Geo-SWITCH: Simulating regional income distribution and policy impacts in Ireland

Authors

Karina Doorley, Iris Wohnsiedler, Richard O’Shea, Niall Farrell, Cathal O’Donoghue

Publication Date

Jun 2026

Abstract

This paper introduces Geo-SWITCH, a spatial extension of Ireland’s tax-benefit microsimulation model SWITCH that enables distributional impact analysis at the county level. We align nationally representative SILC microdata with county-level administrative benchmarks using small-area estimation techniques, comparing deterministic calibration and probabilistic (Conditional Monte Carlo) approaches. Internal validation favour the deterministic method, which we validate externally and adopt for a range of applications including quantification of sample variability. We map county-level disposable income, revealing a spatial gradient from higher incomes in Dublin and the commuter belt to lower incomes in the North West, and incorporate bootstrap confidence intervals to quantify sampling uncertainty. We then simulate medical card eligibility, showing substantial regional variation in access to free healthcare that closely tracks income patterns. Finally, we assess Budget 2026 reforms, finding that permanent welfare increases are progressive across counties while the withdrawal of temporary cost-of-living supports disproportionately affects lower-income areas. Geo-SWITCH provides a flexible, validated tool for regional policy analysis in Ireland.

Publication type

EUROMOD Working Paper Series

Series Number

EM4/26

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