Who’s afraid of power lines? Merging survey and GIS data to account for spatial heterogeneity

The study offers a comprehensive assessment of the externalities produced by High Voltage Transmission Lines as perceived by residents in the infrastructure corridors. A GIS approach has been experimented in the sampling design of a CV survey in order to obtain additional information about the local context within which impacts are perceived and to take into account the spatial specificity of the external effects. We estimate, by means of a double-bounded logit model, the marginal damage from human health, landscape and environmental effects. We differentiate the analyses with separate bid designs for households in close proximity to the lines, affected by a depreciation of their real estate property values, and for all other respondents affected by generic forms of damage linked to visual encumbrance. A significant explanatory contribution in the modelled utility functions of resident households is given by the implementation of GIS-based variables, such as the proximity to power lines, built as a distance decay indicator, and local context features such as density of power lines, presence of other linear infrastructures, and local environmental amenity.