Axis Philly was able to obtain a 936 page document detailing the City's own assessment of its AVI assessments, and it proves that the city knows they're far from perfect. Though the city is mostly pleased with its performance, and the document boils down, basically, to "high fives all around," there is evidence that in some areas, the "Coefficient of Dispersion," or, in layman's terms, "Level to Which We Were Wrong," was higher than 15%.
The Coefficient of Dispersion was reached by calculating the percentage difference between a home's sale price and its assessed taxable value. Although the city assigned 15% as its acceptable Coefficient of Dispersion, many areas including Germantown, North Philly, West Philly, and place near Center City had percentages that were much higher.
The data was secured via a Right-to-Know request and cost the requester $234.
· Internal AVI documents show some parts of city more accurately assessed than others [Axis Philly]