We study inequality decomposition by population subgroups. We define properties of a satisfactory decomposition and derive the implied decomposition formulas for well-known inequality indices. We find that the Gini coefficient, the generalized entropy indices, and the Foster-Shneyerov indices all admit satisfactory decomposition formulas derived from a common set of axioms. While our axiomatic approach recovers the established decomposition formulas for the generalized entropy and the Foster-Shneyerov indices, it leads us to a novel decomposition formula for the Gini coefficient. The decomposition of the Gini coefficient is unique given our axioms, easy to compute, and has both a geometric and an arithmetic interpretation.

What happens to earnings upon marriage? Linking administrative and survey data from Germany, we show that there is a marriage earnings gap. Even after accounting for the child penalty, women's earnings drop by 19% after marriage.

We show that the marriage earnings gap results from both the extensive margin (women stop working) and the intensive margin (women work fewer hours), but not from a decrease in hourly wages.

We then study mechanisms behind the observed spousal behavior. Labor supply disincentives from joint taxation can explain about one third of the marriage earnings gap, while we find no effect for labor supply incentives from changes in divorce law. Leveraging variation in norms created by the German separation, we find that gender norms are another important driver behind the marriage earnings gap.

We study top-income persistence in Finland using detailed full-population register data spanning over 20 years. During this period Finland has experienced significant increase in top income shares, particularly within the top percentile. This raises interesting questions: How persistent are the top positions, and do we observe changes in persistence over time? We find that top-income persistence has increased, being more pronounced than the growth of the top income shares. Moreover, our data enable the study of different income concepts such as gross income vs. disposable income and the importance of capital-income components, which allows discussion on the role of our dual income tax system. We provide average income tax rates at the very top of the distribution to illustrate the decrease in income tax progressivity over this period. In addition, we also characterize the evolution of top-income persistence for the self-employed, males and females, and persons of different ages.

This paper provides a household-level perspective on the rise of global saving and wealth since the 1980s. We calculate asset-specific saving flows and capital gains across the wealth distribution for the G3 economies -- the U.S., Europe, and China. In the past four decades, global saving inequality has risen sharply. The share of household saving flows coming from the richest 10% of household increased by 60% while saving of middle-class households has fallen sharply. The most important source for the surge in top-10% saving was the secular rise of global corporate saving whose ultimate owners the rich households are. Housing capital gains have supported wealth growth for middle-class households despite falling saving and rising debt. Without meaningful capital gains in risky assets, the wealth share of the bottom half of the population declined substantially in most G3 economies.