IMF get their maths wrong so we suffer far more than was predicted
The IMF calculated that every €100 of austerity would cost the economy €50 in lost growth and unemployment. This was deemed to make fiscal sense and, lo, the age of austerity was born.
Belatedly discovered “large and significant” errors in the IMF’s maths mean it underestimated the catastrophic impact of austerity by a factor of up to three. Oops.