People see Musk’s $670 billion fortune and imagine turning that into $670 billion worth of services — say, the health care and education mentioned in the wealth tax bill. But Musk is not sitting on hundreds of billions worth of dentists and primary school classrooms. He has a bunch of stock certificates, which are not useful in health care or education. They do not make good bandages or scratch paper.

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There’s a reason that European welfare states are funded with broad revenue raisers such as the value-added tax (a sort of extra-efficient sales tax), not wealth taxes. If it were possible to do it solely by squeezing the rich, the Nordics would have done it long ago. Instead, Denmark has repealed its wealth tax (though there’s a movement to reinstate it), and Norway’s 1 percent wealth tax, which raises about 0.6 percent of GDP, recently caused an exodus of the super-wealthy when it was slightly increased. So instead, they use taxes that make private consumption more expensive, so people buy fewer consumer goods, leaving more to be spent on public services. Because that’s the only way it can work.