly serious defects in the existing economic arrangements and want to reform them, looking for an alternative approach that is increasingly being called "new capitalism."
The idea of old and new capitalism played an energizing part at a symposium called "New World, New Capitalism" held in Paris in January and hosted by the French president Nicolas Sarkozy and the former British prime minister Tony Blair, both of whom made eloquent presentations on the need for change. So did German Chancellor Angela Merkel, who talked about the old German idea of a "social market"—one restrained by a mixture of consensus-building policies—as a possible blueprint for new capitalism (though Germany has not done much better in the recent crisis than other market economies).
Ideas about changing the organization of society in the long run are clearly needed, quite apart from strategies for dealing with an immediate crisis. I would separate out three questions from the many that can be raised. First, do we really need some kind of "new capitalism" rather than an economic system that is not monolithic, draws on a variety of institutions chosen pragmatically, and is based on social values that we can defend ethically? Should we search for a new capitalism or for a "new world"—to use the other term mentioned at the Paris meeting—that would take a different form?
The second question concerns the kind of economics that is needed today, especially in light of the present economic crisis. How do we assess what is taught and championed among academic economists as a guide to economic policy—including the revival of Keynesian thought in recent months as the crisis has grown fierce? More particularly, what does the present economic crisis tell us about the institutions and priorities to look for? Third, in addition to working our way toward a better assessment of what long-term changes are needed, we have to think—and think fast—about how to get out of the present crisis with as little damage as possible.
2.
What are the special characteristics that make a system indubitably capitalist—old or new? If the present capitalist economic system is to be reformed, what would make the end result a new capitalism, rather than something else? It seems to be generally assumed that relying on markets for economic transactions is a necessary condition for an economy to be identified as capitalist. In a similar way, dependence on the profit motive and on individual rewards based on private ownership are seen as archetypal features of capitalism. However, if these are necessary requirements, are the economic systems we currently have, for example, in Europe and America, genuinely capitalist?
All affluent countries in the world—those in Europe, as well as the US, Canada, Japan, Singapore, South Korea, Australia, and others—have, for quite some time now, depended partly on transactions and other payments that occur largely outside markets. These include unemployment benefits, public pensions, other features of social security, and the provision of education, health care, and a variety of other services distributed through nonmarket arrangements. The economic entitlements connected with such services are not based on private ownership and property rights.
Also, the market economy has depended for its own working not only on maximizing profits but also on many other activities, such as maintaining public security and supplying public services—some of which have taken people well beyond an economy driven only by profit. The creditable performance of the so-called capitalist system, when things moved forward, drew on a combination of institutions—publicly funded education, medical care, and mass transportation are just a few of many—that went much beyond relying only on a profit-maximizing market economy and on personal entitlements confined to private ownership.
Underlying this issue is a more basic question: whether capitalism is a term that is of particular use today. The idea of capitalism did in fact have an important role historically, but by now that usefulness may well be fairly exhausted.
For example, the pioneering works of Adam Smith in the eighteenth century showed the usefulness and dynamism of the market economy, and why—and particularly how—that dynamism worked. Smith's investigation provided an illuminating diagnosis of the workings of the market just when that dynamism was powerfully emerging. The contribution that The Wealth of Nations, published in 1776, made to the understanding of what came to be called capitalism was monumental. Smith showed how the freeing of trade can very often be extremely helpful in generating economic prosperity through specialization in production and division of labor and in making good use of economies of large scale.
Those lessons remain deeply relevant even today (it is interesting that the impressive and highly sophisticated analytical work on international trade for which Paul Krugman received the latest Nobel award in economics was closely linked to Smith's far-reaching insights of more than 230 years ago). The economic analyses that followed those early expositions of markets and the use of capital in the eighteenth century have succeeded in solidly establishing the market system in the corpus of mainstream economics.
However, even as the positive contributions of capitalism through market processes were being clarified and explicated, its negative sides were also becoming clear—often to the very same analysts. While a number of socialist critics, most notably Karl Marx, influentially made a case for censuring and ultimately supplanting capitalism, the huge limitations of relying entirely on the market economy and the profit motive were also clear enough even to Adam Smith. Indeed, early advocates of the use of markets, including Smith, did not take the pure market mechanism to be a freestanding performer of excellence, nor did they take the profit motive to be all that is needed.
Even though people seek trade because of self-interest (nothing more than self-interest is needed, as Smith famously put it, in explaining why bakers, brewers, butchers, and consumers seek trade), nevertheless an economy can operate effectively only on the basis of trust among different parties. When business activities, including those of banks and other financial institutions, generate the confidence that they can and will do the things they pledge, then relations among lenders and borrowers can go smoothly in a mutually supportive way. As Adam Smith wrote:
When the people of any particular country have such confidence in the fortune, probity, and prudence of a particular banker, as to believe that he is always ready to pay upon demand such of his promissory notes as are likely to be at any time presented to him; those notes come to have the same currency as gold and silver money, from the confidence that such money can at any time be had for them.[1]
Smith explained why sometimes this did not happen, and he would not have found anything particularly puzzling, I would suggest, in the difficulties faced today by businesses and banks thanks to the widespread fear and mistrust that is keeping credit markets frozen and preventing a coordinated expansion of credit.
