【英语财经】低油价是经济增长的福音吗？ The consequences of cheap oil

After years in which $100 oil was the norm, the price of Brent crude is now around a third of that. Assume for a moment that Russia and Saudi Arabia fail in their efforts to get the price back up. Will $30 oil change the world? The answer is yes, of course. Everything is connected to everything else in economics, and that is particularly true when it comes to oil. For all the talk of the weightless economy, we’re not quite so post-industrial as to be able to ignore the cost of energy. Because oil is versatile and easy to transport, it remains the lubricant for the world’s energy system.

The rule of thumb has always been that while low oil prices are bad for the planet, they’re good for the economy. Last year a report from PwC estimated that a permanent fall in the price of oil by $50 would boost the size of the UK economy by about 1 per cent over five years, since the benefits — to most sectors but particularly to heavy industry, agriculture and air travel — would outweigh the costs to the oil production industry itself.

That represents the conventional wisdom, as well as historical experience. Oil was cheap throughout America’s halcyon years of the 1950s and 1960s; the oil shocks of the 1970s came alongside serious economic pain. The boom of the 1990s was usually credited to the world wide web but oil prices were very low and they soared to record levels in the run-up to the great recession. We can debate how important the oil price fluctuations were but the link between good times and cheap oil is not a coincidence.

Here’s a piece of back-of-the-envelope economics. The world consumes nearly 100 million barrels a day of oil, which is $10bn a day — or $3.5tn a year — at the $100 price to which we’ve become accustomed. A sustained collapse in the oil price would slice more than $2tn off that bill — set against a world economic output of around $80tn, that’s far from trivial. It is a huge transfer from the wallets of oil producers to those of oil consumers.

Such large swings in purchasing power always used to boost economic growth, because while producers were saving the profits from high prices, consumers tended to spend the windfall from low ones. One of the concerns about today’s low prices is that the positions may be reversing: the big winners, American consumers, are using the spare cash to pay off debts; meanwhile, losers such as Russia and Saudi Arabia are cutting back sharply on investment and public spending. If carried to extremes, that would mean a good old-fashioned Keynesian slowdown in a world economy trying to spend less and save more; the more likely result of which is that lower oil prices fail to give us the boost we hope for.

It is intriguing to contemplate some of the less obvious effects. Charles Courtemanche, a health economist at Georgia State University, has found a correlation between low gasoline prices and high obesity rates in the United States. That is partly because, when oil prices are high, people may get out of their cars and walk, cycle or get public transport. Cheap gasoline, on the other hand, puts disposable income into the pockets of families who are likely to spend it on eating out. Low oil prices may make us fat.

Another depressing possibility is that low oil prices will slow down the rate of innovation in the clean energy sector. The cheaper the oil, the less incentive there is to invent ways of saving it. There is clear evidence for this over the very long run. As recently as the late 1700s, British potters were using wasteful Bronze Age technology for their kilns. The reason? Energy was cheap. Wages, in contrast, were expensive — which is why the industrial revolution was all about saving labour, not saving energy.

More recently, David Popp, an economist at Syracuse University, looked at the impact of the oil price shocks of the 1970s. He found that inventors emerged from the woodwork to file oil-saving patents in fields from heat pumps to solar panels.

It is always possible that the oil price collapse will do little to affect some of the big technological shifts in the energy market. The scale of oil production from hydraulic fracturing (fracking) in the US may be curtailed but a huge technological leap has already happened. As the chief economist of BP, Spencer Dale, recently commented, fracking is starting to look less like the huge, long-term oil-drilling projects of the past, and more like manufacturing: cheap, lean, replicable and scalable. Low oil prices cannot undo that and the efficiencies may well continue. We can hope for ever-cheaper solar power too: photovoltaic cells do not compete closely with oil, and we may continue to see more and more installations and lower and lower prices.

That said, when fossil fuels are cheap, people will find ways to burn them, and that’s gloomy news for our prospects of curtailing climate change. We can’t rely on high oil and coal prices to discourage consumption: the world needs — as it has needed for decades — a credible, internationally co-ordinated tax on carbon.

Tim Harford is the author of ‘The Undercover Economist Strikes Back’.

