Pat Ryan, chairman of insurance group Aon, took a long hard look at the T-shirt handed to him amid a crush of reporters in a cramped corner of the Macy’s department store in downtown Chicago.

Wisely, Mr Ryan did not attempt to pull the limited edition “Chicago 2016” shirt over his neat suit, but there are few things the city’s business community will not do to help bring the summer Olympics to the Midwest for the first time.