"One should have a wide variety of assets in one's portfolio. And oil, by the way, is a particularly ..." — Robert J. Shiller

In a bubble, eventually people start saying, 'Wait a minute... these prices are way too high! What is anyone buying anymore? What could they possibly be thinking?' And then there's a correction and a bursting.

Critics of 'economic sciences' sometimes refer to the development of a 'pseudoscience' of economics, arguing that it uses the trappings of science, like dense mathematics, but only for show.

Since the global financial crisis and recession of 2007-2009, criticism of the economics profession has intensified. The failure of all but a few professional economists to forecast the episode - the aftereffects of which still linger - has led many to question whether the economics profession contributes anything significant to society.

We should not be focusing on quick solutions. The really important concern for policymakers everywhere is to prevent disasters - that is, the outlier events that matter the most.