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

The traditional one-step CAMA model — a sales-based approach that directly generates Just Values on the entire Tentative Roll without further advanced algorithmic checks and balances — looks good on paper until the appeals tsunami hits.

In this practical guide, forensic valuation expert Sid presents Double-Entry Mass Appraisal (DEMA™) — a two-step framework that treats valuation modeling the way modern accounting treats bookkeeping. The traditional one-step CAMA system is classic Single-Entry Bookkeeping: it models the sale and generates the roll, then stops. DEMA™ supplies the missing second entry: population-based equalization that cleans and balances the Tentative Roll before it becomes final. Building on this double-entry system, he demonstrates a clear two-section valuation framework:

· Section 1 – Sales-Based Modeling (the First Entry)

· Section 2 – Population-Based Equalization (the Second Entry)

Together they form DEMA™ — the practical antidote to Single-Entry CAMA failures. Using a powerful Champ-Challenger framework, he reveals how the same model can systematically over-assess one area while under-assessing another — creating massive horizontal and vertical inequity, litigation exposure, and lost revenue. Readers also receive an immediately usable stop-gap tool: extended percentile ratio analysis that assessing staff can apply today without changing their existing workflow or software.

Whether you are an assessing professional, VAB member, Review Commission participant, or independent consultant, this book gives you the tools to strengthen the Tentative Roll, reduce costly appeals, and enforce true equity.

Stop reacting to problems. Start preventing them. The future of mass appraisal is proactive. The future is Beyond the Median.

By Sid Som, MBA, MIM

Copyright August 2026

ISBN: 9798190223194