Austerity is an evil policy when not used when the economy is humming. This was done by Hawke in the 80s , Howard in the 90s and Clinton in the USA in the 90s. It worked in these cases just as Keynes said it would back in 1936!However used when the economy is weak it will lead to a recession or a depression ( a reduction in output of 10% or more).
Simon Wren-Lewis of Mainly Macro fame examines the link between austerity and mortality.
Yet another reason on why not use this policy in the wrong circumstances.