For someone who's constantly harping about published studies, I assume you have something handy that shows that evasion will be higher under a sales tax than it is under an income tax?How about common sense? Do I really have to provide papers that say sales tax evasion will be higher at ~36% (state + fed) than at 6%?
No, what you need to provide is any sort of resource that says that evasion will be higher under the sales tax than under the income tax. Any tax system has people who evade it -- if you want to claim that the NRST underestimates the impact of evasion, you need to show that net evasion will increase.