House prices are now starting to fall after years of vertiginous growth. And it is overheated markets, overheated markets, like those in Australia, Canada and Sweden, that are facing some of the sharpest drops. A mortgage binge fuelled by rock-bottom interest rates has left each country with enormous quantities of household debt. As a share of disposable income, such debt sits at 185% in Canada, 202% in Australia and 203% in Sweden. By contrast, debt levels have shrunk in countries that bore the brunt of the last crash, including America, Ireland and Spain (see chart).ver·tig·i·nous: /vərˈtijənəs/ adjective, causing vertigo, especially by being extremely high or steep.