Underground or Parallel

Is it an underground economy, black market, or the term I always liked best "parallel market?" A parallel market forms when government tries to control markets. For example, you raise the tax on whiskey, and suddenly people are going to states with lower taxes and bringing the cheaper liquor home to drink, (or even worse buying moonshine). In affect the population creates a parallel flow of liquor into the state that competes with the legal taxed system.

The same thing has happen with labor. The various laws, taxes, and requirements to hire someone is making it more and more attractive to work for cash only, as related in this story form Los Angeles on the cash only work force in the state.

A government, if it is smart, will consider the question of what level of tax will the population bear, before they turn to a parallel market to fulfill their need?