That is one reason these outfits sometimes work on other one-off big international events such as G7 meetings or world Expos.

ECONOMIST: The Olympic legacy

Chicago has had two world expos in its history, and both of those expos ended up being tremendous boosts for the city.

WHITEHOUSE: President Obama Holds Town Hall with Chinese Youth

The city's lavish spending on the expo is all the more striking given how lacklustre a brand World Expos (or World's Fairs as they are sometimes known) have become in the developed world.

ECONOMIST: The Shanghai World Expo