"There is never any sourcing of the number, " says Ira Mayer, publisher of the newsletter Marketing to Women, which in 2009 tried and failed to find its origin.

WSJ: Who Makes the Call at the Mall, Men or Women?

Returning to the money issue, if they say they were en route to the US to find work because of the harsh conditions in their country of origin, where did they get the money to do all this?

CENTERFORSECURITYPOLICY: Iraqi-American smuggling ring in Peru

Gamers struggled to download the game from the Origin servers and, once they had it, they struggled to find a server with enough room for them.

FORBES: Maxis Working to Fix SimCity's Server Problems

If you have a temperature of 101 F (38.3 C) or higher for more than three weeks and your doctor isn't able to find the cause after extensive evaluation, the diagnosis may be fever of unknown origin.

CNN: Fever

The authors find that when a prominent researcher moves from one city to another, his peers in the origin city are less likely to cite his patents.

ECONOMIST: Free exchange