Policy researchers often have to estimate the future effect of imposing a policy in a particular location. There is often historical information on the effects of similar policies in other jurisdictions, but no information on the effects of the policy in the jurisdiction in question, and the...

Policy researchers often have to estimate the future effect of imposing a policy in a particular location. There is often evidence on the effects of similar policies in other jurisdictions, but no information on the effects of the policy in the jurisdiction in question. And the policy may have...