Geographic and Temporal Variation in Housing Filtering Rates

Abstract

In the field of Housing Economics, filtering is the process by which properties, as they age and depreciate in quality, tend to be occupied by lower-income households. This is the primary mechanism by which competitive markets supply low-income housing. While filtering is an important long-term source of lower-income housing at the national level, this research shows that filtering rates for owner-occupied properties vary considerably both across and within metropolitan statistical areas. Notably, in some markets, properties “filter up” to higher-income households. This paper contributes to our understanding of filtering by demonstrating the geographic and temporal heterogeneity of filtering rates and examining links between filtering, supply elasticity, and gentrification. We also explore two alternative measures of filtering based on changes in relative income rather than real income.

Keywords: filtering, affordable housing, repeat income model

JEL Classification: R21, R31, R38