January 7, 2020

expert reaction to study looking at minimum wage and suicide risk in the United States

Research, published in the Journal of Epidemiology & Community Health, reports a connection between the US minimum wage and suicide risk.

Dr Dean Burnett, Honorary Research Associate, Cardiff University, said:

“The results of this study make logical sense but should be approached with caution and care before any generalisation or extrapolation is made, particularly if it’s to be reported widely. Please be aware of the Samaritans Media Guidelines for reporting suicide.

“The positives of the study are that they suggest a very valuable take-home message that direct economic intervention can be very helpful and beneficial, particularly for those on the ‘lower rungs’ of the societal ladder, so to speak. Suicide and suicidal ideation (genuine contemplation of suicide) are known to be linked to stress, and a source of substantial stress in the modern world is financial.

“Therefore, when you’re on the poverty line, having more money does mean more happiness, less stress. And stress, depression and suicide are strongly intertwined, so you’d logically expect to see fewer suicides if the minimum wage is increased. This would likely be less prominent during times of low unemployment, when people have more options, compared to high unemployment, when ‘any job will do’ is a primary concern.

“Having said all that, there remain countless other factors that affect whether and how someone dies by suicide, and while financial situation remains a very important one, it’s not the only one, so assessing a single variable and deducing suicide rates from single changes is very unlikely to give us a complete picture, as many other aspects are likely to be at work. This is especially important when applying the results here to other countries like the UK. This study is based on US subjects, so there will be cultural and other factors present in one country that won’t apply in others. Japan has a known suicide problem, for instance, and the cultural and economic system there is very different from that of the States, involving a great deal more traditional and cultural component.

“Similarly, the UK, while similar to the states in many ways, has its own cultural, political, and historical factors that a substantially different from the US. Any and all of these could impact on someone’s mental health and likelihood of suicide and making predictions based on date from US citizens is likely to be of limited use, at best.”

Prof David Gunnell, Professor of Epidemiology, Bristol Medical School, University of Bristol, said:

“Periods of economic recession, debt and job loss are all key risk factors for suicide and the incidence of suicide is considerably higher amongst those from poorer socioeconomic groups. Interventions to offset these effects include investment in active labour market programmes and providing adequate income support to those who are out of work, rather than austerity. The USA has some of the highest levels of income inequality in high income countries and so is a good setting to look at the effects of minimum wages on suicide.

“The impact of minimum wage interventions on suicide is unlikely to be ever evaluated in a randomised trial and so evaluations such as reported in this paper are important. This elegant time-series study indicates that, amongst those most vulnerable to suicide, states that increased minimum wages experienced lower rises in suicide at a time of marked year on year rises in suicide in the USA. And so points to another tool in the policy armoury to reduce the income inequalities and offset the impact of recession on suicide.

“The finding of a particular impact at higher unemployment is perhaps surprising, and it will be important to understand the best use of investments to offset the impact of unemployment / debt on suicide risk at times of economic crisis. It might be argued that those who are out of work at a time of economic crisis – if they are receiving inadequate benefits – are made more vulnerable than those in work.”

Dr Stephen Burgess, Group Leader at the MRC Biostatistics Unit, University of Cambridge, said:

“This is a long-term observational study looking at how suicide rates in the United States varied following changes in the minimum wage in different US states. Researchers observed that suicide rates were lower when comparing states in which the minimum wage was raised versus those in which the minimum wage remained the same.

“While it is an observational study and so does not address a causal question directly, the methodology used emulates a randomized trial. By comparing suicide rates just before and just after a rise in the minimum wage in different states, the researchers are able to make comparisons between periods that only differ systematically with respect to the change in minimum wage. This is done by comparing states in which the minimum wage was raised versus states in which the minimum wage remained the same. If changes in suicide rates were similar across all states, then any difference in suicide rates is likely due to external factors. Whereas if suicide rates decreased in states where the minimum wage was raised versus states where the minimum wage remained the same (or decreased to a greater extent), then any difference in suicide rates is likely due to changes in the minimum wage. This is known as the difference-in-differences method. States in which the minimum wage remained the same are analogous to individuals in a trial who are given the placebo, whereas states in which the minimum wage was raised are analogous to individuals in a trial who are given the active treatment.

“The difference-in-differences method is an effective tool for addressing causal questions when it is not possible to conduct a randomized trial. This is a particularly well-performed example of such an analysis. As the investigators are also able to compare college graduates (in whom the effect should not be observed) versus non-graduates (in whom the effect should be observed).”

’Effects of increased minimum wages by unemployment rate on suicide in the USA’ by Kaufman et al. was published in Journal of Epidemiology & Community Health at 23:30 UK time on Tuesday 7^th January 2020. 

DOI: 10.1136/jech-2019-212981

Declared interests

Dr Stephen Burgess: “I have no relevant conflict of interest.”

None others received.