In other words, Silicon Valley has yielded to global forces, but it remains vital in manufacturing because it s still the hub.

FORBES: Made In Silicon Valley

Because Heathrow is the UK's only hub airport, it has shown some resilience in the downturn, as passengers continued to fly into the airport before connecting to other destinations.

BBC: Heathrow enjoys passenger pick-up

Because it makes much of its income from organising corporate events, being in an international business hub has proved crucial to Duplays' success, while Dubai's tax-free status has not hurt either.

BBC: Expats see business boom in Mid East