Announcing Sessions 2–5 of the Mass Appraisal Modeling Masterclass Series

Building on the launch of Session 1 (Representative Sales Sampling), we are taking a progressive, hands-on approach to valuation modeling across the next four sessions of our Substack & Patreon series.

Sessions 2–5 move from Basic → Intermediate → Advanced → Sophisticated model-building.

Why this progressive roadmap?

Valuation modeling shouldn't be an all-or-nothing jump into black-box algorithms. By stepping sequentially from foundational linear regressions to sophisticated econometric guardrails, newcomers learn not just how to specify models, but why each layer of complexity is introduced to ensure statutory assessment uniformity.

The core methodology stays uniform across all four (OLS regression, Months-Since time adjustment, location dummies, 2-Pass iteration, Z-score outlier protocol, and full diagnostics aimed at BLUE status). What changes is the complexity of the data and variables — giving newcomers a clear on-ramp while still delivering advanced techniques for experienced analysts and consultants.

Session 2 (Basic Modeling) drops next.
Sessions 2–5 are available to paid subscribers (Executive Summary is free).

Session 1 remains 100% free to read.

Read Session 1 and subscribe to Sessions 2–5 here:

https://sidsom.substack.com/p/sales-representativeness-testing

#MassAppraisal #CAMA #AVM #Econometrics #IAAO #AssessmentRoll #AssessmentEquity #PropertyTax #ValuationModeling #USPAP #SaveTheChildren

This weekend only — 50% off five books (PDF downloads)

Whether you work in mass appraisal, AVMs, CAMA systems, or just want clearer thinking about advanced analytics, these titles were written to be used at the desk—not left on a shelf. This weekend, 100% of proceeds from these five PDF downloads go to charity (including Save the Children). Grab the set, sharpen your craft, and put your purchase to work for something larger.

Titles included:

1.   101 Key Terms for Valuation Modeling: A Practical Desktop Reference for Mass Appraisal, CAMA, and AVM Practitioners

https://payhip.com/b/6KT2Z

2.   Valuation Modeling: The Perfect Crossover between AVM and CAMA

https://payhip.com/b/3G9gs 

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

https://payhip.com/b/PcIyf

4.   Equalization Valuation Modeling (EVM) for Smaller and Mid-Sized Jurisdictions: Foundations & Model Development

https://payhip.com/b/8foNn

5.   Forensic Valuation Modeling: Fixing Costly Errors, Bridging Missing Links (Building More Defensible Models and Achieving BLUE Status)

https://payhip.com/b/VXhb2

Important: Use coupon code CHARITY50 at checkout for a 50% discount.

Direct download via Payhip. Campaign ends Sunday night.

If you’ve been meaning to pick them up, or know someone who could benefit, now is a good time.

Thank you for your support.
Sid

This weekend only — 50% off five books (PDF downloads)

Whether you work in mass appraisal, AVMs, CAMA systems, or just want clearer thinking about advanced analytics, these titles were written to be used at the desk—not left on a shelf. This weekend, 100% of proceeds from these five PDF downloads go to charity (including Save the Children). Grab the set, sharpen your craft, and put your purchase to work for something larger.

Titles included:

1.   101 Key Terms for Valuation Modeling: A Practical Desktop Reference for Mass Appraisal, CAMA, and AVM Practitioners

https://payhip.com/b/6KT2Z

2.   Valuation Modeling: The Perfect Crossover between AVM and CAMA

https://payhip.com/b/3G9gs 

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

https://payhip.com/b/PcIyf

4.   Equalization Valuation Modeling (EVM) for Smaller and Mid-Sized Jurisdictions: Foundations & Model Development

https://payhip.com/b/8foNn

5.   Forensic Valuation Modeling: Fixing Costly Errors, Bridging Missing Links (Building More Defensible Models and Achieving BLUE Status)

https://payhip.com/b/VXhb2

Important: Use coupon code CHARITY50 at checkout for a 50% discount.

Direct download via Payhip. Campaign ends Sunday night.

If you’ve been meaning to pick them up, or know someone who could benefit, now is a good time.

