Can We Measure from the Bottom Up? Constructing an Index of Gas Station Infrastructure to Identify Regional Economic Development

We develop a methodology that leverages open-source geospatial data on fuel station infrastructure and related services to construct the Gas Station Index (GSI), a novel indicator that augments official and alternative measures of regional economic development. Gas stations serve as consumer-facing infrastructure nodes, and their density and quality reflect local demand, purchasing power, and mobility. Using data on 19,033 stations across 62 regions in nine European countries, the GSI explains 64% of the cross-regional variation in GDP per capita - a notable result for a single-variable indicator. Beyond its statistical fit, the GSI uncovers meaningful economic patterns. It reflects diminishing returns to infrastructure, consistent with core economic theory; it maps spatial inequality both visually and statistically, highlighting clusters of prosperity in capitals, port cities, transit corridors, and tourist destinations; and it classifies regional development typologies through bivariate LISA analysis. The unexplained variation underscores the structural differences between infrastructure-based indicator and GDP per capita, driven by sectoral specialization, mobility patterns, and informal economic activity. The GSI should therefore be viewed not as a substitute for national accounts, but as a complementary indicator particularly relevant at the subnational level. Compared to existing indicators, it offers distinct advantages: GDP per capita is delayed and masks heterogeneity, while night-time lights suffer from saturation and rural undercoverage. By contrast, the GSI provides a ground-level, behaviorally grounded, and real-time measure of economic development. By capturing both infrastructure and consumption dynamics, it complements—and in certain respects surpasses—conventional indicators in tracing regional growth trajectories and spatial inequality.