【英语财经】英国经济的生产率难题 The age of a most important uncertainty is upon us

Productivity is not everything, but in the long run it is almost everything. This truth, enunciated by the Nobel laureate Paul Krugman, has just bitten George Osborne, the UK chancellor. But the prospects for productivity are not important just to Mr Osborne. They are the most important uncertainty affecting the economic prospects of the British people. Is it reasonable to expect a return to buoyant pre-crisis productivity growth? Will productivity continue to stagnate? Or will it end up somewhere in between?

The negative impact on the budgetary position of the Office for Budget Responsibility’s mild revisions to productivity projections shows how much this matters. The reduction in the OBR’s forecast rate of growth in output per hour — a basic measure of productivity — is only by an average of 0.2 percentage points a year. Yet, notes the OBR, “cumulated over five years, that represents a material downward revision to the level of potential output by 2020”.

In its latest forecast, the OBR expects UK productivity levels to be 6.2 per cent lower in 2020 than it had hoped in June 2010 and 2.5 per cent lower than it had hoped in March 2014. But the biggest downgrades of all are relative to the pre-crisis optimism: the OBR’s latest forecast for potential output in 2020 is 15 per cent below the Treasury’s March 2008 forecast. Similar downgrades have occurred to the official US forecasts.

Yet even the new forecasts might be too optimistic. The question is whether the post-crisis productivity stagnation or the pre-crisis productivity growth will be the next normal. The OBR still largely assumes the latter. Thus, the 1971-2007 average growth of productivity was 2.2 per cent a year. The 2008-2015 average has been a mere 0.3 per cent. The latest forecast is that productivity growth will rise from 0.8 per cent last year to 2 per cent by 2019. That would be close to to pre-crisis norms.

Assume, instead, that productivity growth will be 1 per cent this year and stays there. Potential output in 2020 would be 4 per cent lower than the OBR now assumes. That would leave the chancellor not with his planned surplus, but a big fiscal deficit. Thereafter, the gap between output with productivity growth at 2 per cent and output with productivity growth at 1 pe r cent would rise further: by 2030, potential output would be 13 per cent lower than a continuation of the OBR’s latest productivity growth assumption would imply.

Evidently, we need to understand why productivity growth has been so weak. The OBR concludes that productivity growth has been lower in most industries since 2008, with the most pronounced falls in financial services and supply of gas and electricity. On balance, then, the decline in productivity growth has been across the board.

One explanation might be the impact of the financial crisis on credit. But, as the financial sector heals, this is less persuasive. Another explanation must be the post-crisis collapse in business investment, to a low of 8.1 per cent of gross domestic product, in real terms, in the fourth quarter of 2009. But this has since recovered. It would be good if business investment were still higher. But it is hard to believe that low investment continues to explain the persistent productivity disappointments. Again, GDP might be mismeasured. But it is difficult to understand why such mismeasurement suddenly jumped after 2008. Maybe growth of GDP and productivity is higher than measured. But that should also have been true before 2008.

Given the huge uncertainty, the OBR has made only a modest step in the direction of assuming the reduction in productivity growth is permanent. It could easily still be far too optimistic.

So how should policymakers respond to these unpleasant uncertainties?

The first shift should be towards policies likely to raise productivity growth. An essential element in such a shift must be towards higher public and private investment. The government should invest more. It should also be looking at changes in the system of taxation that would encourage investment.

The second shift must be towards asking how to manage the public finances if the economy does not return to pre-crisis productivity trends. That would evidently require still tighter control over current spending. But it is also likely to require raising taxes that do not distort the economy. The obvious candidates are higher taxation of public bads (congestion and pollution) and heavier taxation of rents, particularly of land.

We must hope that the Treasury is devoting serious thought to these unpleasant contingencies. The OBR’s latest downward revision might prove to be a small step towards reality. Things could, alas, be worse. So prepare now.

生产率不是一切，但长期而言，它几乎意味着一切。诺贝尔奖(Nobel)得主保罗?克鲁格曼(Paul Krugman)阐明的这个真理，刺痛了英国财政大臣乔治?奥斯本(George Osborne)。但生产率的前景不仅仅对奥斯本重要。它也是影响英国民众经济前景的最重要不确定性。我们是否有理由指望生产率增速会回到危机前的强劲水平？生产率是否会继续停滞？或者是否会最终停留在介于二者之间的某个水平？

英国预算责任办公室（Office for Budget Responsibility，简称OBR）对生产率预期的微调对预算状况的负面影响表明，它事关重大。OBR对预期每小时产出（衡量生产率的基本标准）增速的下调幅度平均仅为每年0.2个百分点。然而，OBR指出，“经过5年的累积，这代表着到2020年潜在产出水平将出现重大下调”。

OBR在最新预测中预计，到2020年，英国生产率水平将比2010年6月的预测低出6.2%，比2014年3月的预测低出2.5%。但其中幅度最大的下调是相对于危机前的乐观主义的：OBR对2020年潜在产出的最新预测，较英国财政部2008年3月的预测低出15%。类似的下调也出现在美国官方预测中。

然而，甚至连这一最新预测也可能过于乐观了。问题在于，下一个常态会是危机后的生产率停滞还是危机前的生产率增长。OBR仍基本上认为会是后者。因此，1971年至2007年生产率的平均增速是每年2.2%。2008年至2015年的平均增速只有0.3%。最新预测是，生产率增速将从去年的0.8%升至2019年的2%。这将接近危机前的正常水平。

假设生产率增速今年达到1%并维持在这一水平，那么2020年的潜在产出将比OBR现在的预测低出4%。这将让奥斯本面临巨额财政赤字，而非计划中的财政盈余。之后，生产率增速为2%时的产出与生产率增速为1%时的产出之间的差距将进一步拉大：到2030年，潜在产出将比一直按照OBR最新生产率增速预测得出的最后值低出13%。

显然，我们需要弄明白生产率增速为何如此疲弱。OBR总结称，自2008年以来，多数行业的生产率增速下滑，下滑最为显著的是金融服务业以及天然气和电力供应业。因此，总的来说，生产率增速下滑是全方位的。

一种解释可能是此次金融危机对信贷的影响。但随着金融业的复原，这一点的说服力不那么强了。另一种解释肯定是危机后实际企业投资的大幅滑坡，2009年第四季度降至占国内生产总值(GDP)8.1%的低位。但此后形势有所好转。如果企业投资再高一些会很好。但很难相信投资低下将继续解释生产率的长期令人失望。此外，GDP可能被错误衡量。但很难理解为什么这种错误衡量会在2008年后突然出现。或许GDP和生产率增速高于衡量结果。但在2008年以前也应该如此。

鉴于巨大的不确定性，在假设生产率增速下滑将是永久性的方面，OBR仅迈出了一小步。它很可能仍然过于乐观。

那么，政策制定者应对这些不受人欢迎的不确定性做何回应？

第一个调整应是采取可能会提高生产率增速的政策。这种调整的重要部分肯定是提高公共部门和私营部门投资。英国政府应扩大投资。政府还应考虑对税制做出能够促进投资的修改。

第二个调整肯定是研究这样一个问题：如果经济没有回归危机前的生产率趋势值，要如何管理公共财政。这显然需要对当前的支出进行更加严格的控制。但这也可能需要在不扭曲经济的情况下提高税收。明显的可行方案是提高对公害（拥堵和污染）和租金（尤其是土地租金）的税收。

我们肯定希望英国财政部正对这些不受欢迎的意外事件进行严肃思考。OBR最新的下调预期之举事实上可能是朝着现实迈出的一小步。唉，情况可能会更糟。那么现在就做好准备吧。

译者/梁艳裳