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格老鸣冤:美联储不是住房泡沫祸首

发布者: chrislau2001 | 发布时间: 2009-3-12 14:39| 查看数: 1245| 评论数: 1|

Greenspan:Fed Didn't Cause The Housing Bubble







Alan Greenspan

We are in the midst of a global crisis that will unquestionably rank as the most virulent since the 1930s. It will eventually subside and pass into history. But how the interacting and reinforcing causes and effects of this severe contraction are interpreted will shape the reconfiguration of our currently disabled global financial system.

There are at least two broad and competing explanations of the origins of this crisis. The first is that the 'easy money' policies of the Federal Reserve produced the U.S. housing bubble that is at the core of today's financial mess.

The second, and far more credible, explanation agrees that it was indeed lower interest rates that spawned the speculative euphoria. However, the interest rate that mattered was not the federal-funds rate, but the rate on long-term, fixed-rate mortgages. Between 2002 and 2005, home mortgage rates led U.S. home price change by 11 months. This correlation between home prices and mortgage rates was highly significant, and a far better indicator of rising home prices than the fed-funds rate.

This should not come as a surprise. After all, the prices of long-lived assets have always been determined by discounting the flow of income (or imputed services) by interest rates of the same maturities as the life of the asset. No one, to my knowledge, employs overnight interest rates -- such as the fed-funds rate -- to determine the capitalization rate of real estate, whether it be an office building or a single-family residence.

The Federal Reserve became acutely aware of the disconnect between monetary policy and mortgage rates when the latter failed to respond as expected to the Fed tightening in mid-2004. Moreover, the data show that home mortgage rates had become gradually decoupled from monetary policy even earlier -- in the wake of the emergence, beginning around the turn of this century, of a well arbitraged global market for long-term debt instruments.

U.S. mortgage rates' linkage to short-term U.S. rates had been close for decades. Between 1971 and 2002, the fed-funds rate and the mortgage rate moved in lockstep. The correlation between them was a tight 0.85. Between 2002 and 2005, however, the correlation diminished to insignificance.

As I noted on this page in December 2007, the presumptive cause of the world-wide decline in long-term rates was the tectonic shift in the early 1990s by much of the developing world from heavy emphasis on central planning to increasingly dynamic, export-led market competition. The result was a surge in growth in China and a large number of other emerging market economies that led to an excess of global intended savings relative to intended capital investment. That ex ante excess of savings propelled global long-term interest rates progressively lower between early 2000 and 2005.

That decline in long-term interest rates across a wide spectrum of countries statistically explains, and is the most likely major cause of, real-estate capitalization rates that declined and converged across the globe, resulting in the global housing price bubble. (The U.S. price bubble was at, or below, the median according to the International Monetary Fund.) By 2006, long-term interest rates and the home mortgage rates driven by them, for all developed and the main developing economies, had declined to single digits -- I believe for the first time ever. I would have thought that the weight of such evidence would lead to wide support for this as a global explanation of the current crisis.

However, starting in mid-2007, history began to be rewritten, in large part by my good friend and former colleague, Stanford University Professor John Taylor, with whom I have rarely disagreed. Yet writing in these pages last month, Mr. Taylor unequivocally claimed that had the Federal Reserve from 2003-2005 kept short-term interest rates at the levels implied by his 'Taylor Rule,' 'it would have prevented this housing boom and bust.'This notion has been cited and repeated so often that it has taken on the aura of conventional wisdom.

Aside from the inappropriate use of short-term rates to explain the value of long-term assets, his statistical indictment of Federal Reserve policy in the period 2003-2005 fails to address the aforementioned extraordinary structural developments in the global economy. His statistical analysis carries empirical relationships of earlier decades into the most recent period where they no longer apply.

Moreover, while I believe the 'Taylor Rule' is a useful first approximation to the path of monetary policy, its parameters and predictions derive from model structures that have been consistently unable to anticipate the onset of recessions or financial crises. Counterfactuals from such flawed structures cannot form the sole basis for successful policy analysis or advice, with or without the benefit of hindsight.

Given the decoupling of monetary policy from long-term mortgage rates, accelerating the path of monetary tightening that the Fed pursued in 2004-2005 could not have 'prevented' the housing bubble. All things considered, I personally prefer Milton Friedman's performance appraisal of the Federal Reserve. In evaluating the period of 1987 to 2005, he wrote on this page in early 2006: 'There is no other period of comparable length in which the Federal Reserve System has performed so well. It is more than a difference of degree; it approaches a difference of kind.'

