I certainly don't agree with everything Rothbard or other Austrians say, and indeed I agree that their greatest errors are driven by ideology. (And despite my general sympathy with Ayn Rand, this goes triple for her and her followers.)<p>That being said, a substantial subset of economics is analogous not, as you say, to a programmer saying<p><pre><code>  the code looks reasonable, so there's no need to test it
</code></pre>
but rather to a mathematician saying<p><pre><code>  the proof is correct, so there's no need to test it
</code></pre>
That is, what is the point of testing the Pythagorean Theorem? Perhaps we should measure a bunch of triangles? Why would you do that, when you have a proof? And yet, many people seem to believe that, e.g., raising the minimum wage might not (<i>ceteris paribus</i>) raise unemployment. They even sometimes collect "evidence" that it doesn't! (See, e.g., the paper by Card &#38; Krueger showing a <i>rise</i> in employment after a minimum-wage hike, which Bill Clinton used as political cover to get Congress raise the minimum wage.)<p>Of course, you'd better be double-sure your proof is right, and I agree that the Austrians sometimes fall down on this point (Rand, triply so). But their <i>approach</i> is right: economics, correctly done, is much closer to mathematics than it is to physics.<p>N.B. I too am a reformed libertarian-Objectivist, and I too know the arguments forward and backward; I could crush a traditional libertarian in a debate, because I know the weaknesses all too well. But it seems that my ultimate parting of ways with them has taken me in the opposite direction from yours. You see, I'm even <i>more</i> radical (or, rather, reactionary) than they are. :-)