Wednesday, July 29, 2026

Beyond the Median: How to Unmask the Multi-Million Dollar Appeals Tsunami in Modern Mass Appraisal

For decades, assessing offices and valuation professionals have taken shelter behind a single statistical shield: aggregate central tendency.

Chief appraisers and oversight boards point to neat median ratios near 1.00 and low CODs to certify tentative rolls, declaring statistical compliance accomplished. But in today’s volatile property tax environment, a healthy median is a dangerous illusion.

Beneath smooth central averages, traditional one-step CAMA models (sales-based models generating the Tentative Rolls) routinely embed a silent "double whammy":

1.   Severe over-assessment concentrated on lower-value and working-class properties—triggering an uncontrollable tsunami of tax appeals and Review Commission / Value Adjustment Board petitions.

2.   Massive under-assessment on high-end luxury and commercial assets—allowing billions in baseline property tax wealth to vanish untaxed.

It’s time to look beyond the median.

My upcoming book drops this Sunday, August 2nd!

In this book, I introduce the practical, two-step Double-Entry Mass Appraisal (DEMA™) framework and The Ten Commandments of Valuation Modeling. We show how assessing staff can use extended percentile audits and the Champ-Challenger approach to unmask hidden roll distortions—offering an immediately usable stop-gap solution that requires zero changes to existing CAMA workflows.

#MassAppraisal #AVM #CAMA #PropertyTax #Econometrics #RealEstateValuation #AssessmentEquity #PublicFinance 

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Beyond the Median: How to Unmask the Multi-Million Dollar Appeals Tsunami in Modern Mass Appraisal

For decades, assessing offices and valuation professionals have taken shelter behind a single statistical shield: aggregate central tendency...