How much does it matter whether the bubble was caused by inappropriate monetary policy, over which policy makers have control, or broader global forces over which their control is limited? A great deal.

If it is monetary policy that is at fault, then that can be corrected in the future, at least in principle. If, however, we are dealing with global forces beyond the control of domestic monetary policy makers, as I strongly suspect is the case, then we are facing a broader issue.

Global market competition and integration in goods, services and finance have brought unprecedented gains in material well being. But the growth path of highly competitive markets is cyclical. And on rare occasions it can break down, with consequences such as those we are currently experiencing. It is now very clear that the levels of complexity to which market practitioners at the height of their euphoria tried to push risk-management techniques and products were too much for even the most sophisticated market players to handle properly and prudently.

However, the appropriate policy response is not to bridle financial intermediation with heavy regulation. That would stifle important advances in finance that enhance standards of living. Remember, prior to the crisis, the U.S. economy exhibited an impressive degree of productivity advance. To achieve that with a modest level of combined domestic and borrowed foreign savings (our current account deficit) was a measure of our financial system's precrisis success. The solutions for the financial-market failures revealed by the crisis are higher capital requirements and a wider prosecution of fraud -- not increased micromanagement by government entities.

Any new regulations should improve the ability of financial institutions to effectively direct a nation's savings into the most productive capital investments. Much regulation fails that test, and is often costly and counterproductive. Adequate capital and collateral requirements can address the weaknesses that the crisis has unearthed. Such requirements will not be overly intrusive, and thus will not interfere unduly in private-sector business decisions.

If we are to retain a dynamic world economy capable of producing prosperity and future sustainable growth, we cannot rely on governments to intermediate saving and investment flows. Our challenge in the months ahead will be to install a regulatory regime that will ensure responsible risk management on the part of financial institutions, while encouraging them to continue taking the risks necessary and inherent in any successful market economy.

最新评论

chrislau2001 发表于 2009-3-12 14:52:27


们身处的这场全球危机毫无疑问是上世纪三十年代以来最为严峻的。危机终将平息,成为历史一页。在这段严重收缩时期中,因和果相互影响,相互强化。如何对它们进行解读,这个问题关系到如何对当前失效的全球金融体系进行重组。

对于这场危机的根源至少有两种影响广泛的不同解释。第一种解释是,美国联邦储备委员会(Federal Reserve,简称:美联储)的宽松货币政策导致了美国房产泡沫,而这正是当前金融混乱的核心所在。

第二种更为可信的解释认同较低的利率导致投机热的说法,不过,起重大作用的利率并非联邦基金利率,而是长期固定利率抵押贷款的利率水平。2002-2005年,住房抵押贷款利率的变化领先美国房价变化11个月。房价与抵押贷款利率之间的这种关联度意义重大,是比联邦基金利率更能预示房价上涨的一个指标。

这应当不会出乎意料。毕竟,长期资产的价格一直是用与其具有相同期限资产的利率,对将来的收入流(或应计服务收入)进行贴现来决定的。就我所知,没有人会用联邦基金利率等隔夜拆息来确定房地产的资本化折算率,无论是写字楼还是单户住宅。



Chad Crowe



2004年中的时候,抵押贷款利率并没有如预期般对美联储的紧缩举措作出反应,美联储敏锐地意识到了货币政策和抵押贷款利率之间的脱节。而且,数据显示,住房抵押贷款利率甚至更早之前就开始逐渐与货币政策脱钩了──从世纪之交开始,一个套利活跃的全球性长期债务市场开始形成,此后脱钩的趋势就逐渐显现。

数十年来,美国抵押贷款利率和短期美国利率之间一直保持着密切联系。在1971年至2002年这段时间,联邦基金利率和抵押贷款利率亦步亦趋,双方的关联度为0.85,相当紧密。但在2002年至2005年,这种关联度下降到了无意义的程度。

正如2007年12月我在这里撰文所指出的,长期利率全球性下滑的假定原因是上世纪九十年代初全球经济的结构性转变,当时很多发展中国家从高度集中的计划经济转向了日益高效的、出口引导的市场竞争。这个变化的结果就是,中国和大量其他新兴市场经济体实现了高速增长,进而导致了全球计划储蓄相对计划资本投资的过剩。这一有意识的储蓄过剩推动全球长期利率在2000年初至2005年间日益显著地下滑。

