Sowell’s point in the article is that “trickle down” is not a theory proposed by any actual person. Rather, it is a parody of "supply side economics” - the unexceptionable point that taxation lowers the supply curve and thus reduces economic activity. ”Trickle down economics” is straw man argument.I call supply side economics “unexceptionable,” but of course “liberals” continually take exception to factual statements about reality. Back when Sen. Spector was doing a fairly passable imitation of a Republican, he questioned a witness about his projection of tax revenue as a function of the rate of a particular tax. Spector asked what would be the revenue of that tax if the rate were set at 10%, and the witness gave a number of dollars. Spector asked what the revenue would be if the rate were set at 20%, and the witness doubled the number of dollars. Spector marched all the way up to 100%, and the witness quoted the original number of dollars, time ten. Spector then said, “I give up.”
The correct response would have been for Spector to go beyond 100% at a geometric rate - he should have asked what the witness projected if the rate were 200%, and 400%, and 800%, and 1600% - continuing on until the witness cracked, or everyone in the room started laughing.
I remember that from the debates that went on after the GOP took the congress ~ 1995. They were accused of trickle down when they talked about supply side.