Causal Spousal Health Spillover Effects and Implications for Program Evaluation

Area of Science:

• Health Economics
• Behavioral Economics
• Public Health

Background:

• Cost-effectiveness analysis (CEA) often overlooks social spillovers, potentially leading to biased evaluations of health interventions.
• Underestimating the comprehensive effects of interventions due to ignored spillovers can result in suboptimal resource allocation.
• Social ties, particularly within marriage, can influence individual health behaviors, a factor rarely incorporated into standard CEA.

Purpose of the Study:

• To discuss the implications of social spillovers for program evaluation in health economics.
• To provide the first empirical evidence of causal spillovers in health behaviors between spouses.
• To re-evaluate the cost-effectiveness of interventions considering these spillovers.

Main Methods:

• Leveraging experimental data from the Lung Health Study (smoking cessation) and the COMBINE Study (alcohol reduction).
• Employing methods to identify and quantify causal spillovers of health behaviors between married participants.
• Recalculating incremental cost-effectiveness ratios (ICERs) incorporating observed spillovers.

Main Results:

• Significant reductions in spousal substance use (smoking and drinking) were observed when one partner received treatment, particularly those involving a therapy component.
• These spillovers demonstrate a measurable impact of an individual's health intervention on their spouse's behavior.
• The inclusion of social spillovers reduced the incremental cost-effectiveness ratios of certain interventions by 12 to 18 percent.

Conclusions:

• Social spillovers between spouses are a significant factor in health behavior change.
• Current cost-effectiveness analyses may underestimate the true benefits of health interventions by not accounting for these spillovers.
• Incorporating social spillovers into CEA can lead to more accurate resource allocation and improved public health program efficiency.