Climate Migration in Serbia: Quantification Using a Difference-in-Differences Approach

This study examines whether the municipalities classified as flood-affected during the May 2014 floods experienced a differential change in formally registered internal out-migration relative to non-flooded municipalities. The analysis uses a balanced municipality-year panel for 2009–2018, comprising 40 flood-affected and 125 non-flooded municipalities, with municipality and calendar-year fixed effects. The primary estimate is positive but imprecise (0.239 per 1,000 residents; 95% CI: −0.423 to 0.901). A restricted matched-sample estimate is larger but also imprecise, while a specification allowing NUTS2 region-specific annual shocks produces a larger positive estimate. Event-study and placebo diagnostics provide no statistical evidence of differential pre-treatment changes, although their confidence intervals are wide. Exploratory analyses suggest that estimated responses may vary by selected pre-flood municipal characteristics, but they do not identify household-level mechanisms. The findings do not support a single specification-invariant estimate of a positive average flood effect; they show that the estimated municipality-level association is sensitive to the comparison group and the treatment of regional annual shocks.