Spillover Effects and Regional Polarization: Public Investments in Morocco under the Spatial Lens

This study examines the spatially and temporally varying impact of public capital on regional economic growth in Morocco over the period 2011–2023. By specifying a flexible translog production function and estimating it using Geographically and Temporally Weighted Regression (GTWR), we account for both spatial non-stationarity and temporal dynamics across the twelve Moroccan regions. Our empirical findings uncover pronounced heterogeneity in the productivity of public investment. Coastal and economically diversified regions such as Casablanca-Settat, Rabat-Salé-Kénitra, and Tanger-Tétouan-Al Hoceïma demonstrate high and increasing output elasticities of public capital, reflecting robust complementarities with private capital accumulation and skilled labor. Conversely, interior and peripheral regions—including Drâa-Tafilalet and Beni Mellal-Khénifra—exhibit weak or insignificant effects, highlighting the limitations of a uniform infrastructure investment policy in structurally constrained territories. These results provide strong evidence of emerging spatial polarization and reinforce the need for territorially differentiated investment strategies. Our approach also demonstrates the methodological relevance of GTWR for evaluating public policy effects under spatial heterogeneity. The study contributes to the literature on regional growth, spatial econometrics, and infrastructure policy in developing economies.