Fresh water and salt water macroeconomics
Angry Bear has an excellent synopsis of the state of macroeconomics, and its relationship to the central monetary and fiscal policy debates of today. The post plays on a division of US economists into right-wing “fresh water” economists (epitomized by Chicago) and left-wing “salt water” (Princeton, MIT, Berkeley) that is perhaps a bit simplified (for example the Post-Keynesians at U of Missouri Kansas City and James Galbraith at U of Texas Austin are not close to salt water and do not figure in the post) but makes for a great blog post. An excerpt:
Left and right correspond fairly closely to libertarian vs egalitarian in the US political spectrum, that is, closely to Democratic vs Republican positions on economics (except that there are leading economists well to the left of the Democratic party and well to right of all but the left fringe of the Republican party). It is a fact that, except for general support for free international trade, the range of views of economists is similar to the range of views of congressmen but somewhat broader. This is a wide enough ideological range that the methods of verification used by economists are absolutely unable to force economists on left and right to admit that economists on right and left have a point.
In the field of macroeconomics there is a much deeper division between macroeconomics as practiced at universities closer to the great lakes than to an Ocean (Fresh water economics) and that practiced at universities closer to Oceans (Salt water economics). … It is a little difficult to explain the disagreement to non economists. Frankly, I think this is because non-economists have difficulty believing that any sane person would take ffresh water economics seriously.
Roughly Fresh water economists consider general equilibrium models with complete markets and symmetric information to be decent approximations to reality. Unless they are specifically studying bounded rationality they assume rational expectations, that everyone knows and has always known every conceivable conditional probability. Iâ€™ve only met one economists who claims to believe that people actually do have rational expectations (and I suspect he was joking). However, the fresh water view is that it usually must be assumed that people have rational expectations.
Over near the Great Lakes there is considerable investigation of models in which the market outcome is Pareto efficient, that is, it is asserted that recessions are optimal and that, if they could be prevented, it would be a mistake to prevent them.
Salt water macroeconomics is basically everything else with huge differences between people who attempt to conduct useful empirical research without using formal economic theory and people who note the fundamental theoretical importance of incomplete markets and of asymmetric information and of imperfect competition (as in everything you think you know about general equilibrium theory is known to be false if markets are incomplete or there is asymmetric information or there is imperfect competition â€“ Market outcomes are generically constrained Pareto inefficient which means that everyone can be made better off by regulations imposed by regulators who donâ€™t know anything not known to market participants who also just restrict economic activity and donâ€™t introduce innovations like, say, unemployment insurance).
Leading fresh water macroeconomists include Robert Lucas, Ed Prescott Thomas Sargent, Lars Hansen, John Cochrane, Larry Jones, Robert Barro (mostly), and Kevin Murphy (usually). Leading salt water economists include Paul Samuelson, Edmund Malinvaud, Jacques Dreze, Joseph Stiglitz, Robert Solow, Paul Krugman, Andrei Shliefer, Olivier Blanchard, George Akerlof, Robert Hall, Ben Bernankle, N. Gregory Mankiw, Christina Romer, David Romer and, and Lawrence Summers. Brad DeLong is also a salt water economist and he is very very smart, but last I knew, he was a little too far out there to be really a member of the economists club. I canâ€™t classify Paul Romer.
Notably all of the above have made important contributions to fields other than macroeconomics.
In the US there is a strong correlation between Fresh and Salt and Right and Left. The correlation is not perfect: I understand that Hansen and Sargent are politically left of center. Hall is far right politically, Mankiw is right of center. and I must admit that I have no clue about Bernanke (who I have never actually, you know, seen in the flesh).
An important discrimminant is opinions of John Maynard Keynes. Fresh water macroeconomists generally seem to think that he was not a competent economist. Salt water macroeconomists claim (often implausibly) to be in some way his intellectual followers.