DP16781 Larger transfers financed with more progressive taxes? On the optimal design of taxes and transfers
We study the optimal joint design of targeted transfers and progressive income taxes. We develop a simple analytical model and demonstrate an optimally negative relation between transfers and income-tax progressivity, due to both efficiency and redistribution concerns. That is, higher transfers should be financed with lower income-tax progressivity. We next quantify the optimal fiscal plan in a rich dynamic model calibrated to the U.S. economy. Transfers should be generous and financed with moderate income-tax progressivity. To redistribute while preserving efficiency, average tax-and-transfer rates should be more progressive than marginal rates. Transfers, even if lump-sum, precisely allow to disentangle average from marginal rates. Targeted transfers further implement non-monotonic marginal rates, but generate only modest additional gains relative to a lump-sum transfer. Quantitatively, the left tail of the income distribution determines the optimal size of the transfer, while the right tail drives the optimal income-tax progressivity.