A man injects heroin into his arm. (David Goldman/Associated Press)

Anne Case is the Alexander Stewart 1886 professor of economics and public affairs emeritus at Princeton University. Angus Deaton is the Dwight D. Eisenhower professor of economics and international affairs emeritus at Princeton University and the 2015 Nobel laureate in economics.

Lawmakers and the media have devoted much of their attention recently to deaths from opioid overdoses, as well as to the broader "deaths of despair" that include suicides and deaths from alcoholic liver disease and cirrhosis. But despite the intense focus on the topic, misinformation about the epidemic runs rampant.

By conventional wisdom, tackling this crisis would require extending Medicaid and improving how it functions, cracking down on prescription painkillers and getting more health-care resources into rural communities.

But that’s not exactly right. To correct the record, here are four points to bear in mind:

Medicaid isn't the problem (and isn't the solution). Critics of Medicaid argue that the program enables the epidemic by paying for prescription opioids. In fact, Princeton University researchers Janet Currie and Molly Schnell calculate that only 8 percent of all opioid prescriptions from January 2006 to March 2015 were paid for by Medicaid, based on data from QuintilesIMS, a leading health-care information company.

Medicaid can help addicts by providing a range of evidence-based therapies. This is correct and, like many others, we think treatment is a good idea. As such, we are also concerned about the effects that reductions in Medicaid could have on the epidemic. But Medicaid proponents often greatly overstate what can be expected from treatment in general, and Medicaid in particular. Many addicts deny their addiction and either do not seek or do not adhere to treatment once started. “Evidence-based” typically means there has been a randomized, controlled trial that has demonstrated effectiveness. But trials include only those who seek treatment — and say nothing about those who avoid it. A trial is deemed successful when the treatment is proved better than nothing (or at least a placebo) — even if only a few people end up benefiting from it.

It is not all about opioids. Policymakers often speak as if the epidemic will be over as soon as we tackle both legal and illegal opioids. Better control of opioids is essential, but, even without opioid deaths, there would still be as many or more deaths from suicide and liver diseases. Opioids are like guns handed out in a suicide ward; they have certainly made the total epidemic much worse, but they are not the cause of the underlying depression. We suspect that deaths of despair among those without a university degree are primarily the result of a 40-year stagnation of median real wages and a long-term decline in the number of well-paying jobs for those without a bachelor's degree. Falling labor force participation, sluggish wage growth, and associated dysfunctional marriage and child-rearing patterns have undermined the meaning of working people's lives as well.

The crisis has hit men and women about equally. There are competing myths that women (or men) have faced the greater brunt of the epidemic. In fact, the increase in deaths of despair has been similar for men and women. It is true that women are less likely to kill themselves than men, and they have lower death rates throughout life. As a result, the same increase in deaths among both sexes translates into a larger percentage increase for women. But the numbers of additional deaths remain similar. A focus on men appears to reflect a prejudice that the social pathologies connected to the epidemic — drinking and drugging — are primarily seen in men. That has led some to believe that men are more prone to deaths of despair, but again, the data do not support that claim.

Rural Americans are not alone in this crisis. While mortality rates are somewhat lower in the suburbs of large cities than elsewhere, deaths of despair have risen in parallel in all levels of urbanization defined by the Census Bureau, from inner cities to rural areas. They have increased for middle-aged whites — not blacks or Hispanics — in every state between 1999 and 2015, with deaths concentrated among those who do not have a four-year college degree. This is a statement of fact, not a claim that more education would bring the deaths under control.

There is no simple policy solution to this epidemic. In the short run, we need to develop less tolerance for the use of opioids — both legal painkillers and illegal forms of the drug, such as heroin and black-market fentanyl. Perhaps local communities have the best chance of doing so.

But the long-run solution is much harder to attain. We need higher wages and better jobs for working people. The past 40years suggest that is a far more difficult goal to attain.