The Philadelphia Housing Index (PHI) measures changes in the sales price of Philadelphia’s housing units through time, adjusting housing traits to compare like-to-like, with differentiated trends by city district.

The building traits that we control for include square footage, lot size, age, age squared and cubed, the presence of a tax abatement and its age, distance to the central business district, fireplaces, garages, central air, stories, building material, whether it’s on the corner, and some technical markers in the deed record. The goal of this is to subtract out features that affect the price besides the neighborhood it’s in.