One of the embarrassing dirty little secrets of economics is that there is no such thing as economic theory properly so-called. There is simply no set of foundational bedrock principles on which one can base calculations that illuminate situations in the real world. Biologists know that every cell runs off instructions for protein synthesis encoded in its DNA. Chemists start with what the Heisenberg and Pauli principles plus the three-dimensionality of space tell us about stable electron configurations. Physicists start with the four fundamental forces of nature. Economists have none of that. The "economic principles" underpinning their theories are a fraud--not bedrock truths but mere knobs twiddled and tunes so that th right conclusions come out of the analysis.I'll keep hammering these fools to pieces as I come across them. In the meantime, Rizzo does a good job of reducing the intellectual structure of DeLong down to size:
What are the "right" conclusions? It depends on what type of economist you are, for three [sic] are two types. One type chooses, for non-economic and non-scientific reasons, a political stance and a political set of allies, and twiddles and tunes their assumptions until they come out with conclusions that please their allies and their stance. The other type takes the carcass of history, throws it into the pot, turns up the heat, and boils it down, hoping that the bones and the skeleton that emerge will teach lessons and suggest principles that will be useful to voters, bureaucrats, and politicians as they try to guide our civilization as it slouches toward utopia. (You will not be surprised to learn that I think that only this second kind of economist has any use at all.)
What are the principles according to which data are constructed? What are the factors or standards by which some events are chosen as relevant? These are theoretical issues. In an important sense the carcass, the boiling, and the pot itself are creations of theory.
Since the second type of economist is impossible, the reality is that the two types of economists to which DeLong refers are really the same: ideologues masquerading as scientists. In DeLong’s world: Either you consciously and deliberately distort science for extra-scientific purposes or you unconsciously distort it for non-scientific purposes. Either you are an explicit ideologue or an implicit ideologue.
The implicit ideologue deceives himself as well as others. He acquires his ideology as a result of prejudices, psychological needs, fantasies and so forth. Although the deliberate deceiver is morally reprehensible, the implicit ideologue is pathetic and perhaps more dangerous because he really believes he is objective.
Fortunately, science is possible. It need not be either explicitly or implicitly disguised ideology.
We have learned more about how Brad DeLong practices economics from the above quotation than we have about the discipline of economics.