Short-Term Rentals, Tourism Pressure and Spatial Externalities in Insular Destinations: Evidence from Santorini, Greece

The present research examines the spatial dynamics and impact of Short-Term Rentals (STRs) in highly touristic and spatially constrained insular territories, using the island of Santorini (Thira), Greece, as a case study. Unlike large metropolitan areas, where tourism pressure can diffuse across space, islands present limited land availability and infrastructure capacity, thereby intensifying the potential externalities of uncontrolled STR expansion. The study examines how STRs are spatially distributed, their interactions with formal accommodation facilities, and the extent to which they have penetrated residential, rural, and other legally protected areas. The analysis integrates Airbnb listings with land use, regulatory, environmental, and other datasets, applying specific metrics, including the Average Nearest Neighbor Index, Kernel Density Estimation, Standard Deviation Ellipses, Global Bivariate Moran’s I, and Local Collocation Quotient. The results reveal increased spatial clustering in high-amenity areas, a high degree of professionalization, and increased presence of STRs outside formal settlements. STRs exhibit colocation with formal accommodation in high-tourism zones, as well as a spillover effect in areas where hotel activity is prohibited. This underscores the need for an island-specific spatial analysis to support integrated planning and regulatory approaches that address STR-related impacts on tourism-dependent islands.