US Chinatowns are shrinking, and while some want to fight, new ones are springing up

In San Francisco’s Chinatown, the oldest hub of Chinese-owned businesses in the United States, vacancy signs pockmark the district’s dining establishments, gift shops and herb stalls.

And at a Chinatown across San Francisco Bay in Oakland, rampant storefront graffiti and the fear of robbery chill the daily bustle of kerbside grocery shopping.