Geography plays a significant role in the opioid crisis, according to research co-authored by MIT economists. The study, published in the Quarterly Journal of Economics, examined data on prescription opioid use from adults in the Social Security Disability Insurance program from 2006 to 2019, covering about 3 million cases. The research found a somewhat greater role for place-based factors than for personal characteristics in accounting for risky opioid use.
Risky use was defined as an average daily morphine-equivalent dose of more than 120 milligrams, which has been shown to increase drug dependence. When someone moves to a state with a 3.5 percentage point higher rate of risky use—similar to moving from the state with the 10th lowest rate to the state with the 10th highest rate—their probability of risky opioid use would increase by a full percentage point in the first year, then by 0.3 percentage points in each subsequent year.
Laws Restricting Pill Mills
Laws restricting pain clinics, or “pill mills,” where opioids were often prescribed, reduced risky opioid use by 5 percent over the 2006-2019 study period. However, due to the path of addiction, enacting those laws near the onset of the crisis in the 1990s could have reduced risky use by 30 percent over the same time. The researchers identified state-level policies that lagged in restricting pill mills, and found this trend particularly pronounced in over a dozen states.
The Addiction Channel
The study examined two mechanisms: the “addiction channel,” where opioid users fall into addiction, and the “availability channel,” where already-addicted individuals find ways to sustain their use. Over 2006-2019, people falling into addiction through new prescriptions had an impact on overall opioid uptake 2.5 times as large as that of existing users getting continued access to prescribed opioids.
When non-users move to places with higher rates of risky opioid use, there is no immediate change in behavior, but gradually an increase in risky opioid use occurs—consistent with a scenario where a person has a health issue and receives opioid prescriptions from local doctors more likely to prescribe. By contrast, already-risky users moving to high-use areas show an immediate increase in opioid use, suggesting increased availability. As opioid use became restricted, addiction persistence remains a central problem. Even after the role of prescription opioids subsides, the opioid crisis persists, driven by the persistence of addiction.
This article is an AI-assisted summary. All facts and figures are drawn from the original report: https://news.mit.edu/2025/study-reveals-geography-role-opioid-crisis-1030