Thank you for your support.
Sid

New Series Launch: Mass Appraisal Modeling Masterclass

Session 1: Sales Representativeness Testing — The First Rule of Valuation Modeling

Today, I’m launching the first session of our new mass appraisal modeling masterclass series — and it is FREE.

We start with the non-negotiable foundation: Sales Representativeness Testing.

Before calibrating an OLS engine, running spatial GIS regressions, or testing Price-Related Differential (PRD), every modeler faces a critical gatekeeper test: Is your sales sample truly representative of the population?

Skipping or rushing this foundational check compromises model integrity, induces systemic assessment drift, and leaves valuation models vulnerable during Value Adjustment Board (VAB) or judicial appeals.

Read Session 1 completely FREE today on Substack:

https://sidsom.substack.com/p/sales-representativeness-testing

Subscriber Note & Mission:

·        Session 1 is available completely free to establish our baseline diagnostic framework.

·        Sessions 2 through 10—covering time adjustment, dummy coding, ordinal coding, 2-pass outlier protocol (z-score), sales ratio analysis, OLS assumption tests, holdout tests, IAAO guidelines tests, and model application—will be exclusive to paid Substack subscribers. Of course, the Executive Summaries are always free for everyone on Substack and Patreon.

·        100% of all author proceeds from Substack subscriptions and book sales are donated directly to charitable causes, including Save the Children.

Read, share with your assessment teams, and let’s keep pushing mass appraisal toward econometric excellence.

#MassAppraisal #AVM #ValuationModeling #CAMA #Econometrics #Assessment #PropertyTax #SaveTheChildren #GIS #DataAnalytics

Announcing the Launch of the Mass Appraisal Modeling Masterclass Series on Substack!

Starting this Wednesday, September 23, 2026, I am kicking off a brand-new, 10-part weekly series dedicated to transforming mass appraisal practice through forensic econometric rigor.

Whether you are a CAMA modeler, chief appraiser, assessment specialist, or valuation analyst, this series provides a practical, step-by-step roadmap to building models that meet the highest technical standards.

What to Expect Across the 10 Weekly Sessions:

·        Session 1 (Launch): Representative Sales Sampling — Auditing sample integrity and P10–P90 percentile distribution stability before running a single model (the non-negotiable first step!).

·        Sessions 2–5: Regression Models — Calibrating four distinct OLS models using real county datasets, featuring dummy location coding, time adjustments, ordinal encoding, 2-pass regression, Z-score outlier trimming, and conditional variable parsimony.

·        Session 6: Sales Ratio Analysis — Comparative diagnostics evaluating initial predictive accuracy across all four models.

·        Session 7: Holdout Testing — Rigorous cross-validation on out-of-sample sales to guard against overfitting.

·        Session 8: OLS Assumption Diagnostics — Comprehensive checks for multicollinearity (VIF), homoscedasticity, non-linearity, and residual normality.

·        Session 9: IAAO Guidelines & Performance Audits — Verifying compliance using COD, PRD, PRB, and extended percentile diagnostics.

·        Session 10: Model Application & Just Value Ratio Analysis — Roll generation across the untransacted population and final assessment uniformity verification.

No Representative Test = No Model.

Achieving True BLUE Status

In this series, I will demonstrate how proper specification and multi-pass diagnostic routines allow our models to achieve Best Linear Unbiased Estimator (BLUE) status—bringing an uncompromised econometric standard that legacy CAMA software environments simply do not deliver.

Subscriptions & Charitable Mission

·  Subscription: $6/month

·  Executive Summary is always free for everyone on Substack.

·  100% Impact: All author proceeds from Substack subscriptions are donated directly to charitable organizations, including Save the Children.

· Stay tuned for the Session 1 link on Substack.

This weekend only — 50% off five books (PDF downloads)

 A mix of practical valuation modeling titles and other works.

Whether you work in mass appraisal, AVMs, CAMA systems, or simply want clearer thinking about advanced analytics, these titles were written to be used at your desk—not left on a shelf. This weekend, 100% of proceeds from these five PDF downloads go to charity (including Save the Children). Grab the set, sharpen your craft, and put your purchase to work for something larger.

