爱思英语编者按:“金发姑娘原则”源自童话《金发姑娘和三只熊》的故事:迷路了的金发姑娘未经允许就进入了熊的房子,她尝了三只碗里的粥,试了三把椅子,又在三张床上躺了躺,最后决定小碗里的粥最可口,小椅子坐着最舒服,小床上躺着最惬意,因为那是最适合她的,不大不小刚刚好。金发姑娘选择事物的原则被称作金发姑娘原则(Goldilocks principle)。

Putting Goldilocks to work

应用“金发姑娘原则”

A new study shows that climate change is likely to sap productivity in the rich world
一项新研究表明气候变化可能削弱发达国家的生产力
Oct 24th 2015 | From the print edition
 
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1“ALWAYS pack a sweater,” one local businessman advises visitors to Singapore, “because the best thing about our weather is the air conditioning.” Singapore’s first prime minister, Lee Kuan Yew, would have agreed—he considered the air conditioner the greatest invention of the 20th century. Another Singaporean politician once remarked that if it had not been for artificial cooling, local workers would be “sitting under coconut trees” rather than labouring away in high-tech factories.
 
“总是带一件毛衣,”一位当地商人建议来新加坡的游客,“因为关于天气最好的事情是空调。新加坡第一任总理李光耀会同意这个说法:他认为空调是20世纪最伟大的发明。其他的新加坡政治家曾经评论道,如果没有人工降温,当地工人可能坐在椰子树下而不是在高科技工厂里工作。
 
2Singapore is rich enough to keep its indoor spaces cool. Neighbouring Indonesia is not. Economists used to think that rich countries’ greater cooling power would enable them to limit the damage to their economies from the higher temperatures brought by global warming. A cross-country comparison published in 2012 found that higher temperatures did not seem to sap growth in rich countries, but did in poor ones. It is hard to compare the impact of temperature on growth in hot and cold countries directly, since there are too many variables to control for. Instead, the study compared growth in a given country during hot years with that during colder ones. It found that in poor countries, on average, higher temperatures were associated with slower growth. But some rich countries grew faster in hot years, and some in cold ones, suggesting that there was no clear correlation between temperature and growth in the developed world.
 
新加坡有足够的钱来保证室内低温,旁边的印度尼西亚却不能。经济学家过去认为,发达国家强大的降温能力能使他们限制由全球变暖带来的高温导致的经济上的损失。2012发表年的国家间的比较发现,高温似乎没有削弱发达国家的经济增长,反而削弱了贫穷国家。很难直接比较在炎热和寒冷国家温度对于经济增长的影响,因为有太多变量需要控制。此外研究比较了特定国家在热年份和冷年份的经济增长。发现在贫穷国家,通常更高的温度与更小的经济增长有关。但是一些富裕国家在热年份增长更快,另一些则是在冷年份,这表明温度和经济增长在发达国家没有明显联系。
 
3A paper published this week in Nature challenges this finding. The authors—Marshall Burke, Solomon Hsiang and Edward Miguel—suspected that economists had been looking for the wrong thing: a linear relationship between temperature and growth. Instead, they looked for an optimal temperature, on the assumption that excessive cold could harm growth as much as punishing heat. That is exactly what they found: hotter-than-usual years benefit countries, rich and poor alike, up to an average annual temperature of 13°C, after which hotter weather begins to sear growth. That allowed them to draw inferences about the likely effect of climate change: for Brazil, for example, an increase in temperature of 3°C will lead to a fall in output of 3% (see chart).
 
本周刊登在《自然》上的文章挑战这个结果。文章的作者——马尔谢•伯克,所罗门•祥和爱德华•米格尔——怀疑经济学家过去找到了错误的事:温度和经济增长之间的线性关系。反而,他们找到了一个理想温度(假设过多的降温可能和严酷的热一样会削弱经济增长)。那正是他们发现的:比平常更热的年份有利于发达国家和贫穷国家,平常年份年平均温度13℃,超过这个温度后高温开始削弱经济增长。他们对气候变化的可能影响举一反三:比如巴西,3℃的增长会导致降低3%的出口(如图)
 
4The apparent heat resistance of rich countries, it turns out, is simply because some of them, such as Germany and France, lie on the colder side of the optimum, so grow faster in hotter years, whereas others, such as America and Australia, lie on the hotter side, and so wilt as temperatures rise. Within individual counties in America, for instance, every hot day (with an average temperature over 24 hours of 24-27°C) lowers the average income per person that day by 20%, according to a working paper from the National Bureau of Economic Research by Mr Hsiang and Tatyana Deryugina. Very hot days (over 30°C) lower income per person by 28%. Looking at the average impact of rising temperatures in rich countries as a group had obscured such strong responses.
 
