We appreciate the opportunity to comment on Dan Shaviro's important piece on how the permanent income hypothesis relates to tax policy. In this piece, Shaviro points out that the arguments in favor of a consumption tax on the one hand, and income averaging on the other, raise significantly related issues. As far as we know, Shaviro is the first person writing in the legal literature to make this connection, and his insightful work is sure to inspire further explorations of the issue...