Who benefitted from the bubble while it was going on? If your income is strongly correlated with asset prices you will benefit when there is a bubble and hurt in the crash. You will also have a short-term incentive to encourage a bubble. You are likely to favour policies which will lead to bubbles. The professional class is also better politically connected than other classes (and lots of the politicians are professionals) and so they have a disproportionate amoutn of political influence.

En un viejo país ineficiente, algo así como España entre dos guerras civiles, poseer una casa y poca hacienda y memoria ninguna. -- Gil de Biedma