Titles included:

1. Challenging Your Property Assessment: The Art of the Rebuttal (A Comprehensive Guide to Winning Property Tax Appeals)

https://payhip.com/b/01uD3

2. Enhancing High-Volume Comparable Sales Processing with Regression Models

https://payhip.com/b/tKQ8p

3. Making Valuation Modeling (AVM and CAMA) More Econometric

https://payhip.com/b/QU4j1

4. Tax Justice: A Blueprint for Replacing Property Taxes with Middle-Class-Friendly Reforms

https://payhip.com/b/shTKm

5. The Nomad's Compass: A Data-Driven Guide to Global Retirement and Investment

https://payhip.com/b/G1a8u

Important: Use coupon code CHARITY50 at checkout to get 50% off.

Direct download via Payhip.
Campaign ends Sunday night.

If you’ve been meaning to pick them up, or know someone who could benefit, now is a good time.

Thank you for your support.
Sid

This weekend only — 50% off five books (PDF downloads).

A mix of practical valuation modeling titles and other works. 

All proceeds support charities, including Save the Children.

Titles included:

1. 101 Key Terms for Valuation Modeling: A Practical Desktop Reference for Mass Appraisal, CAMA, and AVM Practitioners

Link: https://payhip.com/b/6KT2Z

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

Link: https://payhip.com/b/PcIyf

3. Equalization Valuation Modeling (EVM) for Smaller and Mid-Sized Jurisdictions: Foundations & Model Development

Link: https://payhip.com/b/8foNn

4. Valuation Modeling: The Perfect Crossover between AVM and CAMA

Link: https://payhip.com/b/3G9gs

5. Country Analysis: Decoding the World with Data

Link: https://payhip.com/b/agvPS

Important: Use coupon code CHARITY50 at checkout to get 50% off.

Direct download via Payhip.
Campaign ends Sunday night.

If you’ve been meaning to pick them up, or know someone who could benefit, now is a good time.

Thank you for your support.
Sid

Official Launch Announcement: 101 Key Terms for Valuation Modeling

Today I’m releasing a focused desktop reference built for the people who actually work with valuation models every day—assessors, AVM architects, CAMA modelers, review appraisers, assessment leaders, VAB members, and consultants.

101 Key Terms for Valuation Modeling: A Practical Desktop Reference for Mass Appraisal, CAMA, and AVM Practitioners

Each of the 101 core terms follows a clear three-part structure:

·        Definition

·        Application in Valuation Modeling

·        Practitioner’s Corner

Closely related concepts appear as split entries for quick comparison. The book also includes specialized appendices with VAB & courtroom defense scripts, forensic audit terms, proprietary diagnostics, and real estate finance terms—plus a full A–Z master index for fast lookup.

This one is designed to stay on your desk, not collect dust on a shelf.

Available now on Amazon (Kindle, Paperback, and Hardcover) and as a PDF on Payhip.

All proceeds support charities, including Save the Children.

Amazon: https://www.amazon.com/dp/B0HJ4711H8

Payhip (PDF download): https://payhip.com/b/6KT2Z

Thank you for the continued support.

Sid

#MassAppraisal #CAMA #AVM #ValuationModeling #Assessment #PropertyTax

Tomorrow, September 9th: The Official Release of 101 Key Terms for Valuation Modeling

In Computer-Assisted Mass Appraisal (CAMA) and Automated Valuation Modeling (AVM), precision isn't just an academic pursuit—it is a forensic necessity. When appraisers, software architects, assessment officials, and tax appeal experts speak different dialects, valuation models break, tax rolls become vulnerable, and appeals drag on unnecessarily.

Tomorrow, that ambiguity ends.

I am officially releasing my newest ~400-page (Paperback) canonized desk reference:

101 Key Terms for Valuation Modeling: A Practical Desktop Reference for Mass Appraisal, CAMA, and AVM Practitioners

Built to stay on your desk rather than collect dust on a shelf, this compendium bridges complex econometric theory with real-world roll development and defense.

