经济学人下载:全球一线城市房价暴涨 究竟是什么在操控着房价?

Whenever the supply of a good is limited, there is potential for exuberance.
一种商品供给的有限性总是伴随着繁荣的潜在性。

San Francisco's property market is intertwined with the technology sector: since 2008 there has been a 93% correlation between the monthly movements in the NASDAQ and house-price inflation in its metropolitan area.
旧金山房地产市场与技术部门关系紧密，自2008年起，美国全国证券交易商协会自动报价系统每月93%的运作与市区房价高涨相关。

Since bottoming out in early 2012, prices in Silicon Valley have risen by 73%, compared with 31% in America as a whole.
自2012年早期房价触底回升以来，硅谷的房价与全国总体水平31%相比上涨了73%。

To determine whether homes are fairly valued The Economist looks at the relationship between prices and disposable income (an indicator of affordability) and between prices and rents (a substitute for buying a home) .
为了查明房价是否合理，经济学人杂志看了看价格与可支配收入（衡量支付能力的指标）和租房（买房行为的替代品）两者的关系。

If rising prices move these ratios above their long-run averages, then either incomes or rents are likely to rise, or house prices to fall.
如果价格上升推动这些比率上升至其长期平均水平之上，那么要么是收入和租金可能增加，或是房价下落。

Across America house prices, after falling by 25% from their peak between 2007 and 2012, are now at fair value compared with rents and incomes.
在2007年到2012年间，全美房价从最高点下落了25%，如今房价收入比和房价租金比已处于公允价值。

In San Francisco, too, they are at fair value when compared with rents, but 45% overvalued relative to incomes.
旧金山的房价租金比也是如此，但是房价收入比高估了45%。

Thanks largely to their big cities, housing appears to be more than 40% overvalued in Australia, Britain and Canada, according to the average of our two measures.
两种计量方法得出的平均值显示，澳大利亚、英国、加拿大住房价格似乎被高估了40%以上，这很大程度归功于这些国家的大城市。

Between 2002 and 2012 the typical London home sold for seven times the city's average annual salary. That figure has since risen to 12 times.
2002年到2012年间，伦敦普通住房的售价是全国居民年平均收入的7倍，而这个数字目前已增长了12倍。

As property developers from Las Vegas to Limerick will attest, when supply does eventually respond to soaring demand, property prices fall.
当供给最终对日益膨胀的需求作出回应的时候，房地产价格就会下落。拉斯维加斯和利默里克的房地产开发商们会证实这一点。

Restrictive planning laws curb new construction in the area around San Francisco Bay; the narrow peninsula that San Francisco itself occupies compounds the problem.
严格的规划法规抑制了旧金山海湾地区新住房的建设；旧金山所在半岛的狭小加剧了这一问题。

London suffers from an even more severe planning regime.
伦敦的规划制度更加严厉。

Yet housing starts are at a nine-year high in San Francisco.
然而旧金山的房屋开工率是9年来最高的。

In London, too, builders are finding a way: construction began on 24,000 new homes in the capital in 2015, the highest rate for ten years.
伦敦同样也找到了解决办法：2015年该市24000所住房开始进入施工阶段，创10年新高。