The Penn Wharton researchers also say that Warren’s wealth tax plan will not raise the roughly $3.75 trillion in revenue over a decade that the candidate maintains it would.

Instead, it is expected to bring in between $2.3 trillion and $2.7 trillion. That’s largely because the rich will try to reduce their exposure to the tax in a variety of legal and illegal ways, including setting up charitable foundations, moving the money offshore and putting a lower value on their assets.

The report does take into account various anti-evasion measures, but without more details of what Warren would propose, researchers could not evaluate their effectiveness.

The campaign responded that it developed detailed anti-evasion efforts to address problems encountered in other countries.