>Trickle-down housing policy is a farce. In a highly speculative housing market, increasing the supply does not automatically reduce housing costs. When cities permit more market-rate development, developers build more market-rate housing, because that is what will yield the highest return on investment. Especially when labor productivity lags in the construction sector, the profitability of housing production depends on rising rents. Rents are set not based on the quality of a home but on whatever the market will allow. This is why most “luxury” housing is so ugly and poorly built.

> “Affordability” is an abused concept in development deals and local policy-making. Developers receive public subsidies and tax abatements to build market-rate apartments, sometimes with conditions to set aside “affordable” units. Those conditions rarely create truly affordable housing, because the definitions of “affordable” have more to do with what is affordable for the developer than with what is affordable for a working family. Affordability standards are determined by “area median income,” but the area isn’t a neighborhood; often it’s a county or a metro area, and the incomes aren’t limited to tenants but also include those of property owners.

From the linked Nation article.