I think economics should be a descriptive science, not a set of arguments for one particular political system. Markets have certain consequences that we may or may not want, and so do certain types of government interventions. Planned economies don't tend to have very many desirable consequences, as far as I can tell, but that's not how most economic policies work anyway.

I'm not a good enough economist to give an intellectually honest account of what would happen in an anarcho-capitalist system, but I doubt from a historical and anthropological standpoint that anarcho-capitalism is likely to ever happen anyway.