The question I was raising is whether economists have an answer for everything because their mathematical method lets them make stuff up whenever they like.

Sure, scientists can generate many models to see which one fits the data. But you've got to test the models so you're not just giving yourself a million outs (i.e. an arbitrary, ad hoc answer for everything). And it's not as easy to test economic models as it is to test the ones from the hard sciences.

That's the problem. And that's why the charge of unfalsifiability is arguable in this case of economics, but not so much in the natural sciences.