Is economics "value-free"?

It's a question that is finally -- finally! -- being raised. It's a question we sometimes raise about science, and people in the rationalist camp (of which I am one) tend to step back from that particular philosophical box of snakes, because the logical next step to saying that science is not value-free is: whose values get to guide and constrain science? The values of the rationalists, or the values of the flat-Earthers?

We now have the same issue on the table: is economics value-free? And if not, then what values -- whose values -- are to guide and constrain economics? Obviously, my philosophical instincts lead me to say "the guiding and constraining principle must be: is the result of this economic decision humane? If so, then proceed. If not, then drop back and re-think." But I have no way to philosophically ground this, which basically means it's merely my opinion, of no more value than any other opinion, including the opinion of the most rabid red-meat capitalist. There's a philosophical challenge here, and I'm not sure how to begin approaching it.