Flat Earth: Boom industry

LAST week a couple of hundred people were milling around a big Washington hotel, looking for a symposium on new ideas for reviving American cities. A small, easily-missed sign directed them to the hall on the right.

Delegates turning up to another meeting on coping with life in US cities did not have the same trouble finding their venue. A much bigger and more prominent signboard told them to go straight ahead for the rival gathering: the annual conference of vendors of bulletproof vests.