Simon Wren-Lewis discusses the large gap between mainstream and heterodox economics, and asks why the heterodox economists are so willing to throw out almost every aspect of neoclassical theory. Allow me to offer an explanation.
The reason heterodox economists remain dissatisfied with mainstream economics, no matter how many modifications the latter adds to its core framework, is that there is always an implication that, in the absence of various real world ‘frictions’, the economy would function like a smoothly oiled machine. That is: assuming perfect information, mobility, ‘small’ firms, no unions, flexible prices/wages and so forth, the economy would achieve full employment, with near perfect utilisation of resources, and stay there, perhaps buffeted by mild external shocks.
New Keynesians and New Classicals sometimes act like bitter rivals, but mainly they only differ on which ‘frictions’ should be present or not (this is an oversimplification of the disagreement, of course). The original New Classical models started with economies that are always in equilibrium, preferences are constant, and competition is perfect. New Keynesian models add imperfect competition, sticky prices, transaction costs and so forth. The newest papers go further and add heterogeneous agents (which generally means two), changing preferences, and other ‘frictions.’ However, it is assumed that if the economy were rid some specific features/characteristics, it would function similarly to one of the core Walrasian or Arrow-Debreu style formulations.
So is it not true that real world mechanics prevent things from going as smoothly as they might do in absence of those mechanics? Well, partially. But according to heterodox economists, capitalism has inherent tendencies to crisis, unemployment and misallocation anyway.
A key example of where this is evident is finance. Generally the mainstream analyses of why finance is unstable focus on irrationality, imperfect information, externalities and other such modifications. If only everyone had access to information, if transactions were cost less, and if people were rational self maximisers, then finance would be stable.
Minskyites, on the other hand, argue that this isn’t the real problem. Even if the economy starts stable, the resultant strong returns on investments will cause capitalists/investors to take more risk. This process will continue and the economy will endogenously destabilise itself as higher returns are sought and more risk is taken on, until eventually the capacity to make a return on these risks is outrun and we face a collapse. There is no need to invoke a specific ‘friction’ for this process to occur.*
Another prominent example is the labour market. Generally, economists presume that without ‘search costs’, oversized firms/unions and sticky wages, the economy would achieve full employment. But heterodox economists disagree on a number of counts: the Marginal Value Product Theory is faulty, so higher wages will not necessarily cause unemployment to rise; wages are also an essential component of aggregate demand, so reducing them may well be counterproductive. In fact, Keynes argued that sticky wages were far from a barrier to full employment; they actually stabilised aggregate demand. Steve Keen’s model also produces less severe business cycles when sticky wages and prices are added.
So the reason heterodox economists want to throw the proverbial baby out with the bath water (and also redecorate the bathroom and possibly even move house, or something), is that they think the core of mainstream economics has dug itself too deep into a ditch. The inevitable ad hoc modifications of ‘perfect’ models sometimes have so many ‘frictions’ introduced that the supposed ‘deep’ mechanics that underlie them become questionable. But they are still never abandoned. Heterodox economics is not just about adding a few real world mechanics here and there; it’s about throwing out the entire core and starting over.
*It could be said that this might not occur if Knightian uncertainty were not a factor in the real world, but I think calling this a ‘friction’ jumps the gap between friction and fundamental reality.