Chinese Workers Abandon Silicon Valley for Riches Back Home

Look at the history: shanghai dipped orange and red multiple times in the past few days, while SF just dipped into the yellow.

https://aqicn.org/city/shanghai/

http://aqicn.org/city/california/san-francisco/san-francisco...

Keep in mind it’s also night in china ATM while it is noon in SF.

Shanghai is much worse than SF on average. It dips into the red zone more often, retreating when it rains. Shanghai is much better than the rest of china barring Shenzhen, Xiamen, and maybe Kunming, but it would still come across to an American visitor as smoggier than they were used to.