You pay a (progressive) % of your wealth in tax every year, based on your declaration. Financial institutions report your wealth (to some extent), and the deve

You pay a (progressive) % of your wealth in tax every year, based on your declaration. Financial institutions report your wealth (to some extent), and the development of wealth is checked against your income, making tax evasion non-trivial. You could hide the money in a shoebox but you'll lose more in opportunity cost (missed investment gains) than you'll save on tax. The other side of the coin though is that capital gains generally aren't taxed. Mainly, I don't agree that "it is very difficult to tax wealth". It's basically a box "your wealth: <enter number here>" on the tax declaration, with an extra spreadsheet/list to fill out showing what the wealth consists of, plus proof (e.g. bank/stock account statements).