I thought this part was really interesting: 

-Working for cash, aka the under-the-table economy

This one is very tough to measure, too. A study by the Federal Reserve of St. Louis estimates that the average size of the “informal economy” in developed countries is 13% of GDP. Honestly, that could be off by many percentage points, but just to give you a ballpark, GDP in the U.S. this year is about $22 trillion. So 13% of that is $2.86 trillion. As it turns out, $2 trillion-plus, is a number that has been thrown around quite a bit (here and here for instance) when it comes to estimating the size of the cash economy in the U.S. Even if half that money is paid out to women, that still leaves, say, $1 trillion dollars being made by men in this country off the books. That’s a big chunk of change. Are more people than ever working for cash these days? Again, another question that’s impossible to answer. I would bet it’s not fewer. For example, my electrician Luis just told me he can’t get anyone to work for him anymore — they all want to get paid in cash.

It's also usually men who are usually on about cryptocurrency.