The opioid epidemic in the United States, which the Department of Health and Human Services declared a public-health emergency in 2017, continues to escalate. To figure out how to resolve it, policymakers should look for lessons in what may seem to be an unrelated episode: the 2008 global financial crisis.

To be sure, the HHS has recently introduced a new coordinated strategy to address the opioid crisis. That strategy includes the Food and Drug Administration's Opioids Action Plan, which aims to reexamine the underlying risk-benefit paradigm for opioids and to reduce the number of prescriptions for opioid painkillers through education programs.

But the HHS strategy fails to address adequately one of the main causes of the opioid crisis: aggressive commercial and marketing tactics by pharmaceutical companies. While the FDA's Office of Prescription Drug Promotion focuses on "ensuring that prescription drug information is truthful, balanced, and accurately communicated", it does not do enough to control the incentives provided by drug manufacturers to prescribers and patients.

Just as the promotion of opioid painkillers like OxyContin (sold by Purdue Pharma) has been a key driver of the opioid crisis, unethical "hook strategies", facilitated by lax mortgage-lending practices, were a major cause of the 2008 financial crisis. In both cases, many individuals were lured into making risky decisions－whether taking out a mortgage they couldn't afford or treating their pain with a highly addictive drug－by attractive "introductory offers."

In the case of the financial crisis, low-and middle-income borrowers were convinced to take out subprime (high-risk) loans with low "teaser" interest rates. But those rates would, after a set period, increase substantially－often to levels that the borrowers could not afford. In extreme cases, banks even granted so-called NINJA (no income, no job, and no assets) loans. When the crisis struck, many of these high-risk borrowers lost their homes.

In the case of the opioid crisis, pharmaceutical companies have offered free samples and savings coupons to doctors, who then prescribed to patients who often were not made fully aware of the addictive nature of the substances they were consuming. Many of these patients then became addicted to opiates, with a large number of them eventually dying from drug overdose.

While asymmetric information and irresponsible incentives were major causes of both crises, other factors helped to amplify their effects. In the case of the financial crisis, one such factor was securitization, the process whereby subprime loans were pooled and sold as asset-backed securities, which created a powerful incentive to originate increasingly risky loans. When the mortgage bubble burst, the market for mortgage-backed securities collapsed, and undercapitalized banks that had loaded up on them found themselves struggling to survive.

During the opioid crisis, the major amplifying mechanism has been illegal opiates. Patients become addicted to prescribed painkillers, which, while dangerous, comprise known ingredients and, when used properly, have predictable dosages. But eventually those prescriptions dry up, inducing addicted patients to turn to illegal alternatives, which are even more likely to lead to fatal overdose.

So far, much more has been done to counter the mechanisms behind the financial crisis than those fueling the opioid crisis. As of February 2018, lawsuits against banks had resulted in an estimated $243 billion in fines and settlements. By contrast, as of May 2018, pharmaceutical companies and prescription drug distributors had faced only about $953 million in fines and settlements (mostly, but not only, against Purdue Pharma), though many lawsuits are still pending.

The regulatory response has been similarly lopsided. On the financial front, the US Congress has created the Consumer Financial Protection Bureau to oversee financial products and services that are offered to consumers. Since January 2014, the CBFP has reined in the use of introductory pricing in mortgage loans, by requiring lenders to verify that borrowers have the assets and income prospects needed to make payments throughout the life of the loan.

With regard to the opioid crisis, an equivalent strategy, which should include banning free samples, would limit pharmaceutical companies' marketing tactics. But no such initiatives have yet been introduced in the US.

If the US pharmaceutical industry has anything to say about it, they never will be. Just as the financial sector is resisting the CBFP, the Pharmaceutical Research and Manufacturers of America, the largest drug-lobby group in the US, vigorously defends the practice of providing free samples of prescription drugs to physicians.

Despite the inevitable pushback, official action to end that practice is possible. After the European Council issued a directive in 2001 stating that free samples will be provided only on an "exceptional basis" and prohibiting the supply of samples of "medicinal products containing psychotropic or narcotic substances", European pharmaceutical companies complied. The European Federation of Pharmaceutical Industries and Associations later introduced the healthcare professional code, which states that "medical samples must not be given as an inducement to recommend, prescribe, purchase, supply, sell or administer specific medicinal products, and should not be given for the sole purpose of treating patients".

According to the HHS, an estimated 130 or more people died from opioid-related drug overdoses each day in 2016 and 2017－a period during which 2 million people misused prescription opioids for the first time. Unless regulators limit how addictive prescription drugs are marketed in the US, the crisis will continue to grow－and the body count will continue to rise.

Mathias Dewatripont, Professor of Economics at the Université libre de Bruxelles and co-director of the Institute for Interdisciplinary Innovation in Healthcare, was Executive Director of the National Bank of Belgium and a member of the Basel Committee on Banking Supervision and the Supervisory Board of the European Central Bank. Michel Goldman, the founder and co-director of the Institute for Interdisciplinary Innovation in Healthcare (I3h) and Professor of Immunology and Pharmacotherapy at the Université libre de Bruxelles, served as Executive Director of the Innovative Medicines Initiative (IMI) from 2009 to 2014. Project Syndicate