Do tariffs work?

With trade tensions between the US and China flaring up again, the spotlight is on how their game of mutually assured disruption plays out.

- 

As China had pre-existent problems, it may seem more vulnerable. In the three months till the end of September, China’s economy grew just 4.8%, its weakest pace in a year. It could have been worse had a temporary trade truce not been struck earlier this year; Chinese exports to the US are down but not out. But with B