Horizontal equity of taxation: citizen beliefs and policy preferences

Horizontal inequity occurs when employees and self-employed with the same income end up with different effective tax burdens, due to the difficulty of enforcing taxes on self-employed. Based on detailed micro-tax simulations models integrated with household surveys in 29 developing countries, we show that tax systems incur large horizontal inequities in practice and that reforms which improve vertical equity worsen horizontal equity by a comparable amount. An in-person survey in Pakistan and online surveys across multiple countries reveal widespread concern about horizontal equity. Randomized information treatments heighten this concern but do not shift tax preferences toward addressing horizontal inequity.