Measuring the extensive margin of a hidden market: evidence from Spain

This article introduces a longitudinal, venue-level dataset documenting the spatial and temporal evolution of a specific segment of an informal market in Spain between 2011 and 2023. Using publicly available Google data, we construct a panel of establishments classified within nightlife and adult entertainment categories, commonly referred to in Spanish as clubes de alterne. The primary contribution is methodological: we propose a transparent and replicable framework to track the commercial infrastructure of partially regulated markets that are opaque to standard measurement. The dataset captures the extensive margin of supply the presence and persistence of physical venues and should be interpreted as a conservative, observable lower bound. We document pronounced spatial concentration and heterogeneity across provinces, with establishments clustering in major urban and coastal tourist areas. This dataset provides a new empirical tool to study the interaction between informal markets, regulation and local economic dynamics.