随着欧元危机的缓解，高油价成了世界经济的新忧虑之源。“石油就是新的希腊”这一代表性的题目出现在了汇丰的分析员最近的一份报告中。恐慌是可以理解的，伊朗局势很紧张，原有市场命悬一线。三月一号，伊朗媒体报道了爆炸摧毁了沙特阿拉伯一条重要的输油管道后，布伦特原油价格窜升到了128美元，每桶涨了5美元多，之后沙特否认了该说法，油价又跌到了125美元，不过这仍比年初贵16%。

　　Assessing the dangers posed by dearer oil means answering four questions: What is driving up the oil price? How high could it go? What is the likely economic impact of rises so far? And what damage could plausible future increases do?

　　评估油老大的风险敞口意味着回答四个问题：什么推高了油价？它能涨多高？目前可能的经济影响有什么？还有未来不确定的增长会造成什么危害？

　　The origins of higher prices matter. Supply shocks, for instance, do more damage to global growth than higher prices that are the consequence of stronger demand. One frequent explanation of the current rise is that central-bank largesse has sent oil prices higher. In recent months the world’s big central banks have all either injected liquidity, expanded quantitative easing (printing money to buy bonds) or promised to keep rates low for longer. This flood of cheap money, so the argument goes, has sent investors into hard assets, especially oil. But since markets are forward-looking, the announcement rather than the enactment of QE should move oil prices; indeed, the chairman of the Federal Reserve, Ben Bernanke, disappointed markets last month by not signalling another round of QE (see Buttonwood). Moreover, if rising prices are being driven by speculators you should see a rise in oil inventories—exactly the opposite of what has happened.

　　高油价的源头至关重要。比如，像供应异动对全球经济造成的危害就比需求走强型油价攀升大。对于目前的上涨，一个常被用到的解释就是央行的慷慨救助推升了油价。在近几个月里，全球各大央行不是在注入流动性，增加量化宽松（印钱买国债），就是在保证延长保持低利率的期限。就像争论的那样，廉价资金（不只是低息贷款，还有货币的贬值等）的涌入早把投资者推到了硬资产那边，特别是石油那里。不过因为市场是有预测性的，所以是量化宽松的宣布提升了油价，而不是实施。确实，上个月美联储主席本伯南克宣布没有下一轮量化宽松，是让市场很失望的。另外，如果价格上涨是由投机者造成的，你将会看到原油库存的增加——这完全与事实背道而驰。

　　Central banks may have affected oil indirectly, by raising global growth prospects, which in turn buoy expectations for oil demand. Circumstantial evidence supports this thesis. The recent rise in oil prices has coincided with greater optimism about the world economy: a euro-zone catastrophe and a hard landing in China both appear less likely and America’s recovery seems on stronger ground.

　　各大央行可能会通过提升全球增长预期来直接影响油价，而预期增长也会反过来支撑原油需求的预期。有详细的证据支持该论点。最近的油价上升是伴随着对全球经济过分乐观的：欧元区的大灾变和中国经济的硬着陆的都不太可能了，而且美国的复苏看起来也在稳步增强。

　　But slightly rosier growth prospects are only part of the story. A more important driver of dearer oil has been disruptions in supply. All told, the oil market has probably lost more than 1m barrels a day (b/d) of supply in recent months. A variety of non-Iranian troubles, from a pipeline dispute with South Sudan to mechanical problems in the North Sea, have knocked some 700,000 b/d off supply. Another 500,000 b/d or so of Iranian oil is temporarily off the market thanks both to the effects of European sanctions and a payment dispute with China.

　　不过，些许的美好增长前景只是故事的一部分。油老大更为重要的驱动力在于供应缺损。在近几个月里，原油市场每天可能总共损失一百万桶。从与南苏丹的管道纠纷到北海的机械故障，各种各样的非伊朗性问题每天就能搞砸70万桶供应。其余的每天50多万桶伊朗原油就因为欧盟的处罚和与中国的支付纠纷，暂时的离开了市场。

　　The cushion of spare supply is thin. Oil stocks in rich countries are at a five-year low. The extent of OPEC’s spare capacity is uncertain. Saudi Arabia is pumping some 10m b/d, a near-record high (see chart 1). And there is the threat of far bigger supply disruptions if Iran were ever to carry out its threat to close the Strait of Hormuz, through which 17m barrels of oil pass every day, some 20% of global supply. Even a temporary closure would imply a disruption to dwarf any previous oil shock. The 1973 Arab oil embargo, for instance, involved less than 5m b/d.

