"It was China’s former leader, Deng Xiaoping, who urged his countrymen to “seek truth from facts”. But for the many in China who distrust government data, that sage advice can be hard to follow. In the case of official reports about the improving air quality in Chinese cities, however, taking Mr Deng’s advice is easier. To evaluate a specious government report of yet another “blue-sky day”, you need only look out the window, sniff the air, or—for the brave—take a deep breath." (Quoted from article)