¿Por qué ha fallado la macro?

De Frances Coppola. ¿Por qué ha fallado la macroeconomía? No se puede decir mejor en tan pocas palabras (negritas mías). REF: Krugman, "Acabad con esta crisis ya":

The failure of most macroeconomists to foresee the financial crisis grew out of their incorrect understanding of how money is created, and perhaps more importantly, how leverage builds up. "Loanable funds" models, which portray the role of the financial sector as intermediating existing funds, are not only wrong, they are dangerous. They do not show how exuberance in credit creation arising from the irrational belief that asset values can keep rising forever carries the seeds of its own destruction. And they encourage belief in exogenous factors as the cause of financial crises – the "Asian savings glut" springs to mind. The huge increase in broad money prior to the financial crisis did not come from Asia, or from Mars. It was created by American and European banks.
Leaving banks out of economic models, or – worse – modelling their money-creating function incorrectly, made it impossible for mainstream economists to understand the significance of the build-up of credit that led to the financial crisis. The warnings came principally from people outside mainstream economics, particularly the followers of Hyman Minsky. After the crisis, Minsky’s "financial instability hypothesis", long consigned to a dusty shelf in a dark cupboard, suddenly became hot news. Unsurprisingly, since we had just lived through something that looked very like a "Minsky moment".
Clearly, the exclusion of the financial industry from models of the macroeconomy was a major omission. Equally clearly, the fact that most macroeconomists did not, and to a large extent still do not, understand the mechanisms by which money is created and circulated in the modern monetary economy, is a big, big problem. Central banks are now "adding" the financial sector to existing DSGE models: but this does not begin to address the essential non-linearity of a monetary economy whose heart is a financial system that is not occasionally but NORMALLY far from equilibrium. Until macroeconomists understand this, their models will remain inadequate.