The average UK family faces at £2,000 plunge in income. New data from the Institute for Fiscal Studies (IFS) is predicting that consumer spending power will slump 7% between 2010 and 2013. For the average family this is a sharp knock. In fact, the greatest slump in disposable income since the 1970s. And it could take till 2015 before many households recover spending power they had in 2009.