It's very easy, really. In the world of economics you're either a "supply-sider" or a "demand-sider."
Supply-siders (AKA "trickle-downers") believe that an economy is best served if government and tax policy powders the behinds of a tiny minority, the rich and corporations (the "suppliers"), with low, low taxes and deregulation, whence they will, out of the benevolence of their hearts (well, more like sheer greed), create jobs and opportunity for all. It's a top/down ideology, just the way the rich always like it: pour benefits and breaks on the top of the hierarchical pyramid, and it will trickle down to everyone else. If you are quite astute, you may notice that this notion is almost identical with that slightly older economic system called "feudalism!"
Alas, supply-siders cannot point to a shred of data to support their position (and they count on nobody actually asking for proof... which both low-information voters and the "liberal" media irresponsibly do not). Though the rich (having a vested interest in its continued application) have tried it over and over and over again for centuries, trickle-down has never actually worked in the history of the world (well, we should say it has never worked for an overall economy; it DOES work quite nicely for the rich).
Trickle-down is a quintessential Conservative Myth! Slashing taxes and deregulation DO NOT spur job creation. Conversely, high taxes on the rich and corporations, and strict regulation DO NOT hinder job creation. Usually, the rich and corporations just pocket their tax cuts, or if they do decide to create any jobs, they'll create them in China and Vietnam (think about the irony in that!). If you're not rich, that drip, drip that you feel? Oh, that "trickle-down" is just the rich pissing on you. There is no science behind supply-side; it's based entirely on mythological faith. Behind this faith is the greedy impulse to support the traditional hierarchy. So, being traditional, hierarchical and mythological makes this economic perspective solidly conservative.
Demand-siders (AKA "Keynesians" after economist John Maynard Keynes) believe that an economy is best served by the exact opposite: skew policies and benefits to bolster the much vaster middle (and poor) classes so that their economic security and prosperity is served so they can afford to buy stuff (that's the "demand" part). Demand must come before supply, not vice-versa. Where there's demand, supply will always follow, but not necessarily the reverse. There can be all the supply in the world, but if no one wants it, or can afford it (no actual demand), it ain't going to sell. Henry Ford had the right idea: "I want to pay my workers enough so they can afford to buy my cars." It's a bottom/up ideology: as the poor and middle class rise, so too will richer folks do fine... perhaps just not as gluttonously as they might prefer.
Demand-siders have a virtual monopoly on actual factual support. Historic statistical data indicate that GDP and job creation tend to go UP following tax INCREASES on the rich and corporations, and strict regulation HELPS NOT HINDERS economic balance, market competition, workers rights and safety, consumer health and well-being, as well as corporate sustainability. Moreover, when capital gains rates go up, wealth disparity goes down; when capital gains rates are decreased, wealth disparity goes up.
So everything the conservatives try to tell us about the wonders of supply-side economics is dead wrong.
The decades when supply-side ideology ruled unchallenged: the 1920s, as well as the 1980s through the 2000s, prove that trickle-down is pure myth. What actually happened is that the rich got exponentially richer, executive pay skyrocketed, the gap between rich and poor exploded, the poor and working class took a whipping, and eventually the economy took a big stumble. Economies are far more stable, and provide a "tide that lifts all boats" when the poor, working class and consumers are favored over the rich and corporate profits. Demand-side is also an infinitely more democratic and egalitarian system. It doesn't pretend to create a completely level economic playing field; there will still be haves and have-nots, but the distance between them will be ever narrower. So, being non-traditional, non-hierarchical, and science-based, you can see that this is a liberal economic notion.
So now that you're an economics expert, which are you: supply-sider or demand-sider?
Bill Maher explains economic theory using the analogies
of baseball and football.