It is also worth mentioning in this context, especially since the "welfare state" emerged long after Smith's own time, that in his various writings, his overwhelming concern—and worry—about the fate of the poor and the disadvantaged are strikingly prominent. The most immediate failure of the market mechanism lies in the things that the market leaves undone. Smith's economic analysis went well beyond leaving everything to the invisible hand of the market mechanism. He was not only a defender of the role of the state in providing public services, such as education, and in poverty relief (along with demanding greater freedom for the indigents who received support than the Poor Laws of his day provided), he was also deeply concerned about the inequality and poverty that might survive in an otherwise successful market economy.
Lack of clarity about the distinction between the necessity and sufficiency of the market has been responsible for some misunderstandings of Smith's assessment of the market mechanism by many who would claim to be his followers. For example, Smith's defense of the food market and his criticism of restrictions by the state on the private trade in food grains have often been interpreted as arguing that any state interference would necessarily make hunger and starvation worse.
But Smith's defense of private trade only took the form of disputing the belief that stopping trade in food would reduce the burden of hunger. That does not deny in any way the need for state action to supplement the operations of the market by creating jobs and incomes (e.g., through work programs). If unemployment were to increase sharply thanks to bad economic circumstances or bad public policy, the market would not, on its own, recreate the incomes of those who have lost their jobs. The new unemployed, Smith wrote, "would either starve, or be driven to seek a subsistence either by begging, or by the perpetration perhaps of the greatest enormities," and "want, famine, and mortality would immediately prevail...."[2] Smith rejects interventions that exclude the market—but not interventions that include the market while aiming to do those important things that the market may leave undone.
Smith never used the term "capitalism" (at least so far as I have been able to trace), but it would also be hard to carve out from his works any theory arguing for the sufficiency of market forces, or of the need to accept the dominance of capital. He talked about the importance of these broader values that go beyond profits in The Wealth of Nations, but it is in his first book, The Theory of Moral Sentiments, which was published exactly a quarter of a millennium ago in 1759, that he extensively investigated the strong need for actions based on values that go well beyond profit seeking. While he wrote that "prudence" was "of all the virtues that which is most useful to the individual," Adam Smith went on to argue that "humanity, justice, generosity, and public spirit, are the qualities most useful to others."[3]
Smith viewed markets and capital as doing good work within their own sphere, but first, they required support from other institutions—including public services such as schools—and values other than pure profit seeking, and second, they needed restraint and correction by still other institutions—e.g., well-devised financial regulations and state assistance to the poor—for preventing instability, inequity, and injustice. If we were to look for a new approach to the organization of economic activity that included a pragmatic choice of a variety of public services and well-considered regulations, we would be following rather than departing from the agenda of reform that Smith outlined as he both defended and criticized capitalism.
3.
Historically, capitalism did not emerge until new systems of law and economic practice protected property rights and made an economy based on ownership workable. Commercial exchange could not effectively take place until business morality made contractual behavior sustainable and inexpensive—not requiring constant suing of defaulting contractors, for example. Investment in productive businesses could not flourish until the higher rewards from corruption had been moderated. Profit-oriented capitalism has always drawn on support from other institutional values.
The moral and legal obligations and responsibilities associated with transactions have in recent years become much harder to trace, thanks to the rapid development of secondary markets involving derivatives and other financial instruments. A subprime lender who misleads a borrower into taking unwise risks can now pass off the financial assets to third parties—who are remote from the original transaction. Accountability has been badly undermined, and the need for supervision and regulation has become much stronger.
And yet the supervisory role of government in the United States in particular has been, over the same period, sharply curtailed, fed by an increasing belief in the self-regulatory nature of the market economy. Precisely as the need for state surveillance grew, the needed supervision shrank. There was, as a result, a disaster waiting to happen, which did eventually happen last year, and this has certainly contributed a great deal to the financial crisis that is plaguing the world today. The insufficient regulation of financial activities has implications not only for illegitimate practices, but also for a tendency toward overspeculation that, as Adam Smith argued, tends to grip many human beings in their breathless search for profits.
Smith called the promoters of excessive risk in search of profits "prodigals and projectors"—which is quite a good description of issuers of subprime mortgages over the past few years. Discussing laws against usury, for example, Smith wanted state regulation to protect citizens from the "prodigals and projectors" who promoted unsound loans:
A great part of the capital of the country would thus be kept out of the hands which were most likely to make a profitable and advantageous use of it, and thrown into those which were most likely to waste and destroy it.[4]
The implicit faith in the ability of the market economy to correct itself, which is largely responsible for the removal of established regulations in the United States, tended to ignore the activities of prodigals and projectors in a way that would have shocked Adam Smith.
