epidemic. noun
- an outbreak of disease that spreads quickly and affects many individuals at the same time : an outbreak of epidemic disease
- an outbreak or product of sudden rapid spread, growth, or development
The opioid epidemic is one that has impact a large number of Americans. Data from 2019 shows that there were over 15,500 deaths in 2019 due to opioids. Many epidemics are contagious in nature in that they spread from one person to another. Could this type of contagious disease model be applied to the opioid epidemic as well?
According to an NBER paper by Adamopoulou et al. (2024) the answer is ‘yes’. When a person has a friend that uses opioids, that individual is much more likely to use opioids.
Using data from the National Longitudinal Survey of Adolescent Health (Add Health), adults aged 25-34 and their high school best friends are focused on. An instrumental variable technique is employed to estimate peer effects in opioid misuse. Severe injuries in the previous year are used as an instrument for opioid misuse in order to estimate the causal impact of someone misusing opioids on the probability that their best friends also misuse. The estimated peer effects are significant: Having a best friend with a reported serious injury in the previous year increases the probability of own opioid misuse by around 7 percentage points in a population where 17 percent ever misuses opioids. The effect is driven by individuals without a college degree and those who live in the same county as their best friends.
The full working paper is here. Hat tip to Marginal Revolution.