A common critique of most measures of income inequality, which are based on a single year's income, is that they fail to take account of income mobility. If income fluctuations are large, and individuals can smooth consumption, then high inequality and high mobility may be no worse than low...

Do income taxes levied at a state or regional level affect the after-tax distribution of income? Or do workers merely move between regions, causing pre-tax wages to adjust? This question is relevant both in across states in the United States, and across countries within the European Union. Using...