The present economic crisis is partly generated by a huge overestimation of the wisdom of market processes, and the crisis is now being exacerbated by anxiety and lack of trust in the financial market and in businesses in general—responses that have been evident in the market reactions to the sequence of stimulus plans, including the $787 billion plan signed into law in February by the new Obama administration. As it happens, these problems were already identified in the eighteenth century by Smith, even though they have been neglected by those who have been in authority in recent years, especially in the United States, and who have been busy citing Adam Smith in support of the unfettered market.
4.
While Adam Smith has recently been much quoted, even if not much read, there has been a huge revival, even more recently, of John Maynard Keynes. Certainly, the cumulative downturn that we are observing right now, which is edging us closer to a depression, has clear Keynesian features; the reduced incomes of one group of persons has led to reduced purchases by them, in turn causing a further reduction in the income of others.
However, Keynes can be our savior only to a very partial extent, and there is a need to look beyond him in understanding the present crisis. One economist whose current relevance has been far less recognized is Keynes's rival Arthur Cecil Pigou, who, like Keynes, was also in Cambridge, indeed also in Kings College, in Keynes's time. Pigou was much more concerned than Keynes with economic psychology and the ways it could influence business cycles and sharpen and harden an economic recession that could take us toward a depression (as indeed we are seeing now). Pigou attributed economic fluctuations partly to "psychological causes" consisting of
variations in the tone of mind of persons whose action controls industry, emerging in errors of undue optimism or undue pessimism in their business forecasts.[5]
It is hard to ignore the fact that today, in addition to the Keynesian effects of mutually reinforced decline, we are strongly in the presence of "errors of...undue pessimism." Pigou focused particularly on the need to unfreeze the credit market when the economy is in the grip of excessive pessimism:
Hence, other things being equal, the actual occurrence of business failures will be more or less widespread, according [to whether] bankers' loans, in the face of crisis of demands, are less or more readily obtainable.[6]
Despite huge injections of fresh liquidity into the American and European economies, largely from the government, the banks and financial institutions have until now remained unwilling to unfreeze the credit market. Other businesses also continue to fail, partly in response to already diminished demand (the Keynesian "multiplier" process), but also in response to fear of even less demand in the future, in a climate of general gloom (the Pigovian process of infectious pessimism).
One of the problems that the Obama administration has to deal with is that the real crisis, arising from financial mismanagement and other transgressions, has become many times magnified by a psychological collapse. The measures that are being discussed right now in Washington and elsewhere to regenerate the credit market include bailouts—with firm requirements that subsidized financial institutions actually lend—government purchase of toxic assets, insurance against failure to repay loans, and bank nationalization. (The last proposal scares many conservatives just as private control of the public money given to the banks worries people concerned about accountability.) As the weak response of the market to the administration's measures so far suggests, each of these policies would have to be assessed partly for their impact on the psychology of businesses and consumers, particularly in America.
5.
The contrast between Pigou and Keynes is relevant for another reason as well. While Keynes was very involved with the question of how to increase aggregate income, he was relatively less engaged in analyzing problems of unequal distribution of wealth and of social welfare. In contrast, Pigou not only wrote the classic study of welfare economics, but he also pioneered the measurement of economic inequality as a major indicator for economic assessment and policy.[7] Since the suffering of the most deprived people in each economy—and in the world—demands the most urgent attention, the role of supportive cooperation between business and government cannot stop only with mutually coordinated expansion of an economy. There is a critical need for paying special attention to the underdogs of society in planning a response to the current crisis, and in going beyond measures to produce general economic expansion. Families threatened with unemployment, with lack of medical care, and with social as well as economic deprivation have been hit particularly hard. The limitations of Keynesian economics to address their problems demand much greater recognition.
A third way in which Keynes needs to be supplemented concerns his relative neglect of social services—indeed even Otto von Bismarck had more to say on this subject than Keynes. That the market economy can be particularly bad in delivering public goods (such as education and health care) has been discussed by some of the leading economists of our time, including Paul Samuelson and Kenneth Arrow. (Pigou too contributed to this subject with his emphasis on the "external effects" of market transactions, where the gains and losses are not confined only to the direct buyers or sellers.) This is, of course, a long-term issue, but it is worth noting in addition that the bite of a downturn can be much fiercer when health care in particular is not guaranteed for all.
For example, in the absence of a national health service, every lost job can produce a larger exclusion from essential health care, because of loss of income or loss of employment-related private health insurance. The US has a 7.6 percent rate of unemployment now, which is beginning to cause huge deprivation. It is worth asking how the European countries, including France, Italy, and Spain, that lived with much higher levels of unemployment for decades, managed to avoid a total collapse of their quality of life. The answer is partly the way the European welfare state operates, with much stronger unemployment insurance than in America and, even more importantly, with basic medical services provided to all by the state.
The failure of the market mechanism to provide health care for all has been flagrant, most noticeably in the United States, but also in the sharp halt in the progress of health and longevity in China following its abolition of universal health coverage in 1979. Before the economic reforms of that year, every Chinese citizen had guaranteed health care provided by the state or the cooperatives, even if at a rather basic level. When China removed its counterproductive system of agricultural collectives and communes and industrial units managed by bureaucracies, it thereby made the rate of growth of gross domestic product go up faster than anywhere else in the world. But at the same time, led by its new faith in the market economy, China also abolished the system of universal health care; and, after the reforms of 1979, health insurance had to be bought by individuals (except in some relatively rare cases in which the state or some big firms provide them to their employees and dependents). With this change, China's rapid progress in longevity sharply slowed down.
