Objectives: Because household smoking levels and adoption of domestic smoking rules may be endogenously related, we estimated a nonrecursive regression model to determine the simultaneous relationship between home smoking restrictions and household smoking.
Methods: We used data from a May-June 2012 survey of Philadelphia, Pennsylvania, households with smokers (n = 456) to determine the simultaneous association between smoking levels in the home and the presence of home restrictions on smoking.
Results: We found that home smoking rules predicted smoking in the home but smoking in the home had no effect on home smoking restrictions.
Conclusions: Absent in-home randomized experiments, a quasi-experimental causal inference suggesting that home smoking rules result in lower home smoking levels may be plausible.