Mainstream Keynesian economics is caught in a trap of its own making, a bit like the Keynesian liquidity trap in a zero lower bound interest rate economy. Let me explain. In my view, there are two great merits of Keynes’ contribution to understanding an economy. The first was a return to analysing an economy in its aggregate, not at the level of individual consumer’s or firm’s behaviour or preferences. This meant that the fluctuations in a capitalist economy could be considered in their whole and not just ignored or dismissed. In other words, macroeconomics replaced microeconomics.