This was problem enough when China's aggregate income was growing extremely fast, but it is bound to become a much bigger problem when the Chinese economy decelerates sharply, as it is currently doing. The Chinese government is now trying hard to gradually reintroduce health insurance for all, and the US government under Obama is also committed to making health coverage universal. In both China and the US, the rectifications have far to go, but they should be central elements in tackling the economic crisis, as well as in achieving long-term transformation of the two societies.
6.
The revival of Keynes has much to contribute both to economic analysis and to policy, but the net has to be cast much wider. Even though Keynes is often seen as a kind of a "rebel" figure in contemporary economics, the fact is that he came close to being the guru of a new capitalism, who focused on trying to stabilize the fluctuations of the market economy (and then again with relatively little attention to the psychological causes of business fluctuations). Even though Smith and Pigou have the reputation of being rather conservative economists, many of the deep insights about the importance of nonmarket institutions and nonprofit values came from them, rather than from Keynes and his followers.
A crisis not only presents an immediate challenge that has to be faced. It also provides an opportunity to address long-term problems when people are willing to reconsider established conventions. This is why the present crisis also makes it important to face the neglected long-term issues like conservation of the environment and national health care, as well as the need for public transport, which has been very badly neglected in the last few decades and is also so far sidelined—as I write this article—even in the initial policies announced by the Obama administration. Economic affordability is, of course, an issue, but as the example of the Indian state of Kerala shows, it is possible to have state-guaranteed health care for all at relatively little cost. Since the Chinese dropped universal health insurance in 1979, Kerala—which continues to have it—has very substantially overtaken China in average life expectancy and in indicators such as infant mortality, despite having a much lower level of per capita income. So there are opportunities for poor countries as well.
