• suicide
• health policy
• unemployment

Kaufman and colleagues have considered the relationship between minimum wage and suicide mortality in the USA.¹ Overall, they found that a dollar increase in the minimum wage was related to a meaningful 3.4% decrease in suicide mortality for those of lower educational attainment. Interestingly, this is the third paper in recent months to address the question of how minimum wage affects suicide. Across these papers, there is a remarkable overall consistency of findings, and important subissues are highlighted in each individual paper.

The first of these papers, by Gertner and colleagues, found a 1.9% reduction in suicide associated with a dollar increase in the minimum wage across the total population.² However, this research was unable to delve into the subgroup effects that would have allowed for a difference in differences approach, or placebo tests, due to their data source. First, Dow and colleagues,³ and then Kaufman and colleagues¹ built on this initial finding with analyses of data that facilitated examination of subgroups. Both of these papers considered the group with a high school education or less as the treated group, that is, the group that would be impacted by a change in minimum wage. The examination of a lower education group as treated is supported by research that finds those who have completed high school or less education make up most of the low-wage employees, and most benefit from increases in minimum wage.⁴ Dow et al uses a difference in differences approach that compares across states with different minimum wages within the same year and examines the more educated group (that would not be expected to respond to changes in the minimum wage) as a placebo test.³ Kaufman e t al similarly leverages a difference in differences approach, but directly compares the lower education treated group to a more educated group as the control.¹ In both of these analyses that examine effects in the lower education group, the minimum wage effects are stronger than those observed by Gertner et al in the total population (as would be expected) and notably similar to each other, in the range of a 3%–4% reduction in suicide for a dollar increase in the minimum wage. The difference in magnitudes of association between the total population and those of lower education is consistent with the population distribution of education; about 40% of the US population is in the lower education group that would be most strongly affected by the minimum wage.⁵ Taken together, despite variations in time frames and analytical approaches, these papers collectively suggest a consistent and meaningful impact of the minimum wage on suicide mortality.

A novel contribution of this work by Kaufman et al concerns modification of the relationship between the minimum wage and suicide by the unemployment rate.¹ Research generally supports that minimum wage increases do not adversely affect employment,^{4 6} and this work highlights that minimum wage may be particularly important as a protective factor under conditions of higher unemployment. There are certainly plausible mechanisms that could explain this finding. For example, when unemployment is higher, for any employed worker, the wage earned may become more critical, given that others in the family would be more likely to experience unemployment.

Additional insight is added by Dow et al, who examines differential impacts of the minimum wage on suicide by gender and race/ethnicity.³ The effect on women is substantially stronger than that among men, consistent with work that finds women’s earnings are increased more strongly by minimum wage changes because they are over-represented at the bottom of the wage distribution relative to men.⁴ Subgroups that combine race/ethnicity and gender reveal intriguing patterns suggesting the strongest protective effects among racial/ethnic minority men and among white women.³ Together with work on how earnings are affected by the minimum wage within various subgroups of age, race/ethnicity, gender and family structure,⁴ these findings suggest the importance of detailed work with family-level data on the impacts that are felt by minimum wage changes, and how and why they differ for demographic subgroups.

Overall, these papers make an important contribution to support that minimum wage policy can improve population health, and may reduce not only economic inequality but also health inequality. The findings are generally consistent with a broader body of work that suggests the importance of economic conditions and policies to suicide in the USA,^7–9 as well as with work that suggests minimum wage increases improve well-being.¹⁰ It is notable that among the economic conditions and policies considered in past research, the minimum wage is one actionable economic policy lever. Identification of approaches to reduce suicide is particularly important, given recent dramatic increases in suicide in the USA.¹¹ It would be illuminating for future work to build on these findings by considering individual-level and family-level data that would facilitate examination of mechanisms of effect behind minimum wage impacts, as well as uncovering more details of which racial/ethnic and gender subgroups are impacted more substantially by the minimum wage and the underlying reasons for these differential impacts.