From a high enough vantage point, I'm willing to bet there's a gaping hole that economists can clearly discern, that a calculable quantity of money just "falls into" somehow, and that there's a corresponding class of citizens that are curiously plump, and their feet don't seem to touch the ground, even though they aren't particularly well known, and don't seem to have lucrative careers.

If you took all the public data, and tried to trace all the economic output, as it fell into the pockets of individuals, and tried to follow the spending patterns of individuals, tracing the return path acting as inputs to fund all the legal businesses out there, you probably can quickly notice a gap too large to chalk up to inefficient friction and people hiding money under their mattresses, and it probably looks more like a willful diverting of funds to parts unknown.

By induction and intuition you might hazard a guess about the story behind such phenomena.

well they do file tax returns, but you know what I'm saying :P