Low-income housing subsidies have increasingly shifted towards vouchers that allow recipients to rent in the private market. By 1993, vouchers subsidized as many households as those living in traditional housing projects, although most low-income households did not receive any subsidies. This study investigates whether this policy has raised rents for unsubsidized uni, as many analysts predicted when the program was conceived. The main finding is that low-income households in metropolitan areas with more vouchers have experienced faster rent increases than those where vouchers are less abundant. In the 90 biggest metropolitan areas, vouchers have raised rents by 16 percent on average, a large effect consistent with a low supply elasticity in the low-quality rental housing market. Considered as a transfer program, this result implies that vouchers have caused an $8.2 billion increase in the total rent paid by low-income non-recipients, while only providing a subsidy of $5.8 billion to recipients, resulting in a net loss of $2.4 billion to low-income households.