But the largest challenges face the United States, which already has the highest level of per capita expenditure on health among all countries in the world, but still has a relatively low achievement in health and has more than forty million people with no guarantee of health care. Part of the problem here is one of public attitude and understanding. Hugely distorted perceptions of how a national health service works need to be corrected through public discussion. For example, it is common to assume that no one has a choice of doctors in a European national health service, which is not at all the case.
There is, however, also a need for better understanding of the options that exist. In US discussions of health reform, there has been an overconcentration on the Canadian system—a system of public health care that makes it very hard to have private medical care—whereas in Western Europe the national health services provide care for all but also allow, in addition to state coverage, private practice and private health insurance, for those who have the money and want to spend it this way. It is not clear just why the rich who can freely spend money on yachts and other luxury goods should not be allowed to spend it on MRIs or CT scans instead. If we take our cue from Adam Smith's arguments for a diversity of institutions, and for accommodating a variety of motivations, there are practical measures we can take that would make a huge difference to the world in which we live.
The present economic crises do not, I would argue, call for a "new capitalism," but they do demand a new understanding of older ideas, such as those of Smith and, nearer our time, of Pigou, many of which have been sadly neglected. What is also needed is a clearheaded perception of how different institutions actually work, and of how a variety of organizations—from the market to the institutions of the state—can go beyond short-term solutions and contribute to producing a more decent economic world.
—February 25, 2009
Notes

2009年1月20日星期二

行为经济学和实验经济学的基础—2002年诺贝尔经济学奖获得者思想介评

2002年诺贝尔经济学奖已经在10月9日公布。两位获奖者分别为美国普林斯顿大学的丹尼尔.卡尼曼(Daniel Kahneman)和乔治.梅森大学的弗农.史密斯(Vernon Smith)。瑞典皇家科学院在宣布他们的主要贡献时指出,丹尼尔,卡尼曼是“因为将心理学研究结合到经济学中,特别是关于不确定条件下的人类判断和决策”;弗农.史密斯是“因为将实验室实验作为经验经济分析的一种工具,特别是在可选择的市场机制研究方面。”这说明行为经济学和实验经济学作为经济学重要分支的地位得到确认和加强。本文主要对二者的思想进行介绍,并作简单评论。
  一、行为经济学的基础
  20世纪中叶,爱德华(Edwards)提出将行为决定作为心理学研究的主题,并确定了研究的程序,西蒙(Simon)提出了基于有限理性的信息处理和决策方法。但是真正对此展开深入研究的是丹尼尔.卡尼曼和阿莫斯.特韦尔斯基(Amos Tversky)。尽管卡尼曼的研究还坚持认知心理学的传统,但主要还是经济学的。他的大多数论文发表在经济学杂志上,其引用率在经济学领域一直非常高。如果说在经济学和心理学传统规则中存在联系障碍,目前许多研究致力于在二者之间建立起联系方法:一种是实验的方法,另一种是理论建模的方法。
  1.不确定条件下的判断:启发法和偏见
  卡尼曼和特韦尔斯基发现,不确定条件下的判断与传统经济理论对理性的假定存在系统差别。他们早期的大多数研究强调的一个基本观念是,人们一般不能完全分析包含经济和概率判断的情形。在这些情况下,人类决策依靠某些捷径或启发法,这些方法有时存在系统性偏差。
