From kevin
If they get paid in cash, the employer is committing a crime. That's why it happens very rarely. Doesn't happen often enough to worry about.
Here is info on the underground economy.
The underground economy is called the shadow economy, the black market, or the informal economy. While estimates vary, some put the underground economy at 11% to 12% of U.S. gross domestic product (GDP), or roughly $2.25 trillion to $2.5 trillion
A major component of the underground economy are cash-intensive businesses such as liquor and convenience stores, beauty salons, restaurants, taxis, landscaping, construction, domestic work, and small food establishments
One would think kevin with his his background in economics, taxation & cpa would actually know this