In the US, suicide is a major public health problem, with double-digit rates of preventable deaths among adults under 45. And, alarmingly, the numbers have been rising in recent decades. But recognizing this as a source of preventable deaths is quite different from actually figuring out how to prevent them.
One of the challenges is that several factors contribute to the depression and stress associated with suicide, so it’s challenging to determine which ones play the most important role and how to tackle them. However, a number of studies have shown that financial stressors are an important contributor. And a few recent studies have suggested that a public policy that can reduce financial stress does seem to have an impact on suicide rates: the minimum wage.
Now, researchers at Emory University have followed that up with a comprehensive look at the correlations between suicide rates and minimum wage laws. They find that the correlation does hold, but only among people with a high school education or lower, and only during times of high unemployment.
National data plan
The minimum wage may seem strange to look at, but it’s one of those situations where we already have a surprising amount of data pointing to it. Suicide is often associated with financial stressors, such as job loss or mounting debt. Suicide and depression are most common among people with lower incomes and lower educational attainment, both of which mean that the individuals often work at or near minimum wage. So it’s not hard to see why researchers might be interested in taking a closer look.
Taking a look also involves collecting data sets that are actually fairly well tracked (unlike many other social factors). Minimum wage laws are structured quite simply: There is a federal minimum wage, which states can exceed but not undercut. Individual state rules are a matter of legislation that can be easily followed. And, conveniently, a number of states changed the minimum wage during the period the researchers studied, providing a before-and-after experiment. Adjusting the minimum wage for inflation is also easy to do with publicly available figures.
The US maintains a National Vital Statistics System, which provides data derived from every death certificate, including the cause of death and the deceased’s educational achievement. States also keep useful data such as share of GDP, unemployment rate and various forms of government aid. Collectively, these were analyzed to determine whether and how minimum wage rules correlated with suicide rates.
The specific analysis performed was a difference in differences analysis. This used college graduates as the control group, as they are much less likely to commit suicide or work at or near minimum wage. Their response to changes in minimum wage laws (which should be minimal) was compared to those of those with a high school education or less; all this was tracked from month to month.
As expected, changes in the minimum wage had no effect on the suicide rate among the highly educated. But the less educated were more sensitive to it. For those with a high school diploma or lower, “We estimate that the suicide rate among adults ages 18-64 is reduced by six percent for every dollar increase in the minimum wage.” By controlling for some of the additional state-level economic factors that the authors tracked, the effect dropped to 3.5 percent, although it was still there.
But it wasn’t just a matter of who was affected, there was also a matter of when. If unemployment was below four percent, changing the minimum wage had no significant effect. But when it was above six percent, higher minimum wages were found to have a much stronger impact on suicide rates. The biggest impact came when unemployment was over seven percent and the minimum wage was $1.75 or more above the federal minimum.
The researchers also looked specifically at the 2008 economic collapse and estimate that a $1 minimum wage increase could have prevented more than 13,000 suicides if previous trends had continued over this time period.
The researchers acknowledge that there are almost certainly additional complications. Demographics such as women, blacks and Hispanics are more likely to earn at or near the minimum wage. Yet suicide rates for these groups vary widely. And, as mentioned above, a number of other economic factors can modulate the effects of the minimum wage.
Still, the result is consistent with the idea that things that reduce economic stress at times when that stress is elevated may reduce some of the factors — stress and depression — that increase suicide risk. And that is probably more useful information in the end, as the minimum wage is not a policy tool that can be easily deployed in times of economic crisis, as realistically it cannot be repealed once the crisis is over. But, armed with this information, researchers could potentially identify alternative policies that deliver equivalent reductions in economic distress.
Journal of Epidemiology & Community Health2020. DOI: 10.1136/jech-2019-212981 (About DOIs).