Houses became much more expensive in California than in the rest of the country during this decade's housing boom, with the gap growing until early 2007, when most of those emigrating today would have begun to make their plans.

ECONOMIST: Emigration from California

"While not suitable for everyone, housing with care can potentially fill a gap between mainstream homes and care homes for some people with dementia, " spokeswoman Kathy Milosevic said.

BBC: Newton Abbot 'extra care' homes for dementia sufferers

National Statistician Jil Matheson said that the absence of a UK-wide official private rental index was a "key gap" in data on the housing market.

BBC: Lettings boards

"With the concerns that public expenditure is declining significantly, which would then limit the ability of the Housing Executive to maintain and improve its housing stock, private money would fill that gap, " Mr Hoodless said.

BBC: News

If the above is not enough, it must be remembered about Paulson that, if the markets had been allowed to work their magic, that his successful bet against housing would have very much reduced the lifestyle gap that is always the certain result of economic achievement.

FORBES: The Life Enhancing, Unrelenting Brilliance of Income Inequality

Liberal Democrat vice-chair Stephen Knight said there was a "credibility gap" in the mayor's housing plans.

BBC: Drop in London's affordable homes build in 2012

Other data sources have blamed the lingering employment woes on a gap in the skills needed and those available, geographical constraints tied to the still-difficult housing market and the increase in the number of people dropping out of the workforce, a trend that is tied to an aging population.

FORBES: Why aren't companies hiring?