Working Papers

1. The Last Mile to First Treatment: Search Under Uncertain Medication Availability

   Lance Gui

   Job Market Paper , 2026

   Presentations: EARIE, IIOC, UMass Boston, Villanova University, American University, Tsinghua University, APPAM

   Abstract SSRN PDF

   Consumers search for goods whose availability they cannot verify in advance. When travel costs compound this uncertainty, purchases may fail despite demand. I study these frictions in the market for buprenorphine, the leading medication for opioid use disorder. In Washington administrative claims, fewer than half of first-time patients fill their prescriptions. Normalizing each patient’s default pharmacy to zero search cost identifies search costs and preferences: a purchase elsewhere reveals further search was worthwhile. Search frictions explain 70 percent of treatment failures. Guiding patients to available pharmacies captures most of the gains from requiring every pharmacy to carry the drug.
2. Closing the Opioid Use Disorder Treatment Gap: Expanding Nurse Practitioners’ Prescriptive Authority

   Lance Gui

   Reject and Resubmit, Journal of Public Economics , 2026

   Presentation: APPAM

   Abstract SSRN PDF

   Buprenorphine is an effective treatment for opioid use disorder (OUD), yet access remains limited. I study whether expanding buprenorphine prescribing capacity increases treatment access and lowers opioid-related mortality. I exploit the 2016 Comprehensive Addiction and Recovery Act (CARA), which authorized nurse practitioners (NPs) to prescribe buprenorphine for the first time. I combine this federal reform with pre-existing state differences in NP prescribing authority, which determine how strongly CARA expands local access. Granting NPs independent prescribing authority increased active buprenorphine prescribers by 47%, increased buprenorphine dispensation by 26%, and reduced opioid-related mortality by 22%. These effects reflect new provider entry, with no evidence of displacement of existing specialists or opioid treatment programs. Effects are concentrated in previously underserved counties; counties with established access show higher dispensation but no significant mortality decline. I also find suggestive evidence of increased diversion into secondary markets.
3. Anatomy of Opioid Diversion: Examining Supply-Side Curtailment

   Lance Gui, Chuan Qin, and Mo Xiao

   2024

   Presentations: CUHK†,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. Private Equity, Mortality, and Crime: Evidence from Opioid Treatment Programs

   Lance Gui, and Austin Smith

   2026

   Presentation: APPAM*

   Abstract

   Private equity (PE) is known to lower care quality for its own patients, and we ask whether the cost stops there. Opioid treatment programs (OTPs), the only outpatient source of methadone for opioid use disorder, add counseling and medical care, and because treatment reduces local crime they also protect public safety. By 2020, PE owned more than a quarter of them. A staggered difference-in-differences design around acquisitions shows methadone volume unchanged while the clinic offers less payment assistance and less general substance use treatment. County opioid deaths rise 2.4 per 100,000, 29 percent of the pre-acquisition mean, and violent offenses rise 8 percent. Entry tells the same story: deaths and violent offenses rise where a PE-backed OTP opens, not where a non-PE-backed one does. In settings where firms produce positive externalities, PE acquisitions deserve scrutiny beyond the service sold.
2. Fast to Create, Slow to Verify

   Lance Gui, and Yi Zhang

   2026