The entry of China, India and the former Soviet Union into market capitalism has, in effect, doubled the world supply of workers, from 1.5 billion to 3 billion.

ECONOMIST: More pain than gain

The integration of China and other emerging economies into the world trading system has, in effect, more than doubled the global labour force, and by curbing workers' bargaining power it has restrained pay demands in most developed economies in recent years.

ECONOMIST: Why China is not to blame for the surge in global inflation

Since the mid-1990s, when tough state parity laws started taking effect, enrolment in managed mental health plans has doubled to 140 million.

FORBES: Asylum for The Insane

Marty Quinn's half-time words had the desired effect as Glenavon grabbed the winning goal and should have doubled their lead after 86 minutes but Willo McDonagh's effort hit the outside of the post.

BBC: Institute 0-1 Glenavon

The number of machines has nearly doubled, from 139, 000 in 1996, when the surcharges first took effect, to 227, 000 today.

CNN: The War on ATM Fees