  —个基本的偏差是个人似乎运用小数法则,将同样的概率分布归结为小样本和大样本中的经验平均值,从而就违反了概率论中的大数法则。例如在一个著名的实验中发现,参与实验者认为在给定的一天中在大医院和小医院中出生的小孩中男孩的比例高于60%的概率相等。一般情况下,人们似乎没有意识到随着样本的增大,随机变量对平均数的偏离是不断下降的。更精确地说,根据统计上的大数法则,随机变量大样本独立观察平均值的概率分布在随机变量的期望值附近集中,并且样本平均值的偏差随着样本规模的增大会趋近于零。根据心理学的小数法则。人们相信小样本的平均值也会向随机变量期望值附近集中分布。
  小数规则的一个例子是,如果一位投资者观察到一位基金经理在过去两年中的投资业绩好于平均情况,就会得出这位经理要比一般经理优秀的结论。然而真实的统计含义非常微弱。一个相关的例子就是赌徒谬误,许多人都希望随机的第二次抽彩与第一次没有关系,即使抽彩从统计上看是相互独立的。在投掷硬币游戏中,如果前几次大多数出现正面,那么很多人就相信下一次投掷很可能出现反面。最近的研究描述了小数规则对经济决定的重要作用(Rabin,2002)。
  小数法则与典型法,即卡尼曼和特韦尔斯基发现的作为人类判断重要因素的启发法相关。他们在几个重要实验中阐明了这种启发法的功能。参与实验者要求根据描述对一群人进行归类,比如说分成“商人”和“议员”。从给定的人群中随机找出一个进行描述,其特征包括“对政治感兴趣,喜欢参与争论,热衷于出现在媒体中”,大多数人会认为这是个议员,即使选定的人群中商人的比例更高这一事实使该人更可能是一个商人。他们进一步检验了这一观察到结果。他们做了一个实验。在这个实验中,某些参与实验者拥有关于人群组成比例的明确信息。一个方案是要被分类的人群是从30%工程师和70%律师组成的一群人中抽取的;另一个方案中比例相反。结果表明这种差别对参与实验者的判断没有影响。
  施莱佛(Shleifer)认为,小数法则和典型法可以解释金融市场上的某些反常(Shleifer,2000)。例如对股票价格的过度敏感可能是投资者对利好新闻短期刺激过度反应的结果。
  概率判断另一个共同偏见是有效性,人们通过简化特定事例判断概率。结果是人们更倾向于明显的或便于记忆的信息(Tversky and Kahneman,1973),认知心理学的一个一般发现是,与不熟悉的信息相比,熟悉的信息更便于记忆,也相信其更加真实,相关。这样,熟悉和有效就对精确和相关起到提示作用。因此,媒体中某些信息极少重复,如果不考虑精确性,人们就会更容易认为其有效并因此而产生错误认识。
  这一人类判断的证据表明,人们的推理向概率论的基本法则提出了系统挑战。卡尼曼的研究阐明了这一点,向传统经济论基础之一的经验有效性提出了非常严肃的质疑。
  2.不确定条件下的决策:预测理论
  有证据表明,不仅不确定条件下的判断,而且决策也与传统经济理论产生了系统背离。特别是,不确定条件下的许多决策与预期效用理论的预测发生了分歧。
  莫里斯.阿莱首先对不确定条件下决策的冯.诺伊曼—摩根斯坦一萨维奇(Von Neumann—Morgenstern—Savage)预期效用函数提出了质疑,并提出了“阿莱悖沦(Allais Paradox)”。例如许多人宁可选择3000美元的固定收益,而不愿意以80%的概率获得4000美元,20%的概率一无所获。然而,在同样一群人中,有人宁愿以20%的概率获得4000美元,而不愿以25%的概率获得3000美元,尽管两种情况下概率下降的幅度相同,都是0.25。这种偏好对所谓的预期效用理论替代公理提出了挑战。卡尼曼提出了偏离预期效用预测的大量例证。
  一个令人兴奋的发现是,比起绝对条件下的结果,人们通常对结果偏离某些非连续偏好水平的方式更敏感。这种更侧重变化而不是水平的现象可能与认知心理学有关,即认为人类对外部条件,比如温度的变化要比其水平值更敏感。
  然而,与偏好水平相关,对同样大小的收益和损失产生的影响,人们似乎认为损失的影响更大一些。特韦尔斯基和卡尼曼估计,适当损失造成的负面影响大概是同样收益正面影响的两倍,即人们的偏好更倾向于(局部)厌恶损失。对一次小的赌博来说,人们宁愿选择保持现状,也不愿以50%的概率赚取12美元,50%的概率损失10美元。根据传统经济理论,这与大额收益与损失下的隐含偏好不同。对于巨额损失,人们明显是个风险喜好者,这个一般发现与风险厌恶的传统假定明显不符。例如,卡尼曼和特韦尔斯基发现,在10个人中,7个人会选择以25%的概率损失6000美元,也不愿选择以25%的概率损失4000美元,25%的概率损失2000美元。因为两种抽签下预期损失的货币值相同,第二种情况只不过是第一种情况的平分。在传统的风险厌恶假定下,这两者应该没有差别。
  卡尼曼和特韦尔斯基给出了他们的解释。他们认为,预期效用理论是公理,而他们的预测理论只是一个描述(Kahneman and Tversky,1979)。这是通过经验观察以归纳的方式提出来的,而不是在一系列公理的基础上演绎出的。后来,他们认为两种理论实际上都是必需的:预期效用理论刻画理性行为,而预测理论描述实际行为(Tversky and Kahneman.1986)。尽管预期效用理论在某些明显的简单决定问题中对现实选择给出了一个精确描述,但是现实生活中的决定问题非常复杂,这需要关于行为的更加丰富的模型。
  预测理论提出了几个在传统经济理论中表现反常的规则:人们在购买小额物品时宁可驱车很远节省几个美元,而不愿在大额购买中驱车同样路程节省更多货币。
  总之,卡尼曼及其同事的经验研究表明了不确定条件下的几个选择规则,并且在预测理论中体现出来的思想对解释这些规则做出了重要贡献。卡尼曼的研究给经济学家提供了新的视角,并且在随后的模型建立中通过改变对实际决策者所犯一般错误的决策分析提供了工具。预测理论的进一步拓展,即著名的累计预测理论(Tversky and Kahneman,1992)指出了传统版本的缺陷。而且累计预测理论还要求对大量结果进行预测,并与随机领域一致。