其实发达国家显著的耐热性,仅仅是因为他们中的一些国家,比如德国和法国,处于最佳的寒冷位置,因此在热年份增长很快。而另一些国家比如美国和澳大利亚,处于较热的地方,经济随着温度上升而放缓。例如美国个别县内,根据国家经济调查局的所罗门•祥和塔基亚娜•德维于吉娜的工作报告,每个炎热天气(24小时平均温度在24-27℃)降低了20%的人均收入,非常炎热的天气(超过30℃)降低了28%的人均收入。 气温上升在发达国家的平均影响作为一个群体挡住了如此强烈的反应。
 
5Ironically, the fact that global temperatures are changing has prompted some economists to question these results, since it means there is no firm baseline for comparison. But there is plenty of evidence for an optimal temperature at the micro level. Crops, for example, flourish when it is neither too hot nor too cold. Workers, too, do better in mild settings. The British navy commissioned the first research on temperature and productivity in the 1940s. In one experiment, Morse-code operators were placed in rooms of varying temperature. Those in rooms heated to 40°C made more than ten times more errors than those in rooms that were 30°C.
 
讽刺的是,全球变暖的事实促使一些经济学家质疑这些结果,因为他意味着没有严格的基线作比较。但在微观层面有最适宜温度的大量证据。比如农作物在不冷也不热的时候生长茂盛。工人也是如此,在适宜的温度做的更好。1940年英国海军委员委托了温度和生产力的第一次研究。一次实验中,摩斯密码员被放在温度变化的房间里。他们在房间40℃高温时比房间30℃多犯十次错误。
 
6In a similar vein, a paper published in the Journal of Labour Economics last year found that American workers in construction, manufacturing and transport knocked off earlier when the temperature rose above 29°C, working an hour less per day on average. As the incidence of hot days increases, either more workers will be needed to finish the same project, or workers will need to be paid more to persuade them to stay on, just as workers are paid extra for the inconvenience of night shifts. Industries in which workers are exposed to the weather employ 28% of America’s workforce, according to a recent study looking at how climate change will affect America’s economy.
 
同样的,去年刊登在《劳动经济学杂志》的文章表明,当温度上升至29℃时,建筑业,制造业和运输业的美国工人提前停工了,平均每天工作少于1小时。因为炎热天气的影响会增加,要么是需要更多的工人来完成同样的项目,要么是需要支付工人更多报酬来让他们,因为需要额外支付工人夜班不便的费用。根据最近的一项关于气候变化将如何影响美国经济的研究,需要工人室外工作的行业雇佣了美国28%的劳动力。
 
Cool but costly
冷但是贵
 
7Countries can try to mitigate the effects of warming, but cooling things down is expensive. In Singapore, air conditioning consumes 40% of the power used in buildings. If nothing is done to stop global warming, the world will see an 83% increase in electricity consumption between 2010 and 2100, due simply to greater use of air conditioning, fans and refrigeration, according to a paper published in the journal PNAS in March by Lucas Davis and Paul Gertler. Richard Tol of the University of Sussex points out that homes and offices in cold countries are built to conserve heat, with large south-facing windows. Refurbishing such buildings could help keep people cool, but at great cost.
 
许多国家试图缓和变暖的影响,但降温是昂贵的。在新加坡,空调消耗了40%建筑物的电力。根据卢卡斯戴维斯和保罗格特勒4月发表在《美国科学院院刊》的文章,如果对全球变暖什么都不做,仅由于空调,电风扇和制冷的大量使用,2010年到2100年之间世界上电力消耗将增加83%。苏塞克斯郡的理查德托尔指出,有着朝南大窗户的家庭和办公室被建成来保留热量。
 
8There are many other ways, of course, that global warming will harm rich countries besides falling productivity tied to higher temperatures. Climate change will not only heat up the planet, but will also lead to sea-level rises and an increase in extreme weather, such as hurricanes. Since many big cities are on the coast, they will require protection. Environmental economists have already been working for decades on Doomsday calculations, such as whether it would be better to build costly flood defences for Singapore’s business district or let it be inundated.
 
全球变暖将损害发达国家,除了高温带来的生产力下降,当然也有许多其他影响。气候变化将不仅使星球升温,也会导致海平面上升和极端天气的增加。因为许多大城市沿海,所以它们需要被保护。环境经济学家针对世界末日进行数十年的计算,比如为新加坡商业区建立昂贵的洪灾防御工程或让它被淹没,那个更好一些。
 
9Moreover, even if rich countries manage to fend off the worst effects of global warming, they will still feel its repercussions. Trade with more vulnerable places would decline; refugees would proliferate. The Paris climate conference this December is supposed to come up with policies to avoid such outcomes. The new findings on the baleful impacts of high temperatures should give rich countries an extra incentive to compromise.
 
而且,即使发达国家能避开全球变暖带来的坏影响,他们仍会感受到其他影响。易受影响的地方的贸易会下降;难民会激增。今年12月的巴黎气候会议应该想出政策来避免这种结局。高温有害影响的新发现应该给发达国家额外的刺激去解决问题。
From the print edition: Finance and economics
 
【译注】
“金发姑娘原则”源自童话《金发姑娘和三只熊》的故事。金发姑娘发现了三只熊的房子,每只熊都有自己喜欢的食物和床。在挨个尝试过三只熊的食物和床后,金发姑娘发现有一个要么太大/太热,一个要么太小/太凉,只有一个是“刚刚好”。在天文学里,“金发姑娘地带”指的是一个星球周围的宜居地带。在经济学里,“金发姑娘经济”指的是维持适度增长和低通胀的经济。