Data Practices for Studying the Impacts of Environmental Amenities and Hazards with Nationwide Property Data

Abstract

We discuss data quality and modeling issues inherent in the use of nationwide property data to value environmental amenities. By example of Zillow’s Transaction and Assessment Database, a real estate database covering the United States, we identify challenges and propose guidance for (1) identifying arm’s-length sales; (2) geolocating parcels and buildings; (3) identifying temporal links between transaction, assessor, and parcel data; (4) identifying property types, such as single-family homes and vacant lands; and (5) dealing with missing or mismeasured data for standard housing attributes. We review current practice and show that how researchers address these issues can meaningfully influence research findings. (JEL Q51)