Frontiers in public health
Paradoxical PM2.5-longevity estimates in global country panels are sensitive to differential trend control: a specification analysis, 2000-2023
Par Lu H et Lu H.
Contenu en anglais
Résumé
Background
Country-year panels are widely used for environmental health research, but heterogeneous national trajectories can produce ecological coefficients that conflict with established health evidence.
Methods
We assembled 4,406 country-year observations from 186 economies in the World Bank World Development Indicators for 2000-2023. Annual life expectancy was regressed on population-weighted ambient PM2.5 exposure using economy and year fixed effects, with adjustment for gross domestic product per capita, health expenditure, and urbanization. The original sensitivity analyses examined alternative weights, covariance estimators, exposure lags, sample restrictions, and temporal transformations; a future-exposure negative control tested residual temporal structure. Economy-specific trends and rolling five-year differences were added after the conventional estimate showed an unexpected positive sign.