An income inequality measure satisfies the Pigou-Dalton transfer principle if progressive transfers decrease income inequality. When transfers cause transaction costs, one can trace out the maximum leakage such that the transfer pays at the margin. An income inequality measure is leaky-bucket...

Leaky-bucket transactions can be regarded as income transfers allowing for transaction costs. In its most rudimentary form, leaky-bucket transactions trace out the maximum “leakage” of transaction costs before income inequality is exacerbated, or—alternatively—before a welfare loss is...

The conventional approach to comparing tax progression (using local measures, global measures or dominance relations for first moment distribution functions) often lacks applicability to the real world: local measures of tax progression have the disadvantage of ignoring the income distribution...