Health consequences of easier access to alcohol: New Zealand evidence

We evaluate the health effects of a reduction in New Zealand's minimum legal purchase age for alcohol. Difference-in-differences (DD) estimates show a substantial increase in alcohol-related hospitalizations among those newly eligible to purchase liquor, around 24.6% (s.e. = 5.5%) for males and 22% (s.e. = 8.1%) for females. There is less evidence of an effect among ineligible younger cohorts. There is little evidence of alcohol either complementing or substituting for drugs. We do not find evidence that earlier access to alcohol is associated with learning from experience. We also present regression discontinuity estimates, but emphasize DD estimates since in a simulation of a rational addiction model DD estimates are closer than regression discontinuity estimates to the policy's true effect.