Snakeeyes ... In Pa., it is estimated about $10 mill per year is "skimmed" from sales tax ... pretty minor. BUT ... to answer your question, The easiest way is to have severe penalties for tax cheats. For retail establishments, for example, computerized cash registers. Plus ... with such a preponderence of credit card and check spending, and very little cash, tracking is not difficult.

As for Texas not having an income tax ... it is a thriving state without one ... think about it ..