Published by Paul Leigh
University of California Davis School of Medicine and Center for Poverty Research
These findings are described in the article entitled Minimum wages and public health: A literature review, recently published in the journal Preventive Medicine (Preventive Medicine 118 (2019) 122-134). This work was conducted by J. Paul Leigh from the University of California Davis, Wesley A. Leigh from the University of Nevada, Reno, and Juan Du from Old Dominion University.
UC Davis meta-analysis study shows a $1 increase results in a 4% drop in smoking
Lower-wage workers who received a $1 raise due to an increase in the minimum wage reported a 1.4 percentage point (4% evaluated at the mean) decrease in smoking, new research from UC Davis Health shows.
The authors hope their literature review and meta-analysis study, e-published ahead of print in Preventive Medicine, expands the national conversation about minimum-wage policies to include how they affect the health of lower-wage workers and their families. The low-wage worker population has steadily grown in the U.S. over the past 17 years, according to senior author Paul Leigh.
“The minimum wage is hotly debated, but almost all of those debates involve economic issues such as the effects on unemployment and income inequality. For example, falling inflation-adjusted minimum wages are likely responsible for 50% of rising wage inequality over the past 40 years,” said Leigh, professor of public health sciences and researcher with the Center for Healthcare Policy and Research at UC Davis.
“Our results support raising minimum wages because it can lead to reductions in smoking that, in turn, can ultimately lead to reductions in medical spending,” Leigh added.
In conducting the study, Leigh and co-author Juan Du of Old Dominion University conducted a meta-analysis of 15 high-quality studies on minimum wages and public health. These 15 studies analyzed large nationally representative samples — some containing more than 100,000 subjects — from the US and the UK from years covering 1995 to 2016. Numerous health outcomes were analyzed including self-rated health, alcohol abuse, absence from work, obesity, and depression. The researchers found that these studies were relatively new; most were conducted from 2016 to 2018.
Meta-analysis is a state-of-the-art technique to evaluate and combine numerical findings from independent studies. For example, studies with more subjects are given more weight than studies with fewer subjects in the meta-analysis estimate. In additional analyses, the researchers identified the four best studies as those that compared workers’ health and behavior before and after they experienced an increase in their wages with other similar workers who did not experience an increase in their wages. The researchers also identified a fatal flaw in several studies that did not make it into the top 15. These flawed studies did not distinguish between subjects who likely received an increase in their wages versus other subjects who likely did not receive an increase.
The meta-analysis found only one consistent result across studies: increases in minimum wages resulted in declines in smoking among low-wage employees. This result was especially strong for women. The researchers did not find that increases in minimum wages lead to any health harm or increases in unhealthy behaviors such as alcohol abuse.
Results from three of the four best studies demonstrated increases in minimum wages resulted in decreases in subjects reporting depression, self-assessed poor health, and absence from work due to illness. The fourth “best” study found no effects on health or behavior, either positive or negative.
Two studies found increases in minimum wages resulted in reductions in numbers of low-birth-weight babies born to female low-wage workers.
On net, across all studies, Leigh and colleagues conclude that increases in minimum wages lead to only benefits, not harms, to the health of low-income workers and their families.
Leigh anticipates many more studies will be conducted on minimum wages on the population’s health because minimum wages receive considerable public debate and increases in minimum wages create “natural experiments” whereby researchers can compare low-wage workers in states that raised minimum wages with similar low-wage workers in states that did not raise minimum wages.
“It is uncommon to see minimum-wage-effects research that focuses on difficult-to-measure factors such as worker health, even though a less healthy workforce can be a significant drain on productivity and finances,” said Leigh. “Our review shows that researchers are increasingly gaining this focus.”
A copy of the study, titled “Minimum wages and public health: A literature review,” is available online at https://doi.org/10.1016/j.ypmed.2018.10.005. The study received no external funding.