The Icelandic Central Bank said that for nearly a quarter of all households in the country, the total debt service for mortgages, car loans and overdraft loans had exceeded 40% of disposable income, commonly considered the "danger limit" for total debt service.

FORBES: Global Economy

Total interest payments on household debt in Britain fell to 7% of disposable income at the end of last year, the lowest level since 2003.

ECONOMIST: House prices

They add up to disposable personal income, and then other adjustments are needed to take you the rest of the way to total GDP.

FORBES: The Income Side of GDP