There are some good ideas and some... less good ones in this thread.
Of course, it's all moot anyway as long as people are duping gold, as several have pointed out.
First, to the suggestions to remove/reduce LRC and/or increase insurance: no. Seriously, no. Either would have a severely disproportionate impact on poorer and newer players. Furthermore, reducing LRC cap to 85% or anything less than 100 at this point would seriously anger a lot of people (including me). That ship has sailed.
A tax on services we've been getting and/or players have been providing for years alienates players.
Someone mentioned the city buffs as a good gold sink. The city buffs are a TERRIBLE gold sink, as discussed in many of the governors' threads, because in practice only the governors end up paying them. (Now if each person who USED it had to pay in, then that might be better. But that's not how it is currently working.) They initially tried taxing the city stones, messed up the tax rate so that it taxed the same money every single day until it was gone, then had to get rid of the tax entirely. (Players circumvented it by donating directly to the governors--just as they would circumvent a secure trade tax.) Even now with the tax gone most cities on my shard (Chesapeake) don't maintain the trade agreement. It's a lousy gold sink that encourages only rich players to run for governor, and we can't even tell for certain if anyone is even using it.
Even a buff isn't really an ideal gold sink because it gives a play advantage (however slight).
A good gold sink should be 1. purely aesthetic , 2. temporary, and probably 3. self-renewing unless specifically deactivated. The abyssal skin suggestion for example (or another color, or a special title, or whatever), could cost say 5 million gold per week and auto-renew itself until the player either ran out of money or went back to the npc and deactivated it. A high end city title could cost 1 million gold per week. It needs to be temporary to keep the gold flowing out, but don't make people have to think about having to renew it every so often. A one-time purchase isn't a gold sink. A recurring but optional and non-game-changing expense is.
Personally I don't care for the idea of selling or raffling EM-style items. I think that this will just concentrate the wealth a little differently. I can see it going something like this: instead of 10 people having 100 mil each, now 1 person has a coveted item that 10 people paid 100 mil to try to get... and now that person is going to turn around and sell it for way, way more. Much of the value of gold taken away is put right back in in the form of a super rare item.
Reissuing old EM items will annoy the hell out of the rares collectors. Take that as you will. I think it would be a mistake.
I think there are three things that would best address the economy in UO:
1. As stated above: aesthetic, temporary, auto-renewing gold sinks.
2. Handling money as a number/balance attached to your account. If I'm not mistaken, it's checks that are the most duped thing. Get rid of them, but keep physical gold and make it add to your balance when you put it in the bank instead of making piles and piles of items.
3. (And I'm probably going to get scorched for this.) Open up cross-shard travel to everyone. Make it a quest or something, a slight nuisance perhaps, but something that anyone can do. (Have the shield you get from the Minax artifacts actually work perhaps.) The concentration of everything on Atlantic by a handful of players that have old enough accounts to hop around as they please has left everyone and every other shard in the dust with no way to catch up. Sure you can buy a round-trip for $40 real money in the Origin store, but that is still limited to players with a lot of disposable income. UO needs to be attracting new players and bringing back old ones. New and returning players can't catch up, and therefore can't fully participate in the larger community and economy. Ethereal mounts were such a game changer that the year requirement on the lowest one was reduced, but cross shard travel is MUCH more of a game changer than any magic horse could ever be. Even it up. (And let players trade their old shard shields for other vet rewards so that they won't have wasted all those picks when everyone can jump.)
Another thing that I've thought about but am not really sure about is this: Get rid of the gold for cash sellers. How? Have EA sell gold directly instead in the Origin Store. I won't ever buy it and I find the mechanic problematic at best, but if anyone should be making real money off the game it's the producers, not third party spammers and dupers. We're back to pouring money into the economy again, I know, but I would expect duping to drop so it's a bit of a trade off. This would again benefit players with more disposable income, but it's like that now anyway since they can just go to a third party seller. I have mixed feelings about this idea, but I think there's potential.
Whatever is done, it is essential that the dev team keep in mind that while yes, the economy is unbalanced and some people have mountains of money, many don't. UO is becoming more and more a game that caters to its oldest players--and there's nothing wrong with older players having some special perks!--but new and returning players get left further and further behind. I think that it's important not to hurt poorer and newer/returning players with broad actions aimed at players they may never be financial equals to.