The Marriage Tax Penalty

This book is an overview of issues associated with the marriage penalty. The first section explains how the marriage penalty (and the marriage bonus) arises and why it is not possible to achieve simultaneously the goals of marriage neutrality and horizontal equity across families in a progressive tax system. The second section discusses the size of the marriage penalty, the bonus and importantly, the notion that the marriage penalty is not a precisely defined measure. The next section outlines the issues of equity, efficiency and simplicity that are part of the frame work for evaluating policy and the final section discusses various legislative proposals in light of these objectives. The book also estimates the effects of current tax policies on families of different types and sizes and analyses proposals to address the marriage penalty and the child tax credit. It contains a history of the development of tax provisions affecting the family.

The tax regimes applied to couples in many countries including the US, France, and Germany imply either a marriage penalty or a marriage bonus. We study how they affect the decision to get married by considering two potential spouses who play a marriage proposal game. At the end of the game they may get married, live together without formal marriage, or split up. In this signaling game, proposing (or getting married) is costly but can indicate strong love. The striking property we obtain is that a marriage bonus may actually reduce the probability that a couple gets married. If the bonus is sufficiently large, the signaling mechanism breaks down, and only a pooling equilibrium in which fewer couples get married remains. Similarly, a marriage penalty may increase the marriage probability. Specifically, the penalty may lead to a separating equilibrium with efficiency enhancing information transmission, which was otherwise not possible. Our results also imply that marriage decisions in the laissez-faire are not necessarily privately optimal. In some cases a bonus or a penalty may effectively make the marriage decision more efficient; it may increase the number of efficient marriages that otherwise may not be concluded.