Greg Sargent reports the positive news that ÜberCongress Dems are seriously mulling Jeff Merkley’s (D-OR) proposal to have the CBO score the impact of its proposals on employment as well as the deficit.

Great, but – why don’t they always do that? Shouldn’t they logically always have to do this? If someone proposed to say, immediately kibosh unemployment insurance, the nominal impact on the deficit would be to lower it. But assuming (as one might) that that would have a pretty deleterious effect on employment, that would then mean that you would be bringing in less revenue, right? Which would mean that the original assessment of the budgetary impact would be wrong unless you adjusted for the effect on employment.

So why is this an issue? Or rather, why isn’t this always an issue?