Why do aircraft noise value estimates differ? A meta-analysis

Placing a monetary value on aircraft noise is necessary in order to assess the social cost inflicted by aviation. This need has given rise to a considerable amount of hedonic price (HP) studies on the relation between property values and aircraft noise, both published and unpublished. The present paper performs a statistical analysis of previous HP valuation results, also known as meta-analysis. A set of nineteen studies provides thirty estimates of the Noise Depreciation Index (NDI): a simple test shows that studies display variation among their respective NDI estimates. This variation may, however, be explained by variables representing timing, sample wealth, and specification of the original studies.