I support the concept of taxing wealth, but I've yet to find a good way to implement it. The two biggest issues are that wealth is easily moved to places where it can't be taxed, and those making the tax decisions are easily influenced by those with wealth.

Wealth moves in lots of ways. Yes, as has been pointed out, we over value stock assets. When you own a significant percentage of a company, you can't just sell that ownership at the last trading price (the stock price would quickly crash). Wealth is also moved between national borders, allowing the wealthy to shop for the lowest tax location to stash their funds. Property can't be moved, but it can be financed with debt, making it taxed at effectively 0%. And the other side of that debt may just be an overseas shell company. There will be entire industries formed around avoiding a wealth tax, funded by the wealthy.

But probably the most capital efficient way to avoid the wealth tax is to buy politicians, influence the elections, and invest in lobbyist, which the wealthy do in the US to avoid taxes. Until money is removed from politics, I'm not holding out any hope that we'll find a way to tax the wealthy.