Trickle-Down Economics
What American author and journalist William Blum says here seems correct.
The reason trickle-down economics doesn’t work is that making rich people richer does not provide them with any incentive to hire additional people.
I had over 100 employees at one point in the 1990s, and the only thing that made me even consider hiring one more was that I knew that my delivery unit would be incapable of serving our clients adequately if I didn’t.
I’m not a miser, but in the absence of that pressure, I would have kept my money in my pocket.