　　零散供给的缓冲作用挺弱的。石油类股票价格在发达国家创五年内新低，石油输出国组织OPEC的备用生产能力也不确定，沙特阿拉伯现在每天都抽1千万桶，也创了近期新高（见图一）。如果伊朗要封锁霍尔木兹海峡进行报复，这就是对供给损毁相当大的威胁，每天有一千七百万原油通过霍尔木兹海峡，占全球供给的２０％多。即使是短暂封锁造成的供应缩减也会使以前的石油危机相形见绌，例如，１９７３年阿拉伯的原油禁运每天才不到５百万桶。

　　Separating out these various factors is not easy, but Jeffrey Currie of Goldman Sachs reckons that the fundamentals of supply and demand have pushed oil prices to around $118 a barrel. He thinks the remaining increase is down to fears about Iran. If so, should relations with Iran improve, the oil price might go down by a few dollars, but stay close to $120.

　　区分这些种类繁多的因素是不容易的，但高盛的杰佛里库瑞Jeffrey Currie猜测，供求的基本面就把油价推升到了每桶１１８美元。他认为剩下的那些涨幅归根于对于伊朗的恐惧。如果这样，就应该改善与伊朗的关系，油价就能下降几美元，但也在１２０美元左右。

　　Globally, the damage from price increases to date is likely to be modest. A rule of thumb is that a sustained 10% rise in the price of oil shaves around 0.2% off global growth in the first year, largely because dearer oil shifts income from oil consumers to producers, who tend to spend less. For now any impact is almost certainly outweighed by improvements elsewhere, particularly in the easing of the euro crisis. Despite dearer oil, the prospects for global growth are still better than they were at the beginning of the year.

　　从全球角度来看，油价上涨带来的危害可能要小点。根据经验，油价持续上升１０％在第一年会削掉全球增长的０．２％，这主要是因为油老大把收益从消费者转移到了生产者，而生产者倾向于消费少点。对于现在，任何影响几乎都超过了其他方面的改善，尤其在欧债危机缓解上面。撇开油老大，全球经济前景还是比年初时候的好一些。

　　But the impact on growth and inflation in individual countries will differ. In America, a net importer which taxes fuel lightly, the standard rule is that a $10 increase in oil prices (which corresponds to a 25-cent rise in the price of petrol) knocks around 0.2% off output in the first year and 0.5% in the second year. That would slow, but hardly fell, an economy that is widely expected to grow by more than 2% this year.

　　不过，油价的影响对每个国家经济增长和通货膨胀的影响都是不一样的。美国，作为一个净输入国对油品征税较轻，一般规则是油价上升１０美元（相当于每公升涨25分）第一年的产出减少0.2%，第二年减少0.5%。这将令一个今年预期增长超过2%的经济体发展放缓，但不会倾覆。

　　There are in any case several reasons why America may be more resilient to dearer oil than in recent years. The jump in petrol prices has been far smaller than in 2011 or 2008. Rising employment gives consumers more income with which to pay for fuel. And America’s economy is becoming ever less energy-intensive, and less dependent on imports. Oil consumption has fallen in the past two years, even as GDP has risen.

　　无论如何，美国比过去几年对油老大都更有抗逆性是有一些原因的。现在的油价蹿升比11年和08年的都弱。美国经济不再是那么能源集中型的了，而且对进口的依赖也更小了。在过去的两年里，原油消耗减小了，但GDP依然增长。

　　Americans are driving less, and they are buying more fuel-efficient cars. Net oil imports are well below their 2005 peak, which means more of the money Americans spend on costlier oil stays within its borders. The development of copious amounts of natural gas means gas prices have plunged. That, coupled with an unusually mild winter, has kept bills for home heating unusually low. In January the share of consumers’ spending on energy products was the second-lowest in 50 years. These factors do not imply that America is impervious to spiking oil, but they do suggest the impact of price rises to date will be modest.

