Pharmacist direct-authority naloxone laws do not show preregistered attenuation under fentanyl dominance in a state-year DiD

Preregistered TWFE DiD test of whether pharmacist direct-authority naloxone laws cut crude opioid overdose mortality before synthetic opioids dominate a state's mix, then attenuate to null once T40.4 accounts for at least half of opioid overdose deaths. On the pinned panel (601 state-years, 2008–2021), ATT before dominance is -0.632217 (CI -4.144376 to 2.879942); the Law×SyntheticDominant interaction is 0.231578; ATT when dominant is -0.400639. Locked success flag false is false (decision refute). Re-run from code/analyze.py.