On Mon, 3 Feb 2003, William Dickens wrote:
> That is not what I meant. Of course there is. Its thermodynamics.
> However, to an outsider it looks to impose about as much structure on
> weather modeling as the notion of general equilibrium imposes on
> macro-modeling - - that is that the devil is in the details, big
> models can be less informative than the careful eye of a specialist in

Thermo, by itself, is not an example of a paradigm for meteorology. A
paradigm, in Kuhn's sense, is (a) a theory, (b) empirical observations
that are predicted by the theory, (c) the acceptance of the theory by most
practitioners in the field, who use the theory to resolve new cases. The
empirical results are the blueprint for future research. It seems that
thermo is simply a rule for constructing paradigms within meteorology -
i.e., any paradigm must not contradict thermo. Kind of like any macro
theory must have correct microfoundations. 

Of course, I can't say if your depiction of meteorology is accurate, but
we can ask if macro satisfies (a)-(c). 

Is there currently a widely accpeted theory whose legitimacy rests on the
successful prediction of a specific business cycle? 

Is that theory the blueprint for most work in macro?

Alex says yes, there is a widely accepted theory, and "Brookings" Bill
Dickens says no. But neither person has provided the "model achievement" -
the business cycle or other economic phenomena whose successful prediction
by the theory legitimizes is position as a dominant macro-economic theory.

Is there any such empirical example? The stagflation episode overturned
the old theory, but is there a new theory that uses stagflation as its
main example?

> >Some core parts of physics deal with complexity -  how about statistical
> >mechanics? Is there a macro counterpart to statistical mechanics?
> 
> Not sure what you mean by this, but I suspect that is exactly what the
> stochastic mechanics of the typical general equilibrium model is
> about.

Adressing the idea that complexity undermines attempts at econ's Kuhnian
development as a science, I was simply pointing out that some parts of
physics deal with "complex systems" but still have Kuhn style
paradigms. Statistical mechanics is one such example: theory behavior
gases - a complex system - has dominant theories. The theory of phase
transitions might be another example.

> But you miss my point. I'm arguing that the phenomena
> physicists study at the core of the discipline are amenable to
> sufficiently exact theory and exact measurement that you can have
> decisive paradigm shifts driven by anomalous research results.
> Economic theory is not as precise so measurement can't provide the
> sort of strong evidence that one sees in core physics.

Fair enough. Measurement definitely would preclude anamoly driven change
because adherent of a theory could always claim that measurements do not
capture the real story.

[clipped a long discussion on recent history of macro]

> economics. If you mean neo or new-Keynesians then the differences
> between them and new-classicals (the heirs to 60s monetarism) is minor
> compared to their differences with Austrians or post-Keynesians. But
> so what? Post Keynesians and modern Austrians play absolutely no roll
> William T. Dickens

The point of the thread - at least my goal - was to assess Kuhn's
model. If it is indeed the case that general equilibria theory is the
paradigm for macro,  then schools of economics that reject gen equi. would
small time players in the field. So  gen eq succeeds as a paradigm because
Austrians and post-Keynesians are marginal. 

However, to satisfy Kuhn's definition of paradigm, there has to also be a
"classic example" and future research has to be derived from the example.
I don't know macro well enough to judge, but so far no one has given me an
example such an empirical prediction. Altough we know stagflation led to
the revision of a given research tradition.

Fabio


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