With a low flat tax, the incentive for a black market decreases. Everyone will want to produce and pay their taxes. There wouldn't be any of this avoidance.
Not everyone produces, yet everyone consumes. Fair Tax is a consumption tax, capturing EVERYONE into the tax code.
And it gives EVERYONE a bogus "prebate", including those who won't find work. Pretty soon you're going to have a bunch of people refusing to work and living off of their prebates, and tax revenues will decline.
I'd like to see who can live off the pre-bate and refuse to work. $196/month? That won't cover rent...ANYWHERE.