　　美国人更少开车了，而且他们也在购买节能型车辆。原油净进口量远低于05年的峰值，这就意味着美国人花在油老大身上的钱更多地留在了美国国内。对储量丰富的天然气的开发也意味着天然气价格的下降。尽管伴随着一个异常寒冷的冬天，这也令家庭取暖费非常低廉。一月份消费者在能源类产品上的支出比例为50年来的第二低位。这些原因虽然不能说明美国对于油价飚升的敏感性不强，但意味着目前油价上涨的影响需要重新评估。

　　Europe is more exposed. European countries, which tax oil more heavily than America, have typically seen a smaller impact on growth from changes in the oil price. But this time they may be relatively more affected, because most economies are already stagnant or shrinking. Worse, Europe’s weakest peripheral economies are also some of the biggest net importers (see chart 2). Greece, for instance, is highly dependent on imported energy, of which 88% is oil. Even the price rises to date will worsen the euro-zone recession; a big jump could spawn a deep downturn and fracture the confidence of markets.

　　欧洲则无所遁形。欧洲各国比美国对原油征税重，他们早就看到过油价变化对经济增长的一些影响。这次他们可能会受到更大的干扰，因为很多经济体已经陷入了萎缩和滞胀。更糟的是，欧洲一些衰弱的外围经济体还是几个最大的原油净进口国（见图二）。比如说希腊，高度依赖进口能源，其中的百分之八十八都是石油。即便是油价现在这个涨幅，也会使欧元区的衰退更加恶化；油价的一个大幅跃升可能酿成更深的衰退，同时也瓦解了市场信心。

　　Britain is relatively insulated. Although it is a net oil importer, it has significant resources in the North Sea. Any losses to the consumer from dearer fuel are partially offset by gains in the oil and gas sector itself. But even in Britain the net effect of price increases to date could be more damaging than usual, particularly since they reduce the odds of sharply falling inflation. Lower inflation, and a rise in real incomes, are one reason British policymakers hoped to see the economy improve this year.

　　英国是相对独立的。尽管它也是石油净进口国，不过在北海它有大量的资源。油老大对消费者带来的损失能被本国油气部门的收益所抵消。尽管如此，目前油价上涨影响对英国的危害也是非比寻常的，特别在它降低了通胀大幅下降的可能后。更低的通胀，就是实际收入的增加，是英国决策者今年希望看到的经济改善之一。

　　Barrels, no laughs.

　　筒子，别笑。

　　In emerging economies the picture is even more disparate. Oil exporters, from Venezuela to the Middle East, are gaining; oil importers will see worsening trade balances. In 2008 and 2011, the main effect of dearer fuel in emerging economies was on inflation. That is less of a worry now, largely because food prices, which make up a much bigger part of most emerging economies’ consumption basket, are stable.

　　在新兴经济体，情形更是千差万别。从委内瑞拉到中东，石油出口国都赚了，石油进口国将会看到更加恶化的贸易差额。在08年和11年，油老大在新兴经济体的主要影响表现在通胀上。现在就没那么担心了，这主要是因为，在新兴经济体消费篮子中比重剧增的食品价格比较稳定。

　　But some countries will face problems. In the short term, some of the hardest-hit emerging economies will be in eastern Europe. They will suffer not only from more expensive oil but also from the weakening of European export markets.

　　但是某些国家将会面临一些问题。短期来看，一些受到重创的国家将会在东欧。它们不仅要忍受高油价，还要遭受欧洲出口市场的恶化。

　　India is also a concern. Fuel is a big component of its wholesale-price index, for example, so inflation will rise as higher oil prices are passed through to domestic fuel costs. To the extent they are not, the budget will be hit. India regulates—and heavily subsidises—the price of diesel and kerosene. According to Deutsche Bank, diesel prices have risen by only 31% since January 2009, whereas the price of crude oil in rupees is up by 180%. The difference is a result of subsidies, frustrating India’s efforts to reduce its budget deficit.

　　印度也是个麻烦。举个例子，燃料是印度大宗商品指数的重要组成部分，因为油价会传导到国内燃料成本，所以通胀就会上升。到了承受不了的程度，预算会被重创。印度规范了——同时也着重补贴——柴油和煤油的价格。据德意志银行称，从09年一月起，按卢比计算的原油价格增长了180% ，而柴油价格只涨了31%。这个差距是补贴的结果，不过也浪费了印度缩减预算赤字的努力。

　　So oil is not the new Greece. More expensive oil is, for now, doing little harm to global growth. But it is not helping Europe’s more fragile economies. And if the Strait of Hormuz is threatened, the resulting surge in oil prices will spell the end of the global recovery.

　　所以，石油并不是新的希腊。目前来看，昂贵的石油几乎对全球增长没有什么危害，但它也没有帮助欧洲脆弱的经济。如果霍尔木兹海峡受到威胁，由此产生的油价飚升将为全球经济复苏画上一个休止符。