The inspiration for this post was reading America's Syringe Exchanges Might Be Killing Drug Users/The Economist, December 1, 2022. To quote: 

“A new study by Analisa Packham published in the Journal of Public Economics uncovers an uncomfortable truth: this particular harm-reduction tool does lots of harm. Ms Packham compares how drug users fared in counties that opened syringe exchanges between 2008 and 2016 with those in counties that did not. Before the clinics opened, upticks in HIV diagnoses or overdoses in one set of counties were mirrored in the other. Once a syringe exchange came to town, outcomes diverged. Rates of HIV fell by 15% in counties with the new programme. But deaths soared. On average syringe-exchange programmes led to a 22% spike in opioid-related mortality…” 

Packham’s study has been met with some rather strongly-worded criticism, as the Economist article notes: 

Leo Beletsky, a former drug dealer, now at Northeastern University, deems Ms Packham’s findings ‘nonsensical’…Don Des Jarlais, at New York University, argues that addicts do not respond to incentives like others do, making the moral-hazard effect inconceivable.” [my italics] 

Moral hazard is a situation where individuals have an incentive to increase their exposure to risk because they do not bear the full costs of that risk. I’m guessing a possible moral hazard associated with needle exchange programs is that these programs could lead to greater drug abuse by reducing the perceived risk of needles. And with opioids, more drug abuse would mean a higher likelihood of death by overdose.

Let’s just assume Des Jarlais is right: addicts don’t respond to incentives like others do and that includes responding to risk. After all, there’s plenty of research on drug abusers that support this view.  Drug abusers have repeatedly been found to be less risk averse than others (Blondel, Lohéac, et al., 2007; Cabedo-Peris et al., 2022). They also appear to take little pleasure in activities unrelated to drug use (Robinson et al, 2013). Given these tendencies, normal incentives and disincentives would likely have little effect on their drug-taking behavior. 

But needle exchange programs offer more than less risky drug-taking. They also provide places to congregate, places with easy access to dealers, fellow abusers and drug paraphernalia, the combined presence of which “may culminate in uncontrollable levels of craving and further increase the risk of relapse” (Robinson et al, 2013).  I’m not talking incentives here, but triggers for drug use. And if the triggers increase drug use, they also increase the likelihood of overdose.

I might be wrong, of course. Maybe needle exchange programs don’t increase drug use or overdose*. The way to find out is to do more research. But judging by the response so far to Packham’s work, I imagine such research would be met with resistance by the powers-that-be in the academic community. What a shame.

It is an arrogant and unscientific mindset that dismisses research findings as “nonsensical” or “inconceivable”, as if nothing could be gained from further exploration of the matter, as if the science were settled. But science is rarely settled, especially the science of human behavior. To quote How Science Works:

“Accepted theories are the best explanations available so far for how the world works. They have been thoroughly tested, are supported by multiple lines of evidence, and have proved useful in generating explanations and opening up new areas for research. However, science is always a work in progress, and even theories change.”

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* For the record, I think needle exchange programs have done a lot of good, mostly by protecting addicts from infectious disease. These programs may also help some addicts quit their habits, perhaps by connecting them to other services. And perhaps before the fentanyl epidemic, there was no connection between needle exchange programs and overdose deaths. If such a connections exists now, that doesn’t mean the programs should be shut down - just fixed. For example, if only a subset of needle exchange programs are associated with increased overdose mortality, researchers could explore how these programs differ from other programs, which could then be used as models for reform.

References:

Ainslie, G. (2013). "Intertemporal Bargaining in Addiction." Frontiers in Psychiatry 4.
https://doi.org/10.3389/fpsyt.2013.00063 

Blondel, S., Y. Lohéac, et al. (2007). "Rationality and drug use: An experimental approach." Journal of Health Economics 26(3): 643-658.  https://doi.org/10.1016/j.jhealeco.2006.11.001  

Cabedo-Peris J, González-Sala F, Merino-Soto C, Pablo JÁC, Toledano-Toledano F. Decision Making in Addictive Behaviors Based on Prospect Theory: A Systematic Review. Healthcare. 2022; 10(9):1659. https://doi.org/10.3390/healthcare10091659  

Robinson, M. J. F., Robinson, T. E., & Berridge, K. C. (2013). Incentive salience and the transition to addiction. In P. M. Miller, S. A. Ball, M. E. Bates, A. W. Blume, K. M. Kampman, D. J. Kavanagh, M. E. Larimer, N. M. Petry, & P. De Witte (Eds.), Comprehensive addictive behaviors and disorders, Vol. 2. Biological research on addiction (pp. 391–399). Elsevier Academic Press.
http://dx.doi.org/10.1016/B978-0-12-398335-0.00039-X  

Silverman, K., Holtyn, A.F. & Toegel, F. The Utility of Operant Conditioning to Address Poverty and Drug Addiction. Perspect Behav Sci 42, 525–546 (2019). https://doi.org/10.1007/s40614-019-00203-4