Abstract This paper constructs the first long‐run estimates of Irish regional gross domestic product (GDP) over the twentieth century and traces the relative economic performance of Ireland's regions since independence. Using an array of data sources available at a county level, output in agriculture, industry, and services in benchmark census years is estimated. Applying a variety of alternative measures, we find a reduction in regional inequality over the period that resembles the broader European pattern. Regional convergence over the period 1926–91 was driven by both within‐sector convergence in productivity and structural change. Our paper helps us understand the regional dimensions of Irish economic development from the birth of a newly independent state up to the eve of Ireland's growth ‘miracle’ in the 1990s, when the first official efforts were initiated to construct these figures. Finally, we connect our regional estimates to the first official figures to study the evolution of Irish regional development up to 2021.
Bromhead et al. (2025) studied this question.