  相对于预期效用理论,预测理论向精确描述不确定条件下个人行为迈出了重要一步。现在它已经形成了这个领域应用经验研究的基础。
  二、实验经济学的基础
  直到最近以来,经济学还被看作是一门不可实验的科学。主流观点认为,经济学家“不能从事化学家或生物学家的控制下的实验,因为他们不易控制其他重要因素。他们像天文学家和气象学家一样,一般只能限于以观察为主。”但是几年之后,主流观点发生了变化,尽管经济学实验存在各种各样的困难,但是“经济学家越来越依赖实验来解释经济行为”。
  最早的实验经济学研究,有人认为至少可以追溯到1738年伯努利(Bernoulli)所进行的有关“匹兹堡悖论”的实验(余剑梅,1999)。但是近期的研究主要是从张伯仑(Chamberlin)1948年的实验开始,其目的是要检验完全竞争的新古典理论(Chamberlin,1948);1994年诺贝尔经济学奖获得者泽尔滕(Reinhard Selten)等曾利用实验方法研究寡头市场的价格形成(Sauerman and Selten,1959);纳什等人曾经利用实验方法检验博弈论的预测力(Kalish、Milnor、Nash and Nehrig,1954);另外,西格尔(Siegel)和富莱克(Fouraker)也曾作过讨价还价实验的研究(Siegel and Fouraker,1960;Fouraker and Siegel,1963)。
  然而,对实验经济学主要的开拓研究主要还是弗农.史密斯开始的。他不仅自己在这个领域做出了重要的贡献,还带动了一批学者进行这项研究,开创了独立的研究学派。他的贡献主要集中于竞争性市场机制的实验、不同拍卖形式的检验以及实验经济学方法等。
  1.市场机制
  史密斯关于实验经济学最早的研究是受张伯仑启发。张伯仑认为其实验结果是对完全竞争市场标准新古典模型的歪曲,因此放弃了这种实验。史密斯认为,参与实验者面临的实验环境越接近真实市场,实验的结果就可能越好。这样,他在一个复式口头拍卖(double oral auction)实验中,把参与实验者随机分成两组:潜在的买者和卖者。给每个卖者一单位商品,并且秘密告诉他该商品的保留价格(reservation price)。假设保留价格为v,如果卖者卖出的价格p大于v,那么他就能够赚取p—v的报酬。同样,也秘密告诉每个买者一个w的保留价格,如果他购买商品的价格p小于w,那么他就可以得到w—p的报酬。基于这样一种保留价格分配,史密斯画出了供给和需求曲线,并在二者的交叉点确定了竞争均衡的价格。每个买者和卖者并不知道这一点,更不可能计算出理论上的均衡价格。但是,使他惊奇的是,他发现实际交易价格非常接近理论上的均衡价格。史密斯以后又进行了一系列类似实验以检验这一结果是否只是一种巧合。这些实验不但没有推翻最初的结果,反而使其得到进一步证实。在普洛特(Plott)和史密斯的合作研究中,他们不仅得出了同样的一般结论,而且还增加了一条:市场制度确实很“重要”。他们还特别比较了在交易达成过程中买卖双方可以连续不断交换价格信息情况下和双方只能邮寄价格情况下的结果。后一种情况的结果表明,实际交易价格只不过以比较慢的速度收敛于理论上的均衡价格。
  在几乎每一个市场实验中,对假设的检验都要求控制实验主体的偏好,但很困难。因为卖和买一般受买卖双方对收益和损失主观评价的影响,而这种主观评价是不可观测的。张伯仑首先提出了这个问题,并给出了一种解决办法,即给每个参与实验者提供一个“准确”的货币刺激。这种所谓的“诱导价格法(induced—value method)”经过史密斯的进一步发展,已经成为实验经济学的标准工具。
  为了阐明这种方法,考虑一个市场上购买同质商品的主体。假定实验者希望这个主体表达某种需求函数D,即在任何给定的价格下,该主体愿意购买的商品的准确数量q=D(p)。但是实验者不清楚该主体的效用函数u(W)。史密斯的方法是通过对参与实验者在价格p下的购买量q支付R(q)-pq的报酬归纳期望得到的需求函数,其中R是适当选择的报酬函数。根据经济理论,该主体选择的购买量q根据其从不断增加的q中得到的边际收益等于边际成本,即R’(q)=p确定。只要未知的效用函数递增且凹,其需求就会与期望得到的需求函数一致。因为在任何相应价格下,报酬函数R的反函数就恰好等于期望得到的需求函数,即任何相应价格p下,(R’)-1(p)=D(p)。该方法已经在实验经济学中得到广泛应用。
  2.对拍卖理论的检验
  拍卖理论作为微观经济理论和博弈论最成功的发展之一出现于20世纪60年代早期。史密斯对拍卖理论的假设进行了实验检验,他最先使用可控制实验作为新拍卖设计的“风洞”,因为这些设计在实际运用之前很难进行精确的理论预测。
  史密斯拍卖实验的研究集中于单一物体出售中运用某种拍卖形式的理论预测。这些拍卖传统上分为四种类型:
  英式拍卖:竞标者不断提高竞标价格,直到没有人再出更高价格为止,出价最高的竞标者获得该商品;
  荷式拍卖:出售者在确定的时间从某个高价开始逐渐向下降价,直到有人喊出“购买”为止;
  第一价格密封拍卖:众多买方以书面投标方式竞买拍卖品,出价最高者将以其出价水平获取拍卖品;
  第二价格密封拍卖:这一方式同第一价格密封拍卖类似,出价最高者获取商品,但其支付价格并非自身出价,而是所有出价者中仅次于该出价水平的第二出价。
  微观经济理论也区分了私人价值和共同价值拍卖。在两种情况下,对每个购买者来说价值是作为随机变量对待的。在私人价值下,这些估价在所有的潜在竞标者中相互独立——购买者的估价是其对物品的纯粹个人估价。相反,在共同价值拍卖中,对购买者来说价值也有共同成分,例如某些相关市场的再出售市场价值和条件。
  经济理论在私人价值情况下做了三个预测;(1)英式拍卖和第二价格密封拍卖等价;(2)荷式拍卖和第一价格密封拍卖等价;(3)如果所有购买者都是风险中性的,那么四种拍卖形式等价。
