‘New Keynesianism’ — little new and nothing Keynesian15 February, 2016 at 14:49 | Posted in Economics | Leave a comment
Not that long ago, Paul Krugman had a post up on his blog discussing ‘New Keynesian’ macroeconomics and the definition of necoclassical economics:
Most of what I and many others do is sorta-kinda neoclassical because it takes the maximization-and-equilibrium world as a starting point or baseline, which is then modified — but not too much — in the direction of realism …
New Keynesian models are intertemporal maximization modified with sticky prices and a few other deviations …
Why do things this way? Simplicity and clarity. In the real world, people are fairly rational and more or less self-interested; the qualifiers are complicated to model, so it makes sense to see what you can learn by dropping them.
Being myself sorta-kinda Keynesian, I find this analysis utterly unconvincing. Maintaining that economics is a science in the ‘true knowledge’ business, I remain a skeptic of the pretences and aspirations of ‘New Keynesian’ macroeconomics. So far, I cannot really see that it has yielded very much in terms of realist and relevant economic knowledge.
The rather one-sided emphasis of usefulness and its concomitant instrumentalist justification cannot hide that ‘New Keynesians’ cannot give supportive evidence for their considering it fruitful to analyze macroeconomic structures and events as the aggregated result of optimizing representative actors. After having analyzed some of its ontological and epistemological foundations, yours truly cannot but conclude that ‘New Keynesian’ macroeconomics on the whole has not delivered anything else than ‘as if’ unreal and irrelevant models.
Where ‘New Keynesian’ economists think that they can rigorously deduce the aggregate effects of (representative) actors with their reductionist microfoundational methodology, they have to put a blind eye on the emergent properties that characterize all open social systems. The interaction between animal spirits, trust, confidence, institutions etc., cannot be deduced or reduced to a question answerable on the individual level. Macroeconomic structures and phenomena have to be analyzed also on their own terms.
‘New Keynesian’ macromodels describe imaginary worlds using a combination of formal sign systems such as mathematics and ordinary language. The descriptions made are extremely thin and to a large degree disconnected to the specific contexts of the targeted system than one (usually) wants to (partially) represent. This is not by chance. These closed formalistic-mathematical theories and models are constructed for the purpose of being able to deliver purportedly rigorous deductions that may somehow by be exportable to the target system. By analyzing a few causal factors in their ‘macroeconomic laboratories’ they hope they can perform ‘thought experiments’ and observe how these factors operate on their own and without impediments or confounders.
Unfortunately, this is not so. The reason for this is that economic causes never act in a socio-economic vacuum. Causes have to be set in a contextual structure to be able to operate. This structure has to take some form or other, but instead of incorporating structures that are true to the target system, the settings made in these macroeconomic models are rather based on formalistic mathematical tractability. How can we be sure the lessons learned in these theories and models have external validity, when based on highly specific unrealistic assumptions? To have a deductive warrant for things happening in a closed model is no guarantee for them being preserved when applied to the real world.
So, I cannot concur with Krugman – and other sorta-kinda ‘New Keynesians’ – when they try to reduce Keynesian economics to ‘intertemporal maximization modified with sticky prices and a few other deviations.’
The purported strength of New Classical and ‘New Keynesian’ macroeconomics is that they have firm anchorage in preference-based microeconomics, and especially the decisions taken by inter-temporal utility maximizing ‘forward-looking’ individuals.
To some of us, however, this has come at too high a price. The almost quasi-religious insistence that macroeconomics has to have microfoundations – without ever presenting neither ontological nor epistemological justifications for this claim – has put a blind eye to the weakness of the whole enterprise of trying to depict a complex economy based on an all-embracing representative actor equipped with superhuman knowledge, forecasting abilities and forward-looking rational expectations. It is as if – after having swallowed the sour grapes of the Sonnenschein-Mantel-Debreu-theorem – these economists want to resurrect the omniscient Walrasian auctioneer in the form of all-knowing representative actors equipped with rational expectations and assumed to somehow know the true structure of our model of the world.