Australia ranks at number two on the list of countries described by Forbes magazine as "most likely to suffer a debt crisis" within the next three years. Australia follows China, which tops the list, and is followed by Sweden, Hong Kong, South Korea, Canada and Norway.Steve Keen, an academic with a bent for post-Keynesian economics, rehashed his model in a column for Forbes."The bottom line is that private sector expenditure in an economy can be measured as the sum of GDP plus the change in credit, and crises occur when (a) the ratio of private debt to GDP is large; (b) growing quickly compared to GDP. "When the growth of credit falls—as it eventually must, as growing debt servicing exhausts the funds available to finance it, new borrowers baulk at entry costs to house purchases, and numerous euphoric and Ponzi-based debt-financed schemes fail—then the change in credit falls, and can go negative, thus reducing demand rather than adding to it."This is what caused the Global Financial Crisis, Keen insists.