  史密斯做了许多实验以从经验上检验这些理论预测。为了出现私人价值,给每个竞标者指定一个随机的、相互独立的竞价v,这是每个竞标者的私人信息。如果竞标者赢得了拍卖并且支付了价格pt它就会赚p—v的货币收入。对于上面的预测(1),史密斯发现英式拍卖和第二价格密封拍卖确实产生了相同的实验结果;对于(2),与理论预测相反,荷式拍卖和第一价格密封拍卖并没有产生相同的结果;至于(3),他发现假定购买者具有相同风险态度的模型应被放弃。他还发现,英式拍卖和第一价格密封拍卖的平均价格要高于第二价格密封拍卖;后者的平均价格又高于荷式拍卖。
  在所有这些结果中,最没有预料到的结果就是荷式拍卖和第一价格密封拍卖不等价。史密斯给出了两个理论解释:(1)在荷式拍卖中,效用不仅仅依赖于货币结果,还依赖于“等待的不确定性”;(2)在荷式拍卖中,竞标者低估了与等待相关的不断增加的风险(Smith,1991)。
  3.作为“风洞”的实验室
  史密斯等人为了研究放松管制、私有化和公共物品供给制度机制的绩效,开始运用实验室作为“风洞”。这些机制非常复杂,现存的理论根本无法给出准确预测,这就使得实验方法特别有效。在一系列研究中,他研究了公共物品供给的激励相容机制设计。在这些实验中,史密斯检验了经济理论者提出的机制的有效性。史密斯还利用计算机对小型飞机时间通道的分配和能源市场的选择性组织进行了实验。
  4.实验经济学方法论
  史密斯除了对市场和拍卖结果的研究外,还在实验经济学的方法论方面做出了重要贡献。它的实验经济学方法论主要来自心理学中使用的实验方法。为了超过决定成本的歪曲效应,他强调给参与实验者足够货币刺激的重要性。它的方法还强调按照重复路径设计实验的重要性,以便于参与实验者熟悉和明白实验情景。但是其方法与心理学还有很多差别。心理学家主要是对个人行为感兴趣;史密斯设计实验主要是为了分析市场结果。
  史密斯的实验经济学研究方法不仅对经济学家产生了重要影响,而且还影响了其他社会科学。目前这一方法已经运用到多数裁定原则的委员会过程等政治领域。
  三、结语
  丹尼尔.卡尼曼运用回答问题、形成判断和做出选择思维过程的认知心理学研究,有助于我们更好地理解人们怎样做出经济决策。其他的心理学家在同样问题上也做出了重要贡献。但是卡尼曼和特韦尔斯基关于不确定条件下决策的研究更具影响。卡尼曼还对行为经济学的其他领域做出了重要贡献。目前,卡尼曼已经成为行为经济学和行为金融学领域最具影响的人物。其研究对其他学科也产生了重要影响,不仅在其他社会科学领域广泛运用,而且还在自然科学,例如人类学和医学中被广泛运用。
  弗农.史密斯是经验经济学研究最有影响的代表人物。与卡尼曼不同,他不是从对理性决策的传统经济理论提出挑战开始,而是从检验关于市场绩效的可选择性假定开始,特别研究了不同市场制度的重要性。卡尼曼的调查和实验主要集中于个体决策;而史密斯的实验集中于个体和特定市场环境的相互作用。史密斯也强调方法论问题,发展了可行的实验方法,并且建立了形成良好实验的标准。查理斯.普洛特进一步发展了史密斯的实验方法,并且开拓了对新领域的实验研究。通过史密斯取得的成就,许多经济学家认识到实验方法可以成为经济学的一个重要研究工具。
  新制度经济学家已经把认知科学作为其研究的一个领域(John Drobak and John Nye,1997)。1993年诺贝尔经济学奖获得者道格拉斯.诺思在20世纪90年代的时候对传统经济学的理性假说产生了怀疑,试图解释意识形态如何对人类行为发生作用(North,1997)。这说明认知科学、心理学与经济学研究的结合已经引起经济学家的高度关注。
  目前该领域研究的一个趋势是心理学传统和实验经济学的融合。这项新的研究对经济学和金融学的所有领域都非常重要。经验证据表明,特定的心理现象——例如有限理性、受限的自利行为和不完全自我控制——是一系列市场结果背后的重要因素。虽然行为经济学的理论还不是很多,但是通过其发展,最终有可能取代传统经济理论的一些要素。金融经济学要深入研究市场投机消除系统非理性对资产价格影响的程度。
  尽管卡尼曼和史密斯的研究在许多方面不同,但是他们的共同科学贡献已经对经济学的发展方向提出了挑战。过去经济学仅限于在相对简单的人类决策理性模型上理论化,还局限于对现实资料的经验研究。卡尼曼和史密斯的最初研究刚开始时,曾受到某些经济学家的怀疑,他们花费大量时间进行了更深入的研究,其理论已经完全渗透到经济学领域。由于他们取得的成就,许多或大多数经济学家开始把心理学研究和实验方法看作现代经济学的重要组成部分。
  
作者:李增刚 来源:《经济评论》2002第6期

2009年1月9日星期五

类馅饼----中央首次全国范围为困难群众发放生活补贴

中央首次全国范围为困难群众发放生活补贴
http://finance.QQ.com  2009年01月09日14:45   中国新闻网   我要评论(7820)
中新网北京1月9日电 (记者张希敏)中国民政部副部长姜力在今天召开的视频会上说,为妥善安排困难群众的基本生活,中央财政下拨九十多亿元人民币,为七千四百多万城乡困难群众发放一次性生活补贴。
姜力指出,民政部会同财政部对此次发放生活补贴的对象范围确定为全国城乡低保对象、农村五保对象、享受国家抚恤补助的的优抚对象等人。补贴标准为:农村低保对象和农村五保对象每人一百元,城市低保对象每人一百五十元,享受国家抚恤补助的优抚对象、建国前入党的农村老党员和建国前未享受离退休待遇的城镇老党员每人一百八十元。
民政部、财政部要求,各级民政部门和财政部门精心组织、全力以赴,确保春节前将补贴资金全部发放到位,并加强对资金的发放管理工作,做到资金发放公正、公平、透明,确保专款专用。

2009年1月8日星期四

FB jjgzz

散文《在哪里》忙碌的公仆在哪里?在包厢里。重要的工作在哪里?在宴会里。干部的任免在哪里?在交易里。工程的发包在哪里?在暗箱里。该抓的工作在哪里?在口号里。需办的急事在哪里?在会议里。该刹的歪风在哪里?在通知里。扶贫的干部在哪里?在轿车里。宝贵的人才在哪里?在悼词里。优质的商品在哪里?在广告里。破烂的危房在哪里?在农村里。豪华的大楼在哪里?在机关里。动听的词汇在哪里?在汇报里。辉煌的数字在哪里?在总结里。巨大的成绩在哪里?在水分里。可喜的进步在哪里?在创意里。