Federal Incentives for Zoning Reform
Grade B — Moderate EvidenceFederal grants conditioned on local upzoning, elimination of single-family-only zoning.
Rank #6 of 12 policies
📊 Bradford Hill Criteria Scores
💥 Impact Breakdown
📋 Policy Details
Tokyo has no housing crisis because they allow building. Minneapolis eliminated single-family zoning: rents stabilized. Oregon statewide upzoning reduced housing cost growth. Restrictive zoning costs the US economy $1.6T/yr in lost GDP.
🔬 Evidence Assessment: Bradford Hill Criteria
The Bradford Hill criteria are nine principles used to establish evidence of a causal relationship between a policy intervention and its outcomes. Originally developed for epidemiology (1965), they provide a structured framework for evaluating whether an observed association is truly causal. Each criterion is scored from 0 to 1.
How large is the association between the policy and the outcome? Larger effect sizes increase confidence in causation.
Has the relationship been observed across different populations, settings, and times? Replication strengthens causal claims.
Does the policy change precede the outcome change? Temporal ordering is a necessary condition for causation.
Is there a dose-response relationship? More of the policy leads to more of the effect? Gradients support causation.
Is there evidence from randomized controlled trials or natural experiments? Experimental evidence is the gold standard.
Is there a plausible mechanism explaining how the policy causes the outcome? Mechanistic understanding increases confidence.
Does the causal interpretation fit with existing knowledge? The relationship should not contradict established facts.
Are there analogous policies that have produced similar effects? Similar interventions with known effects support the claim.
Is the effect specific to this policy rather than a general phenomenon? Specific associations are more likely causal.
How is the Causal Confidence Score calculated?
The Causal Confidence Score (CCS) of 68% is a weighted average of the nine Bradford Hill criteria. Experiment and temporality receive higher weights since they provide the strongest evidence for causation. The CCS is then combined with the estimated effect magnitude to produce the Policy Impact Score (PIS) of 56%.
See the Optimal Policy Generator paper for full methodology.
Analysis: · Optomitron OPG