Poisson + Negative-Binomial IRR for volatility ~ alert complexity
Source:R/otis_churn.R
morie_otis_irr_glmm_vm.RdBuilds the (id x fiscal year) cell with outcome
vm (number of distinct regions visited) and treatment
T_high_ac = 1 if the person-year alert-complexity ac >=
2, then fits Poisson and (optionally) negative-binomial GLMs
adjusting for Year, Gender, and Age. The NB fit uses
MASS::glm.nb when available; if not, only Poisson is
reported.