Working Papers

1. The Last Mile to First Treatment: Search for Opioid Use Disorder Medication

   Lance Gui

   Job Market Paper , 2025

   Presentations: APPAM*, Tsinghua University*

   Abstract SSRN PDF

   Despite growing policy support for buprenorphine, the leading medication for opioid use disorder, treatment initiation remains low. Comprehensive insurance data from Washington State show that fewer than half of first-time patients fill their prescriptions, well below rates for other chronic conditions. Initiation is hindered not only by the physical cost of visiting pharmacies (e.g., distance) but also by uncertainty about availability. I estimate their joint effect using a structural sequential search model where patients search over pharmacies with unknown availability. Normalizing the default (most frequently visited) pharmacy’s search cost to zero, I identify search costs by comparing non-default choices (utility net of search costs) to default choices (utility only). I find that search costs account for 70% of observed treatment failures. Counterfactuals show that simple prescriber guidance on pharmacy availability could raise initiation rate by 17%.
2. Closing the Opioid Use Disorder Treatment Gap: Expanding Nurse Practitioners’ Prescriptive Authority

   Lance Gui

   2025

   Presentation: APPAM*

   Abstract SSRN PDF

   Buprenorphine, like nicotine gum for quitting smoking, provides a safe treatment for opioid withdrawal, yet access remains limited. The 2016 Comprehensive Addiction and Recovery Act (CARA) enabled Nurse Practitioners (NPs) to prescribe buprenorphine. Leveraging pre-existing state-level NP prescribing authority and comparing pre- and post-CARA periods, I find that allowing NPs to prescribe buprenorphine independently expands the pool of active buprenorphine prescribers, increases buprenorphine dispensation, and reduces opioid-related mortality by over 20%, without replacing specialized treatment. Gains were concentrated in underserved counties, with limited effects elsewhere. Finally, there is suggestive evidence of increased diversion into the secondary market.
3. Anatomy of Opioid Diversion: Examining Supply-Side Curtailment

   Lance Gui, Chuan Qin, and Mo Xiao

   2024

   Presentations: Leuven IO Conference†, Yale†, PUC Chile†, SUFE-Jinan Empirical IO Conference, University of Toronto†, IIOC, Caltech Structural Microeconomics Conference†, EARIE

   Abstract SSRN PDF

   Pharmacies should act as gatekeepers of opioid distribution. However, rogue pharmacies divert opioids to non-medical users, worsening the opioid epidemic. We examine the spatial redistribution of opioids dispensed following targeted shutdowns by the Drug Enforcement Administration, employing comprehensive pharmacy-level opioid shipments and hospital diagnoses data in ten U.S. states. The displacement of local opioid shipments after removing a pharmacy unveils the extent of non-medical use: medical users can readily switch to competing local pharmacies, while non-medical users cannot. We develop and estimate a structural model to study medical and non-medical consumers’ substitution patterns facing changes in their consideration sets. We find that 8% of pharmacies sell non-medical use opioids with a probability greater than 90% and that over half of pharmacy-dispensed opioids are diverted to non-medical use. Aggressive pharmacy crackdowns, however, drive a substantial portion of non-medical users who lose access to the black market, which may lead to the rise of more dangerous narcotics such as heroin and fentanyl.
4. Anatomy of a Scandal: #Batterygate and Consumer Choice

   Lance Gui

   Draft available upon request , 2022

   Presentation: Chinese Economists Society Annual Meeting

   Abstract

   I link the Twitter activity of over 35,000 individuals to their offline phone purchasing decisions to examine the consumer response—across both existing and potential customers—to the Batterygate scandal. This incident refers to Apple’s 2017 decision to slow down iPhone processors without disclosing the reason, which was to preserve battery life. To address concerns about the parallel trends assumption, I use a novel trend-extrapolated Differences-in-Differences technique that assumes pre-existing trends for the treatment and control groups would have continued without intervention. My findings reveal that Batterygate negatively affected potential consumers but had no impact on the current user base. This suggests that consumer heterogeneity is a crucial factor in determining how customers respond to even uniformly negative media coverage.

Work in Progress

1. Involuntary Rehabilitation

   Lance Gui, and Austin Smith