There is no shortage of reasons to doubt the wisdom of a national wealth tax. Annually valuing the paintings, boats, planes, diamonds and other assets that rich people tend to accumulate would not be an easy task, either for their owners or government auditors. Innovation and entrepreneurship would suffer, both from the reduced pool of capital available to startups and from the lower expected return on investment. And while family businesses often look prosperous in their annual reports, many would be hard pressed to raise extra cash for a yearly wealth tax.

But perhaps the best reason to be skeptical of a wealth tax is that it has already been tried multiple times in Europe and clearly found wanting. In 1990, as many as twelve OECD countries had a net worth levy on their books, but just a decade later only Norway, Spain and Switzerland had kept the legislation. And of those three, only Switzerland had managed to make any money from it. ...

The European countries which experimented with a wealth tax in our own time were able to pull back from it because they were small enough to have lost too many affluent taxpayers to neighboring nations. But history’s prognosis for the consequences of a US wealth tax is not nearly as rosy.