You're asking how people would feel if they were forced into high-tax and low-tax test groups.. But suppose people are given a choice opt-in to a tax lottery system, such that instead of paying a fixed rate the taxpayer would have a random chance of paying either a higher or lower rate.
As initially reprehensible as this sounds to me, the government could make quite a bit of money by taking clues from the gaming industry. Gamification of the tax system?