But you can't do it without some kind of economic signals, in the form of a carbon tax.

但如果没有碳排放税形式的某种经济信号，同样无法实现。

There is a large, growing literature on how to decode economic signals from social-media sites, ranging from Facebook to Reddit.

关于如何破译Facebook和Reddit等社交媒体网站的经济信号的文献有很多，而且数量还在不断增加。

Powell says he and his colleagues will continue to monitor economic signals, which he's described in the past as murky.

鲍威尔表示，他和同事将继续监测经济信号，鲍威尔此前曾称这些信号模糊不清。