Smoking bans, maternal smoking and birth outcomes

• Smoking bans in the workplace have beneficial impacts on birth outcomes.
• In 2004, smoking bans came into effect in restaurants and bars in Norway.
• We find that the ban resulted in fewer pre-term and VLBW infants.
• Mothers are less likely to smoke during pregnancy after the ban.

An important externality of smoking is the harm it might cause to those who do not smoke. This paper examines the impact on birth outcomes of children of female workers who are affected by smoking bans in the workplace. Analyzing a 2004 law change in Norway that extended smoking restrictions to bars and restaurants, we find that children of female workers in restaurants and bars born after the law change saw significantly lower rates of being born below the very low birth weight (VLBW) threshold and were less likely to be born pre-term. We do not find an effect of the ban along other birth outcomes like APGAR scores and birth defects. Using detailed data on smoking status during pregnancy we find that most of the health benefits come from changes in smoking behavior of the mother. Using individual tax data, we find that the law change did not result in changes in earnings or employment opportunities for those affected, suggesting that the effects seen are likely a direct result of changes in smoke exposure in utero.