Massachusetts is weighing a ballot initiative that would cap rent increases at the rate of inflation with no vacancy decontrol, one of the most stringent rent control regimes proposed in the country. Cato’s Ryan Bourne and Jeff Miron walk through why economists are nearly unanimous in opposing rent control: it shrinks rental supply, degrades housing quality, and tends to benefit longer-term, higher-income tenants rather than the low-income renters it claims to help. As Cambridge’s own history shows, the policy doesn’t just fail to solve the affordability problem; it actively makes it worse.