@djc means tests are very costly ways of generating very low quality information even on their own terms of burden measurement. on purely practical grounds, they aren’t worth the trouble. when we impose a progressive income tax, we don’t and don’t have to pretend we are taking holistic circumstance into acount like benefits means tests do. the tax is a blunt imposition, sure maybe based around ethical conjectures like “equivalent sacrifice” but not expected to be just in a fine-grained way. 6/