Let's have a situation where we can start from scratch. Say a post-apocalyptic USA, with new societies trying to rebuild in the rubble. One little city-state is run by a Baron, who got his job in the traditional fashion of imposing order on anarchy. Now he's converted the place to a constitutional monarchy.
The Baron needs tax payments to run his government, but he has a clever scheme to maximize his revenue while minimizing the pain and work in obtaining it. All tax payments are voluntary. That's right, you don't have to pay, and if you do pay you decide how much. Lots of outfits run that way but the baron can do better than announcing "gold circle donors"--he can give real power as a reward to the biggest payers. Your tax payment determines your status for the next year.
The ten biggest taxpayers for the year will be "councilors". They're entitled to regular private meetings with the Baron, attend weekly sessions together to advise him, and have the power to propose new laws. Some councilors are representatives of an organization (for ex., the farmers can all chip in to have "Farmer's League" seat).
The next hundred or so taxpayers are "senators". They can debate and amend proposed laws, and a majority must approve a law for it to go to the Assembly.
Anyone making a substantial contribution--say about 5% of the median annual wage--is an Assemblyman. The Assembly votes on laws, but can only accept or reject them. Approval by the Assembly makes a proposal the law of the land. The government budget must also be approved. This could be a secret ballot. Note that this payment is smaller than 99% of Americans' federal income tax payments today, so the Assembly could be the vast majority of the adult population.
The lowest level of taxpayer is the "pennyman". Any contribution gets this status. Various legal privileges are only available to taxpayers.
Nonpayers are legal residents but can't file court complaints, enforce contracts, etc. without a pennyman acting on their behalf. Anyone receiving welfare or equivalent from the Barony is forced into this status.
For all the levels of taxpayers they're ranked within their group by how much they've paid. So meetings of the council, senate, and assembly always have everyone lined up to go in from highest payment to lowest, and they get to speak in debate, make proposals, and cast votes in that order too.
Twain fans may notice some inspiration from The Curious Republic of Gondour.
The premise of this government is that people are hierarchy climbers, and if you set up a system where they can pay to get to the next level they will. I suspect if this system was tried the government would be getting more money than it really needed.
So would it work?
The first concern is how much power the rich can grab. A Rockefeller will always have more clout than the average citizen. This trick is to make sure they don't dominate it. This system has two checks on the rich. One, they have pay out a large chunk of their money to have one of the top seats. The wealthy can easily bankrupt each other if they keep bidding high for the council seats. Two, the assembly provides a broad-based check on any scheme the council comes up with.
The second is whether this would produce a sufficient and stable revenue flow. It would be prone to bidding wars when someone wants to join the council and low payments when people are content to keep their current positions. This is probably very sensitive to the exact mechanisms. Having a "secret ballot" where payments aren't revealed until after it's too late to pay more for that year would get very different behavior from a system where someone can pay more to move up the ladder any time during the year. More revenue could probably be gained by creating an intermediate status between the pennyman and assemblyman. But the managers of baronial public works projects would always be biting their nails on tax day.
Would it produce good results? I think so. There's two ways for popular opinion to shoot down a bad idea--a no vote in the assembly and withholding of taxes. If suddenly the barony doesn't have the revenue to support a project it's dead. On the flip side anyone can propose a law if he can raise the cash from his own savings or getting donations. He doesn't have to get a permanent seat, he can just sit on the council for one year, propose his law, and go back to his regular life. So there's viable positive and negative feedback mechanisms built in.
Is it fair? No. But that's okay with me. Even in the fairest systems there's a lot of inequality. What happens is that the imbalances get hidden under the façade of equality, until the system cracks. This system brings out the inequalities to where everyone can see them, and makes sure the people getting extra power can't do it for free. So while it's less fair in theory it might actually be more fair in practice.
My biggest concern--and this I'd appreciate help on from my readers--is what do I call it? The best I've come up with so far is "taxpayer-rule" but tracking down the greek for "taxpayer" has been a pain. I think it might be "phorologoumenos". "Phorologoumenocracy" doesn't have that great a ring to it. Anybody have a suggestion?