But wealth taxes, like the window tax, don’t work . First, it sounds small, but a 2% tax on wealth is the equivalent of a 50% capital gains tax, assuming a 4% return on assets, and wealth taxes need to be paid even if someone’s investments lose money. Second, by removing so much capital from markets and reallocating it to the government, a wealth tax could lower growth and distort incentives.The primary problem with a wealth tax, however, is that it is just very hard to implement. It gives the rich an incentive to either move somewhere with lower taxes or put their wealth in hard-to-value assets, such as art or private equity.
I hadn't thought of art/equity as tax avoidance before but it makes sense.