This is an interesting, though esoteric, essay from the Financial Times. As the FT asks not to re-post articles I have included the link.
Here are a few excerpts:
Even if sharp predictions of individual economic outcomes are rarely possible, it should be possible to describe the general character of economic events, the ways in which these events are likely to develop, the broad nature of policy options and their consequences. It should be possible to call on a broad consensus on the interpretation of empirical data to support such analysis. This is very far from being the case.
The two branches of economics most relevant to the recent crisis are macroeconomics and financial economics. Macroeconomics deals with growth and business cycles. Its dominant paradigm is known as “dynamic stochastic general equilibrium” (thankfully abbreviated to DSGE) – a complex model structure that seeks to incorporate, in a single framework, time, risk and the need to take account of the behaviour of many different companies and households.
The study of financial markets revolves meanwhile around the “efficient market hypothesis” – that all available information is incorporated into market prices, so that these prices at all times reflect the best possible estimate of the underlying value of assets – and the “capital asset pricing model”. This latter notion asserts that what we see is the outcome of decisions made by a marketplace of rational players acting on the belief in efficient markets.
A close relationship exists between these three theories. But the account of recent events given by proponents of these models was comprehensively false. They proclaimed stability where there was impending crisis, and market efficiency where there was gross asset mispricing.
Economics is not a technique in search of problems but a set of problems in need of solution. Such problems are varied and the solutions will inevitably be eclectic. Such pragmatic thinking requires not just deductive logic but an understanding of the processes of belief formation, of anthropology, psychology and organisational behaviour, and meticulous observation of what people, businesses and governments do.