評(píng)論
打印
Forecasting the present
預(yù)測(cè)當(dāng)下
Taking the economic pulse
把握經(jīng)濟(jì)脈動(dòng)
How to gauge the current state of the economy
如何衡量當(dāng)前經(jīng)濟(jì)狀態(tài)
IT IS hard to predict the future: witness forecasters' failure to foresee the financial crisis. Indeed, even ascertaining the current state of the economy is tricky. The first official estimates of quarterly GDP are generally published between four and six weeks after each quarter has finished. Interpreting them can be fraught since they are frequently revised. Such delays and uncertainties have led economy-watchers to search for other gauges.
預(yù)測(cè)未來(lái)是困難的：你看看那些未能成功預(yù)見(jiàn)金融危機(jī)的預(yù)測(cè)機(jī)構(gòu)就知道了。事實(shí)上，即使要確定經(jīng)濟(jì)的當(dāng)前狀態(tài)也是棘手的。官方對(duì)季度GDP的估測(cè)一般是在每個(gè)季度結(jié)束后的4到6周方才公布。這些數(shù)據(jù)經(jīng)常修訂，要對(duì)它們做出解釋實(shí)在挑戰(zhàn)重重。而發(fā)布數(shù)據(jù)的拖延和不確定性也導(dǎo)致經(jīng)濟(jì)觀察家們轉(zhuǎn)而尋求其他的經(jīng)濟(jì)度量方式。
Simply asking business-folk what they think is a venerable tradition—Britain's Industrial Trends for example dates back to 1958—but such surveys are flourishing as never before. Among the most influential are purchasing-manager indices. Every month managers in both manufacturing and private services are asked whether their firms' output, employment, orders and the like have expanded or contracted. An index based on the net balance of their answers shows expansion above the level of 50 and contraction below it.
單刀直入問(wèn)問(wèn)商人們的想法是一個(gè)古老的傳統(tǒng)，這可以追溯到1958年時(shí)的英國(guó)產(chǎn)業(yè)動(dòng)態(tài)—但此類調(diào)查如今正經(jīng)歷前所未有的蓬勃發(fā)展。其中最有影響的是采購(gòu)經(jīng)理人指數(shù)。每個(gè)月，制造業(yè)和私人服務(wù)業(yè)的經(jīng)理們都會(huì)被問(wèn)到他們公司的產(chǎn)出，就業(yè)，訂單量之類是否擴(kuò)大或縮小。根據(jù)他們的答案得出一個(gè)凈差額指數(shù)，若指數(shù)高于50，則是經(jīng)濟(jì)擴(kuò)張的訊號(hào)，若低于50，則表明經(jīng)濟(jì)緊縮。
These findings can in turn be used to estimate the current rate of growth, given the previous relationship between the indices and GDP. For example, Markit, a research group, reported this week that their composite index for manufacturing and services in the euro zone stood at 52.8 in June. The survey suggests the euro area should grow by around 0.4% in the second quarter, twice as fast as in the first, says Chris Williamson, an economist at Markit.
基于這個(gè)指數(shù)以往與GDP之間的聯(lián)系，這些發(fā)現(xiàn)可以反過(guò)來(lái)用于估計(jì)目前的經(jīng)濟(jì)增長(zhǎng)速度。舉個(gè)例子，根據(jù)研究小組麥蓋提本周的報(bào)告，6月份歐元區(qū)制造業(yè)和服務(wù)業(yè)的綜合指數(shù)為52.8。麥蓋提的經(jīng)濟(jì)學(xué)家克里斯·威廉姆森說(shuō)，本項(xiàng)調(diào)查顯示，歐元區(qū)第二季度經(jīng)濟(jì)增長(zhǎng)率約為0.4%，是第一季度增速的兩倍。
Markit's estimate of second quarter euro-zone GDP growth appeared six weeks before the first official estimate. Such surveys have other benefits:the method is transparent and easy to grasp. And the findings are not revised once the final reports emerge a week after the “flash” estimates.
麥蓋提公布的有關(guān)第二季度歐元區(qū)GDP的增長(zhǎng)估測(cè)比官方評(píng)估結(jié)果整整早了六周。而且這樣的調(diào)查還有其他好處：使用的方法完全透明且易于掌握。而且，一旦“閃電”估測(cè)一周后產(chǎn)生了最終報(bào)告，估測(cè)結(jié)果將不再進(jìn)行修正。
Some data providers go further, seeking to exploit all relevant statistics, such as official figures for new passenger-car registrations. This requires a sophisticated model to extract a common signal for GDP from the welter of data that become available. This is the approach adopted by Now-Casting Economics, a firm whose founders include two economists, Lucrezia Reichlin and Domenico Giannone. In the case of the euro zone, their model gobbles up 50 monthly variables and uses their past relationships with GDP to calculate an estimate for the current quarter. At present the firm, whose clients are hedge funds and other asset managers, is expecting growth of 0.26% in the second quarter—somewhat more sluggish than Markit's estimate.
有些數(shù)據(jù)供應(yīng)商則走的更遠(yuǎn)，尋求利用所有相關(guān)的統(tǒng)計(jì)信息，比如有關(guān)新型乘用車注冊(cè)的官方數(shù)字。這需要一個(gè)復(fù)雜的模型來(lái)從冗雜的數(shù)據(jù)中提取出有關(guān)GDP的通用信號(hào)。目前，短時(shí)預(yù)測(cè)經(jīng)濟(jì)公司正是采用這種方法，其創(chuàng)始人包括兩位經(jīng)濟(jì)學(xué)家，盧克雷西婭·賴希林和多梅尼科·詹諾內(nèi)。在歐元區(qū)范圍內(nèi)，他們使用模型抓取了50個(gè)月的變量，并利用其過(guò)去與GDP的聯(lián)系來(lái)計(jì)算、估測(cè)本季度的經(jīng)濟(jì)形式。該公司的客戶是對(duì)沖基金和其他資產(chǎn)管理公司，目前它預(yù)期二季度經(jīng)濟(jì)增長(zhǎng)率為0.26%，略低于麥蓋提公布的估測(cè)數(shù)據(jù)。
In principle, the model-based approach might appear superior because it exploits more information. On the other hand, it is more of a black box. Since surveys are themselves an important source of information for the nowcasts this suggests that the two methods will co-exist.
原則上而言，因?yàn)榛谀Ｐ偷慕y(tǒng)計(jì)方式利用到更多的信息，可能會(huì)比普通方法更勝一籌。然而另一方面，它更多的是一個(gè)黑盒測(cè)試。由于調(diào)查本身也是短時(shí)預(yù)測(cè)信息的重要來(lái)源，這兩種調(diào)查方式將會(huì)共存。
