Why not? We tax property every year on it's assessed value. I think it's pretty clear that the wealthy will need to pay more taxes throughout the world to deal with an aging population.
I'm a little tired of billionaires 'buy, borrow, dying' to get around the paltry taxes they're currently subject to. We need a harder tax to dodge.
Why would taxing the wealthy be relevant to an aging population? Do you think that we tax stuff? We just tax money to buy stuff. If a nation produces less stuff, then spending more will just cause prices to go up, but will not result in the production of more stuff to go around.