Atkinson, Piketty, and Saez (2011) survey an important new literature using income taxbased data to measure the share of income held by top income groups. But changes in tax legislation that expand the tax base to include income sources (e.g. capital gains, dividends, etc.) disproportionately...

Survey under-coverage of top incomes leads to bias in survey-based estimates of overall income inequality. Using income tax record data in combination with survey data is a potential approach to address the problem; we consider here the UK's pioneering 'SPI adjustment' method that implements...