There's one thing we learned for sure this election year: If you want to get people excited, promise to fix the economy.

Every economist and politician worth their salt have different ideas about how we can close the widening gap between the rich and the poor, and there's one tried-and-true solution that lots of them keep coming back to: trickle-down economics. But aside from being named after something that conjures up images of faucets clogged with who-knows-what, what exactly are they? And, more importantly, do they work?

To answer that question, we need to go back a few decades.