In a pair, we replicated and extended Chrisinger (2021)’s paper “Philadelphia’s Excise Tax on Sugar-Sweetened and Artificially Sweetened Beverages and Supplemental Nutrition Assistance Program Benefit Redemption” in R.
We analyzed policy impacts across 4 counties and 50+ months of longitudinal data. While we replicated similar trends, the magnitude of the effects differed and our models lacked robustness. We extended the analysis with leave-one-out robustness checks, which revealed donor-pool sensitivity and model instability.