各个国家长期利率水平普遍下滑,这从统计学上解释了全球房地产资本化折算率普遍下滑并逐步趋同,从而导致全球住房价格泡沫的现象,而且这可能也是造成这种现象的最主要原因。(美国价格泡沫当时处于或低于国际货币基金组织的统计中值。)到2006年的时候,在所有发达国家和主要发展中国家,长期利率及其带动的住房抵押贷款利率都降到了10%以下──我相信这是头一回。我本来以为,此类证据的重要性可能会使外界广泛支持这是当前危机的全球性原因。

不过,从2007年中开始,历史开始重写,这主要归功于我的好友兼前同事、斯坦福大学教授泰勒(John Taylor),我很少与他意见相左。上月在《华尔街日报》撰文时,泰勒毫不含糊地声称,如果美联储能够在2003年至2005年将短期利率保持在他的“泰勒定律”暗示的水平,那么这次住房市场的兴衰轮回本来是可以避免的。这个说法已经如此广为流传,以致于都披上了“传统智慧”的光环。

且不说用短期利率来解释长期资产价值是不合适的,泰勒对2003-2005年间美联储的政策进行了统计分析,并提出指责,但他的做法没有考虑到上文中提到的全球经济中非凡的结构性变化。他的统计分析把过去几十年中的经验性关系用到了现在,而眼下这类关系已经不再适用了。

此外,尽管我认为“泰勒定律”是对于货币政策路径的有益的初步近似,它的参数和预测却得自于始终无法预测衰退和金融危机的模型结构。从这样有缺陷的模型结构中得到的结论有悖于事实,不能仅仅以此作为成功的政策分析或建议的基础,无论它在事后是否有借鉴意义。

鉴于货币政策与长期抵押贷款利率的脱钩,加快美联储2004-2005年就在寻求的紧缩货币政策的步伐,也不会“防止”房市泡沫的产生。总的看来,我本人更喜欢弗里德曼(Milton Friedman)对美联储表现的评价。2006年初他在《华尔街日报》上撰文,对1987-2005年的那段时期进行了评估;他写道,在所有其他持续时间类似的时期里,美联储体系都没有像这个时期表现得那么好。它们之间的差别不只是程度上的,而且是接近于性质上的。

房市泡沫是由不当的货币政策(在这一点上政策制定者有控制权)造成的,还是由更广泛的全球力量(在这一点上他们能施加的控制有限)造成的?这一点有多重要?答案是:非常重要。

如果是货币政策的错,那么这个错误今后可以改正过来,至少理论上是这样。然而,如果我们正在应对的全球力量超出了国内货币政策制定者的控制(我强烈怀疑就是这样),那么我们面对的就是一个更广泛的问题。

全球市场竞争以及商品、服务和金融的整合,在物质上带来了前所未有的收获。不过,竞争激烈的市场的增长之路是周期性的。在罕见的情况下,它可能会瓦解,造成的后果就象我们现在经历的一样。现在已经非常清楚,处于亢奋状态的市场参与者试图将风险管理技术和产品推到如此高的复杂程度,就算是最老道的参与者都很难以适当、审慎的方式加以处理。

不过,适宜的政策反应并不是用大量的监管来限制金融中介活动。这样做会遏制能提高生活水平的金融业的重要进步。记住,在危机爆发之前,美国经济显示出了相当程度的生产力进步。在金融危机袭来之前,通过国内储蓄和借来的外国储蓄(我们的经常项目赤字)的适度结合来实现这一点,曾是衡量我们金融体系成功的尺度。此次危机揭示出解决金融市场问题的一个办法,就是更高的资本金要求和更普遍地惩罚欺诈行为,而不是政府机构加强微观管理。

任何新的规定都应该增强金融机构的能力,让它们更有效地把一个国家的储蓄引导到最具生产力的资本投资领域。大部分监管没有通过这项测试,而且常常代价不菲,适得其反。充足的资本和抵押品要求能解决危机暴露出来的弱点。这样的要求干预性不会过高,所以不会过度介入私人部门业务的决策。

如果我们要保持一个有能力实现繁荣和未来可持续增长的充满活力的世界经济,我们就不能依靠政府来调节储蓄和投资流向。未来几个月我们面临的挑战将是制定一个监管制度,确保金融机构对风险管理负起责任,同时还要鼓励它们继续承担任何成功的市场经济所固有的、必要的风险。
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