Each of the 101 primary terms follows a consistent three-part structure:

·  Definition — a concise, authoritative explanation

·  Application in Valuation Modeling — how the concept operates inside CAMA and AVM systems

·  Practitioner’s Corner — actionable guidance, common pitfalls, and defense-oriented insights

Packed with twelve master thematic categories, comparative split entries (A/B/C), three specialized back-matter appendices (including forensic audit protocols and cross-examination scripts), and a Master A–Z Index, this book provides the exact vocabulary required to build, audit, and defend robust valuation models.

Available tomorrow, September 9^th, in Kindle, Paperback, and Hardcover on Amazon and as a PDF via Payhip.

As always, author royalties from my books support charitable organizations, including Save the Children.

#ValuationModeling #MassAppraisal #CAMA #AVM #Econometrics #PropertyTax #Assessment #RealEstateValuation #TaxAppeal #SaveTheChildren

Long Weekend 50%-off Charity Flash Sale: 5 Books, 1 Cause!

 For this weekend only, we’re bringing back our 50%-off Charity PDF Download Event on Payhip! Whether you’re looking to master advanced valuation modeling, streamline assessment governance, or dive into non-valuation work, 100% of the proceeds from this campaign go directly to support our charitable cause. Download any (or all!) of these five featured titles as instant PDFs and support a great cause while expanding your library:

1.   Forensic Valuation Modeling: Fixing Costly Errors, Bridging Missing Links 

    Link: https://payhip.com/b/VXhb2

2. Challenging Your Property Assessment: The Art of the Rebuttal (A Comprehensive Guide to Winning Property Tax Appeals)

Link: https://payhip.com/b/01uD3

3.   The Pensionado Path: A Comprehensive Exploratory Guide to Affordable Retirement in Latin America

    Link: https://payhip.com/b/Rsa7w

4.   The Quantitative Investor: Mastering Data-Driven Strategies for Optimal Asset Allocation 

    Link: https://payhip.com/b/VWxul

5.   The Quantitative Country Analyst: A Data-Driven Guide to Global Mobility

    Link: https://payhip.com/b/OK2NM

Coupon Code: CHARITY50

Make an Impact: Every download directly funds our weekend charitable initiative!

Campaign ends Monday at midnight!

If you’ve been meaning to pick them up — or know someone who could benefit — now is a good time.

Thank you for your continued support, advocacy, and dedication to raising the standard of our valuation modeling industry while making a real difference.

Long-Weekend 50%-off Charity Flash Sale: 5 Books, 1 Cause!

For this weekend only, we’re bringing back our 50%-off Charity PDF Download Event on Payhip! Whether you’re looking to master advanced valuation modeling, streamline assessment governance, or dive into non-valuation work, 100% of the proceeds from this campaign go directly to support our charitable cause.

Download any (or all!) of these five featured titles as instant PDFs and support a great cause while expanding your library:

 

1.   Forensic Valuation Modeling: Fixing Costly Errors, Bridging Missing Links (Building More Defensible Models and Achieving BLUE Status) Link: https://payhip.com/b/VXhb2

2. Challenging Your Property Assessment: The Art of the Rebuttal (A Comprehensive Guide to Winning Property Tax Appeals)

Link: https://payhip.com/b/01uD3

3.   The Quantitative Country Analyst: A Data-Driven Guide to Global Mobility

    Link: https://payhip.com/b/OK2NM

4.   The Pensionado Path: A Comprehensive Exploratory Guide to Affordable Retirement in Latin America

    Link: https://payhip.com/b/Rsa7w

5.   The Quantitative Investor: Mastering Data-Driven Strategies for Optimal Asset Allocation

    Link: https://payhip.com/b/VWxul

Coupon Code: CHARITY50

Make an Impact: Every download directly funds our weekend charitable initiative!

Campaign ends Monday at midnight!

If you’ve been meaning to pick them up — or know someone who could benefit — now is a good time.

Thank you for your continued support, advocacy, and dedication to raising the standard of our valuation modeling industry while making a real difference.