Of course they hide their money -- no one but a fool volunteers to be taxed if there's another viable option.
There will be evasion and cheating -- this is a fact of human nature independent of taxation system. But it certainly will be no easier to cheat under the NRST -- with only 20 million tax collection points (instead of 200 million individual and corporate filers) and the fact that 80% of the sales come from only 20% of retail businesses, I find it extremely unlikely that sales tax cheating will exceed that of the income tax.
Do you think that Sears, Wal-Mart, or McDonald's will risk tax evasion charges to help you save a few bucks?
You are fooling yourself if you think behavior will remain the same under the so-called "Fair Tax". While the number of "collection points" will remain the same, there will be a whole lot of new retail sales outside of those "collection points" under the NRST. Wal-Mart will sell a whole lot less tires under the NRST because people will evade the tax by buying tires outside of the current legitimate "collection points".