Except mainstream economics doesn't do that. It makes dramatically unrealistic and sometimes contradictory simplifying assumptions. For details see Steve Keen's Debunking Economics.
Economics concerns subject matter that is far too complex to analyze without making simplifying assumptions. If you want to argue that they make the wrong simplifying assumptions, fine, but what evidence do you have that Computer Scientists are going to do a better job of it just because they have proved the asymptotic bounds of sorting algorithms?
I made no claims about computer scientists. Keen argues that the assumptions made by mainstream economics are in fact terribly wrong.
He also suggests that people outside the field are making better contributions, but I haven't gotten to the part in the book where he argues that in detail.
