A law professor whose blog I regularly read seems to have a dislike of economists. Probably stems from a brush with Marx. At http://webapp.utexas.edu/blogs/bleiter/archives/001637.html he questions if Economics is really a science.
The real question ought to be if Economics is really engineering. The Art v. Science debate is really a Religion v. Engineering debate. One of the triumphs of modern medicine is that it is slowly, over time, becoming engineering rather than religion.
The answer to the question seemed obvious to me until my daughter pointed out that my background is in applied economics which is a matter of statistics and observation. Do people living under powerlines have worse health than those who do not and is that a result of the powerlines (yes, to the first question, no to the second -- once you correct for economic differences -- if you live under a powerline you are poorer than those around you -- the difference goes away).
So when I think of Economics, I think of the engineering type applications that work, mostly statistical analysis driven ones, from the days when most analysis of that type was done by economists regardless of the academic field it fell in.
The same is true of the "time and motion" guys -- who were responsible for modern surgical teams. Or the people who did the original critical path analysis.
My favorite theoretical economist was a Yugoslavian who came up with the theory that describes worker managed firms and that works well in looking at law firms, academic departments, small steel plants, and union owned railroads. Definite limits ("who" is a worker with ownership, issues of changing intellectual property, etc.), but nice, clean, useful theory.
To the extent I thought of theory I was looking at observationally and statistically informed micro-economics (i.e. determining what the elasticity of demand for a product is, measuring workflow issues, etc.). Studies that showed that after 35-40 hours of labor a week, you hit diminishing returns.
On the broader scale, on things such as "can one consider Marxist macroeconomics a science?" -- I think that Leiter has a point. I read him, after all, because I don't agree with him -- and so I learn from his posts (and sometimes change my mind). Observational macroeconomics differs a great deal from theoretical. The one says "change this and measure what happens" the other predicts what will happen. Interesting differences.
Though the real question may well be what claim does Economics today have on Applied Statistical Analysis? The days seem to be past when every major economist had resume credits in the space program and other areas of applied mathematics where the economists came in to deal with the math issues and called it applied economics.
I'll have to think. Maybe Leiter has changed my mind again, and maybe not