HomeMy WebLinkAbout9/8/2026 - Revenue Projection Process and Forecasting Model. ,
Revenue Projection Process
and Forecasting Model
Board of Supervisors Work Session
September 8, 2026
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Roanoke County Revenue Projections
• Analysis by Finance and Management Services Staff
• Judgmental forecasting based on trends
• Dashboards
• Different models for different revenue sources
• Focus analysis efforts on harder to predict revenues
• Approximately 135 different revenue sources
• Virginia Finance Network
• Revenue team approach
Revenue Forecasting Process
• Analyze prior year revenue trends and monitor monthly revenues
• Review economic indicators
• Consult Finance Network resources
• Revenue Team meetings (December -February)
• Analyze possible state code changes
• Real Estate and Personal Property Assessments
• Present preliminary revenue outlook to the Board of Supervisors
• Make final adjustments before Proposed Budget
FY 2027 General Government
Revenue Collection Summary
Category Date(s)/Period of Collection
Real Estate 1st Half in December (CY 2026), 2 nd Half in June (CY 2027)*
Personal Property Receive in May-June, billed annually
Sales Tax Receive monthly, 2 months delay
Business License Receive in February-March annually
Current Public Service Receive in November -December annually Corp
Meals Receive monthly, 1 month delay
Hotel/Motel Tax Receive quarterly, some received monthly
* 1st Half of Real Estate based on CY 2026 Assessment, 2 nd Half based on CY 2027 Assessment finalized in January 2027
% of Total
Budget
50.5%
17.2%
5.9%
3.4%
2.9%
2.4%
0.9%
Current Forecasting Methods
• Use of Excel statistical tools and judgmental forecasting methods
• 2 month and 12 month moving averages for revenues collected at
regular monthly intervals
• Perform regular monthly analysis and update budget projections
throughout the year informing revenue forecasting for upcoming year
• Use of Al tools for revenue forecasting including ChatGPT, Perplexity,
and Claude
Virginia Finance Network
• Began during COVID to share information related to CARES Act and
ARPA
• Information shared from various organizations including:
• ICMA
• Virginia Association of Counties
• Virginia Municipal League
• GFOA and VGFOA
• Networking between local governments in Virginia on common issues
Revenue Team
Departments Represented
Revenue Team Strengths
• Obtain input from revenue generating departments
• Subject matter experts on various aspects of the local economy and
items that affect revenue collection
• Broad perspectives on economic trends and legislative impacts
• Consensus approach to revenue budget
• Considerations of Board of Supervisors preferences
Roanoke County Results
• Comparing original budgeted revenues to actual revenues, Roanoke
County has done well compared to other localities in Virginia
• Roanoke County took a very conservative approach during COVID and
the following high inflation years
• Revenue growth is slowing and returning to normal
• While revenue growth is slowing, expenditure growth continues at a
higher level
Caleb Eng
Finance Intern -Budget
Division
I grew up in Roanoke, VA attending
Faith Christian School.
I now study at Northwestern
University where I major in
Economics and Mathematical
Methods in the Social Sciences. I
also minor in Math and am working
towards a certificate in Financial
Economics through the Kellogg
School of Business.
I am interested in pursuing my PhD in
Economics.
I also serve as a research assistant to
Robert J. Gordon, a well-respected
macroeconomist.
Content Overview
• As an intern, I have been focusing on projecting the revenues from
year to year
• This presentation details some of the challenges involved with doing
so as well as some of the methods for forecasting
• These methods and challenges were all considered in my revenue
forecasting model, which I have created over the course of this
internship
Challenges with Revenue
Forecasting
• This graph displays one
method of projecting the 315
revenue.
• The main point is that
projections are inherently
uncertain, we can do the
best we can to try to
establish a baseline
estimate, but any forecast
carries uncertainty.·
295
275
255
235
215
195
Historical and Projected Revenue ($M)
2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029
95% Prediction Interval 80% Prediction Interval 50% Prediction Interval
• To illustrate how wide an
accurate forecast can be:
• For 2027,
• Forecast Value: 287.0M
• 50% chance: 282.7 -291.3M
• 80% chance: 279.0 -295.3M
• 95% chance: 274.8 -299.8M
• Note: this is just one
projection method,
economic indicators suggest
we will likely be below the
forecast value.
Revenue Growth Rates (%) Real and Nominal
2026 2027
95% Prediction Interval 80% Prediction Interval 50% Prediction Interval
Inflation Also Presents a Challenge
• Historically, our budget growth has been driven very heavily by
inflation, however in FY 2022 & FY 2023 we had a period -of unusually
high inflation followed by FY 2024 & FY 2025 which saw high growth
in real dollars.
• The unusually high real growth rates over the past few years could be
reversed. 2026 is evidence of this.
• Some real growth is simply delayed inflation growth (partially
attributable to real estate assessment timing)
Real Growth Rate of Budget (%)
8
(growth rate without inflation; adjusted for budget code changes; log growth)
7
6
5
1
0
2017 2019 2020 2021 2023 2024 2025 2026
-1
-2
■Real
8
7
6
5
~ 4
QI ..
Ill
~ 3
i
0
~ 2
1
0
-1
-2
2017
Growth Rate of Budget {%)
(adjusted for budget code changes; log growth}
2019 2020 2021 2023
■ Real ■ Nominal
2024 2025 2026
8
7
6
5
1
0
-1
-2
I
2017
Growth Rate of Budget (%) and Inflation (%, PCE)
(adjusted for budget code changes; log growth)
2019 2020 2021 2023 2024
■ Real ■ Nominal D Inflation
2025 2026
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General Methods for
Forecasting Revenue
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Method Overview
Over the course of my internship with Roanoke County, I have explored
a few primary methods for projecting the revenues. For funds that
exhibit semi-stable growth I consider the following:
• Average Historical Growth Rate (seen earlier)
• Moving Average Growth Rate
• Autoregression
• Exponential Smoothing
Historical Average Growth Rate
• Takes the whole average growth
rate of the budget, or budget
line-items and applies it forward.
• Pros:
• Good baseline
• Easy to calculate na·ive confidence
intervals
• Cons:
• Does not factor more current
information
Moving Average Growth Rate
• Takes some of the most recent
revenues and computes their
growth rates and applies it
forward
• Pros:
• captures trends
• Cons:
• trends reverse, 2026 is evidence
Autoregression
• Looks at the most recent growth
rate and moves it closer to the
average at a rate determined by
historical growth
• Pros:
• Considers recent and past
information
• Cons:
• Takes more data than we have to
be highly accurate
Exponential Smoothing
• Estimates a growth trend and
level by weighting more recent
information more heavily
• Pros:
• captures trends while still
accounting for the whole history
• Cons:
• trends reverse
Model Accuracy
Using an appropriate, predetermined, weighted average of methods for
FY 2025 and FY 2026 and correcting with only information that would
be available at the time we obtain the following:
FY Actual ($M) Forecast ($M) Error ($M) Error(%)
2025 266.0 268.6 2.6 0.97
2026 275.2 274.5 -0.7 -0.26
This is not a definitive range of plausible errors but should provide
context for how well the math can and cannot do.
Forecasting Real Estate
• It is very rare, but
sometimes we can use one
index to predict a budget
line-item
• Given assessment timing, it
25
20
15
is possible to use this fact to 10
project assessment values
and therefore revenue from 5
rea I estate tax
• This approach is still error
prone (average +/-2.01% on
assessments)
-5
-10
Case-Schiller Housing Price Index (Blue) vs Total
Assessment Value (Orange),% Growth Rates
2010 2012 2014 2016 2018 2020 2022 2024 2026
Questions &
Comments