Novice Objectivist

I think I have a fairly good grip on economics, at least a basic to intermediate understanding of it, but I don't understand the concept of trickle down economics or supply side economics (Reaganomics?) If anyone could please explain, and give the Objectivist stance on it, I would very much appreciate it.

I am glad I played Bioshock. Not only is in an exceptional game, but I learned about Atlas Shrugged so I was intrigued to read it. Now I am an Objectivist