别妄想跳下财政悬崖

As the deficit reduction debate drags on, talk is growing in Washington about allowing the US to go over the fiscal cliff, triggering $600bn of spending cuts and tax increases in the new year. Some are suggesting that doing so would not be too damaging to the economy. Or even that it would be a good tactical move, providing the new Congress with an incentive to reach a significant budget accord.

就在各界继续就减赤方案展开辩论之际，有关听由美国跌落财政悬崖的言论在华盛顿逐渐升温，这意味着新一年的减支和增税规模将达到6000亿美元。有人认为，听由美国跌落财政悬崖不会对经济造成太具破坏性的影响。他们甚至认为，听由美国跌落财政悬崖是一种颇具策略的做法，将令新一届美国国会有动力去达成重大预算协议。

Such thinking seriously underestimates the cost of going over the cliff. The willingness to contemplate failure is perhaps understandable. The Congressional Budget Office has estimated that while the economy would shrink at an annualised rate of 1.3 per cent during the first half of next year were the cliff not averted, growth would rebound to 2.3 per cent in the second half of 2013.

这种看法严重低估了跌落财政悬崖可能带来的成本。各界有兴趣考量跌落财政悬崖的潜在后果，这或许可以理解。美国国会预算办公室(Congressional Budget Office)的测算结果显示，如果未能避开财政悬崖，来年上半年美国经济的年化增长率将为负1.3%，但2013年下半年经济增速将反弹至2.3%。

But the CBO estimates are far too conservative. The fiscal drag implied by going over the cliff would subtract about $1tn (6.3 per cent of gross domestic product) from projected growth over the 18 months from January 2013. Given the consensus forecast for 2 per cent growth next year, that leaves a growth rate of -2.2 per cent for 2013. This calculation is consistent with estimates reported in October by the IMF.

但国会预算办公室的测算结果过于保守。美国跌落财政悬崖带来的财政支出下降，将在始于2013年1月的18个月里导致美国经济预期增长量减少约1万亿美元（约占这段时期美国国内生产总值(GDP)的6.3%）。鉴于各界普遍预计下一年的美国经济增长率为2%，美国跌落财政悬崖将导致2013年美国经济出现2.2%的负增长。该结果与国际货币基金组织(IMF)今年10月发表的预测结果一致。

An extant American liquidity trap explains why the recession would be so severe. Such a trap exists when interest rates are frozen at zero and cannot fall. It magnifies the negative impacts of austerity. Absent the trap, the drag on GDP from tighter fiscal policy is usually mitigated by falling interest rates. Interest rates tend to fall, as household and business incomes drop and demand for money and credit shrinks. Lower interest rates then boost private sector spending, partially offsetting the fiscal drag from higher taxes and government spending cuts.

美国目前处于流动性陷阱，这就是为何财政紧缩将导致如此严重经济衰退的原因。当利率水平降至零点、以至于没有进一步下跌的空间时，流动性陷阱就产生了。流动性陷阱将放大财政紧缩政策对经济的负面影响。如果没有流动性陷阱，财政紧缩政策导致的国内生产总值减少通常能被利率下跌所淡化。而利率倾向于会下跌则是因为，家庭和企业收入下降，货币需求和信贷需求也出现萎缩。较低的利率水平然后会提振私人部门的支出，部分抵消增税以及政府减支带来的财政拖累(fiscal drag)。

But in a liquidity trap, with interest rates stuck at zero, there is no offset to the fiscal drag. In technical terms, the negative multiplier is larger than usual. The IMF has produced evidence that negative fiscal multipliers have indeed been larger than expected since the start of the financial crisis, which has coincided with interest rates falling close to zero and economies stuck in liquidity traps.

