In my lastcolumn, I explained how Senator Elizabeth Warren’s wealth tax violates well-established constitutional limits on income and transfer taxes. Ever since the Sixteenth Amendment legalized the income tax, all taxes on income have been based on some fraction of the amount earned within a given year. And all taxes on capital are imposed only once, namely at their transfer during life or upon death. In contrast, the Warren wealth tax would be imposed annually on all forms of wealth at rates that start at 2 percent for households whose net worth is between $50 million and $1 billion, and 3 percent for households who hold amounts of wealth in excess of $1 billion. The tax applies in both rich and lean years, whether a person makes or loses money.

To defend this dubious scheme on economic grounds, Warren, now a presidential aspirant, relies on a letter prepared by two prominent economists from Berkeley, Emmanuel Saez and Gabriel Zucman, both experts on the economics of inequality. Indeed, it is just there that the problems begin, for any fixation with equality or, as Saez and Zucman call it, equitable growth, rests on shaky premises.