Although the fact is not widely acknowledged by urban scholars, because of the way that it is administered the property tax helps to shape the social geography of metropolitan areas. Research by public finance specialists has shown that cheap housing is often overassessed, and that variations in assessment ratios (the ratio of assessed to market values) usually favour the suburbs. Sales prices and assessment data from the Hamilton, Ontario, metropolitan area for 1976, 1996, and 1999 confirm these patterns and show that they are persistent. In addition, cross-tabulations by market value and location show that geographical variations in assessment ratios are caused by the inequitable treatment of inexpensive property, not vice versa. A 1998 reassessment made the situation worse. The main difficulty in reducing tax inequities is political, not technical.