A 2015 report by the International Monetary Fund argues that there is no trickle-down effect as the rich get richer:
If the income share of the top 20 percent (the rich) increases, then GDP growth actually declines over the medium term, suggesting that the benefits do not trickle down. In contrast, an increase in the income share of the bottom 20 percent (the poor) is associated with higher GDP growth.
The trickle-down theory is absolute bullshit. It is a fairytale told by the rich and powerful to the poorer, ill-informed, consumer class on which they rest upon.