There are lots of 'trickle-down' theories. The current one in action in the USA involves printing trillions of dollars and giving it to Wall Street who keep it, companies buy back their stock in record amounts, the Dow goes every higher and the rich get ever richer. The 'trickle-down' never happens, wages stagnate and the middle-class get poorer in real terms. It's crap and will eventually implode.
