I don't think it's very difficult at all. We already have an elaborate system to measure and tax wealth with our system of property taxes on real estate. That's

I don't think it's very difficult at all. We already have an elaborate system to measure and tax wealth with our system of property taxes on real estate. That's already in place. It would be trivially easy as well to track and tax the wealth of people hold public equities. Those two things there are an enormous bulk (majority?) of wealth. It only gets a bit more complicated with privately held equities this I will grant. If you start to get into the nitty gritty of assessing assets like ming vases and such it gets complex as well and likely diminishing returns, but at this point, with this stuff, you might as well not even bother because few are going to hold their wealth in ming vases.