A policy that's supposed to create more affordable housing often backfires, leaving cities with higher home prices and rents. There's a way to fix that.

• Inclusionary zoning policies can backfire, leading to fewer homes and higher housing costs.
• A new study suggests ways to optimize inclusionary zoning for affordable housing.
• But direct housing subsidies, like vouchers, can be more effective and flexible.

A key policy designed to create affordable housing for low-income people has long been scrutinized for being generally ineffective.

Inclusionary zoning, which originated in the 1970s, is designed to boost the production of affordable housing by requiring or incentivizing developers to set aside a certain share of below-market-rate units when building new apartments or homes.