Oh, the authors don't ask that the paper not be cited or quoted without permission?
Ya, I forgot, erosion isn't in the bill therefore it can't happen. Any assumption that human beings will push the envelope when it comes to taxes flies in the face of experience.
To show your 20% you'd need to show that a huge portion of the businesses doing the 85.6% of the sales (after agreeing in writing to collect and forward the tax) were not doing so but in fact were performing criminal acts.
I don't believe that and I frankly doubt that many others do aside from your own little group of a dozen or so income tax loving associates. You've offered no such concrete proof of anything like that - and I doubt you ever will.