但在陷入流动性陷阱的情况下，由于利率水平已固定在零点、无法进一步降低，财政拖累无法得到抵消。用专业术语表达，这种情况下的负乘数效应高于通常水平。国际货币基金组织举出的证据显示，财政负乘数效应自金融危机爆发以来确实一直超出预期，这恰好与利率降至零点附近以及经济陷入流动性陷阱发生在同一时间。

The enhanced fiscal drag tied to austerity programmes such as those in Greece, Portugal and Spain must have come as a nasty shock. During 2010 and 2011 some European central bankers were arguing that the boost to confidence from cutting deficits would mean that austerity might actually stimulate those economies. It did not. Instead, in the absence of interest rate reductions, the drop in incomes engendered by austerity so depressed tax receipts that the ratio of government debt-to-GDP has increased in southern Europe.

与类似希腊、葡萄牙和西班牙等国的紧缩方案相联系的财政拖累(fiscal drag)提高，肯定造成了非常严重的冲击。在2010年和2011年期间，一些欧洲国家的央行官员辩称，减赤对信心的提振可能意味着，紧缩可能在事实上对上述几个经济体产生刺激效果。事实上并非如此。相反，由于没有配合降息，紧缩造成的收入下降导致税收受到影响，南欧国家政府债务对国内生产总值(GDP)的比例事实上升高了。

Three lessons emerge from the larger negative fiscal multiplier implied by America’s liquidity trap and from Europe’s sad experience with austerity. First, do not even think about going over the fiscal cliff. Even a “half cliff – fiscal drag of 2.1 per cent of GDP – would put the US economy in a recession for all of 2013. Second, don’t expect the Federal Reserve to offset fiscal drag. It can’t. Conventional monetary policy cannot stimulate spending, because the Fed cannot lower interest rates. Nor can quantitative easing because it is being undercut by a growing demand for liquidity as businesses and households confront uncertainty, ranging from fiscal cliff negotiations to healthcare revisions and a possible collapse of the euro.

美国遭遇流动性陷阱、导致财政负乘数效应增大，以及欧洲对紧缩政策的痛苦体验，向世人提供了三条教训。第一，对于听由美国跌下财政悬崖这件事，甚至想都不要想。即便是跌落一半(half cliff)——指占GDP2.1%的财政拖累——也足以令美国经济在2013年全年陷入衰退。第二，不要指望美联储(Fed)能消除财政拖累的负面效果。美联储无计可施。通常的货币政策手段无法刺激支出，因为美联储已经没有降息空间了。量化宽松也将不起作用，这是因为，面对从财政悬崖谈判、医保制度改革、到欧元崩溃的可能性等诸多不确定性，企业和家庭对流动性的需求日益上升，这将削弱量化宽松的作用。

The third lesson applies to the design of fiscal tightening. If averting the fiscal cliff requires a Republican concession on tax rates for “the rich in exchange for entitlement reforms, the rise in such rates should be minimised – to 2 percentage points at most – by simultaneously reducing regressive tax allowances. Taxpayers with incomes of more than $250,000 will already start paying an extra 3.8 per cent Medicare tax on all income from January 1 2013.

第三个教训是在财政紧缩举措的设计方面。如果避免财政悬崖需要共和党做出让步、同意对“富人增税，以换取民主党在福利改革方面做出让步，那么增税幅度也应控制在最低——最多不超过两个百分点——同时调低累退税的额度。从2013年1月1日起，年收入超过25万美元的纳税人就将开始额外上缴3.8%的联邦医疗保险税(Medicare tax)了。

Then during 2013, Congress should specify a decade-long programme to stabilise and then reduce the debt-to-GDP ratio, without hurting growth. That programme should include entitlement reform and fund phased reductions of marginal tax rates by further reducing allowances. Once such a programme is passed, talk of “unsustainable deficits should cease, confidence rise, and the US move back to stable, non-inflationary growth of 3 to 3.5 per cent.

2013年内，美国国会应当拿出一份具体的十年方案，以便在不损害增长的情况下，稳定、进而降低政府债务对GDP的比例。该计划中应当包含福利改革，也应通过进一步调低累退税额度弥补边际税率的分段调低造成的收入减少。一旦这样一个方案获得通过，赤字“不可持续论应该就会销声匿迹，信心就会回升，然后美国经济将重新企稳，实现3%至3.5%的无通胀增长。

The writer is a resident scholar at the American Enterprise Institute

本文作者为美国企业研究所(American Enterprise Institute)驻院学者