在许多年里，每桶石油在100美元以上是常态，如今，布伦特(Brent)原油价格只有那个水平的三分之一左右。假设俄罗斯与沙特阿拉伯短时间内无法让油价回升，每桶30美元的油价会改变世界吗？当然，答案是肯定的。在经济学中，一切因素都彼此关联——对石油来说就尤其如此了。虽然大家都在谈论“无重量经济”(weightless economy)，但我们的后工业化水平还没有达到可以忽略能源成本的程度。因为用途广泛且易于运输，石油仍是全球能源系统的润滑剂。

经验法则告诉我们，低油价虽然对地球不是好事，却有利于经济发展。去年，普华永道(PwC)发布的一份报告估计，油价长期性地跌去50美元，将使英国经济规模5年内扩张1%左右，因为低油价给大多数行业——尤其是重工业、农业及航空业——带来的好处将超过石油生产行业本身所遭受的损失。

这既是一般观点也是历史经验。上世纪五、六十年代美国歌舞升平时期，油价始终都很便宜；70年代的石油危机伴随着严重的经济危机。90年代的繁荣通常被归功于互联网，其实油价当时很低，后来在“大衰退”前夕才飙升到了创纪录水平。我们可以争论油价波动的重要性，但繁荣时期与廉价石油之间的关联并非巧合。

我们可以粗略地算一下：全世界每天消耗近1亿桶石油，按照我们习惯的每桶100美元计算，每天需要花费100亿美元，一年下来是3.5万亿美元。油价持续暴跌将使这笔开支减少逾2万亿美元，而与80万亿美元左右的世界经济产出相比，这并非微不足道。这是一笔从产油国转移至石油消费国的巨额财富。

购买力方面的大幅变动在过去通常会刺激经济增长，因为生产商会把从高价中获得的利润储蓄起来，而消费者则倾向于花掉从低价中节省下来的钱。当前低油价令人担忧的一个地方是，情况可能颠倒了过来：作为大赢家的美国消费者正在利用省下的钱偿还债务；与此同时，俄罗斯、沙特等输家正在大幅削减投资及公共支出。如果发展到极端，人们都试图减少开支、增加储蓄，世界经济将出现一场传统的凯恩斯式放缓；这样的后果是，低油价很可能无法带来我们期待的经济刺激效果。

低油价还有一些不那么明显的影响很是耐人寻味。乔治亚州立大学(Georgia State University)健康经济学家查尔斯?库特芒希(Charles Courtemanche)发现，美国汽油价格低企与高肥胖率之间存在相关性。部分原因在于，油价高时，人们可能减少开车，选择步行、骑自行车或乘坐公共交通工具。另一方面，廉价汽油为家庭节省了可支配收入，而他们很可能把这些钱花在外出就餐上。低油价可能会让我们变胖。

另一个令人沮丧的可能性是，低油价会阻碍清洁能源领域的创新步伐。油价越便宜，发明新的节油方法的动力就越小。在这方面，历史上有明显的证据。18世纪头十年末期的时候，英国陶艺坊烧窑时使用的还是耗能很高的青铜时代的技术。原因何在？能源很便宜。相比之下，工资较高——这就是为什么工业革命的所有发明围绕的都是节约劳动力，而非节省能源。

最近，锡拉丘兹大学(Syracuse University)经济学家大卫?波普(David Popp)研究了上世纪70年代石油危机造成的影响。他发现，当时大批发明家申请了从加热泵到太阳能电池板等领域的节油专利。

始终存在这样的可能性，油价暴跌不会对能源市场中一些重大技术变革造成影响。在美国，利用水力压裂技术生产石油的规模可能有所缩减，但一场巨大的技术飞跃已经发生。英国石油(BP)首席经济学家斯宾塞?戴尔(Spencer Dale)最近称，水力压裂技术看起来已不再像过去那些庞大、长期的石油钻探项目，而开始更像制造业：廉价、精益、可复制、可扩展。低油价不会破坏这一进程，其效能将很好地延续下去。我们也可以寄希望于更廉价的太阳能：光伏电池还竞争不过石油，我们或许将看到越来越多的太阳能设备，以及越来越低的太阳能电价。

尽管如此，当化石燃料价格较低时，人们会找到各种方法利用它们，这对我们减缓气候变化的前景来说不是好消息。我们不能依靠高昂的石油和煤炭价格来抑制消费：世界需要（几十年来一直需要）一个可靠的、国际协调的碳税体系。

本文作者蒂姆?哈福德(Tim Harford)著有《卧底经济学家反击战》(The Undercover Economist Strikes Back)。

译者/隆祥