A measure of AVM precision. The PRB is the slope in the regression of the AVM valuation-to-sales price ratios (adjusted by the median ratio) on a proxy variable that measure the value of the house. The proxy value variable is the natural log of the average of selling price and AVM valuation (all divided by 0.693). The PRB coefficient shows whether an AVM’s valuation-to-sales price ratios are systemactially higher, lower or steady as values increase. A negative value indicates regressivity, while a positive value indicates progressivity.