在经济学里,有一种和天气息息相关的效应,叫作“一度效应”。它说的是,只要气温有1℃的变化,某些商品的销量也会随之发生很大的改变,尤其是那些与气温关联性很强的商品。盛产啤酒的德国曾在夏天统计过啤酒的销量,结果发现,每当夏季的气温上升一度,啤酒的销售量便会随之增加230万瓶之多。在对这种效应进行考察时,研究人员发现了一个很奇妙的现象,那就是当气温超过29℃而低于31℃时,雪糕要比冰激凌卖得好;一旦温度高于 In economics, there is a kind of effect closely related to the weather, called “once effect ”. What it says is that as long as the temperature changes by 1 ° C, the sales of certain products will change drastically, especially those associated with the temperature. Germany, which produces beer, counted sales of beer in the summer and found that sales of beer increased as much as 2.3 million bottles each summer when the temperature rose. In examining this effect, the researchers found a very curious phenomenon, that is, when the temperature exceeds 29 ℃ but below 31 ℃, ice cream sold better than ice cream; once the temperature is higher than