None of this fountain/waterfall nonsense, not until Witis shows his cheetah face again
Fountains are better than waterfalls because you can fit more sharks in them.

Baloney. I can hold onto just as much crap as any rich person. My garage is proof of this.
Fair enough but that's not really what I meant. I wasn't referring to physical "stuff" but rather wealth. The rich are better placed to make investments that are likely to grow, they can hire lawyers to protect their assets, they can hire accountants to help them pay less tax. I don't mean to imply that they're in some way cheating or evil, they're just following the same imperatives which we all have, they're just better placed to follow them. Neither are they like Scrooge McDuck with a big room full of gold coins they swim in, they do spend money and that does feed into various bits of the economy (both global and domestic). But it's a natural human instinct to aquire wealth and to pass that on to subsequent generations.

There's plenty of historical evidence for wealth tricking upwards. It's only fairly recently (the last century) when we started using taxation to try and redress the balance. Prior to that the poor would usually pay more in tax than the rich, who often paid nothing at all (mainly because it was the rich who set the rules) and the effect was massive disparity in income and almost no middle class.

It's worth re-stating, though, that I think the effects in either direction are minor and slow. If you want to get money to a particular part of your economy, that's where you should put it. Putting it somewhere else and arguing that it will "trickle" to where you want it to be seems a bit daft to me.