Excellent observation. Anyone who works “off the books” is
certainly working and being paid. But, they are not part of the labor force as defined by the Bureau of Labor Statistics.
I've had a lot of plumbing work done recently, my plumber owns his business. We have an arrangement, I pay him in cash, he gives me a nice discount.
I win, the plumber wins, everybody wins, except "the beast". I love starving the beast in any little way that I can.
I urge everybody, who is having any kind of work done to talk to your contractor, it doesn't hurt to ask and you might actually save some money.