Create Arlington Heights PTAXSIM Counterfactual Vignette

[ccao-jardine]

Research goal

This PTAXSIM counterfactual answers the policy question, "if the PINs comprising the Arlington Heights racetrack had had their taxable value frozen in 2009, how would this have affected tax bills from 2009 through 2024?" The results of this study can help legislators contextualize the potential impact of proposed legislation that would freeze the taxable EAV on the sites of proposed mega-projects.

The goal of this issue is to create a vignette that:

• answers the above research question as a case study, and
• parameterizes clear variables for the case study's PINs, municipality, frozen year & assessment stage, and impact study years, so that these are easier to swap out in future studies.

Study parameters

The municipality for this case study is VILLAGE OF ARLINGTON HEIGHTS (030020000).

The study PINs (PINs to be frozen that comprise the Arlington Heights Race Track) are listed below. Some of PINs were divided in tax year 2024, meaning several PINs listed do not have any associated data after 2023, while others will have data only in 2024. To ensure the data is complete and accurate for all study years, make sure to query all of the following PINs:

PINs existing all years:

• 02-26-201-010-0000
• 02-23-403-003-0000
• 02-25-100-005-0000

PINs existing 2006-2023:

• 02-25-202-008-0000
• 02-24-303-007-0000

New PINs in 2024:

• 02-25-202-011-0000
• 02-25-202-012-0000
• 02-24-303-009-0000
• 02-24-303-010-0000

The frozen year is 2009, and the frozen assessment stage is av_clerk (or av_final, if so named).

Finally, the impact study years (where we are evaluating the impact) are 2009 through 2024.

Methods

We will construct a counterfactual that has one simple modification: for the study PINs, their final AVs in every Tax Year from 2010 onward are replaced with the final AVs from 2009.

Specifically, let's evaluate the impact on the tax bills of:

• the median home (class 2)
• the median commercial property (class 5)
• the study PINs themselves

Results communication

The goal is to quantify how tax bills would have been affected in the counterfactual scenario versus reality, and to quantify that for homes, for commercial properties, and for the study PINs. We should also quantify the impact to the municipality.

Note that tax bills fluctuate for a variety of reasons, especially during the time period of 2009-2024. It'll probably be helpful to include context like the median AVs for each of these three groups too so that it's easier to spot if tax bills are fluctuating more or less than AV fluctuations.

Results 1: Impact on Homeowners and Commercial Property Owners

For the median home and median commercial property, each should have two graphs:

• Median AV, per tax year, with one line for "true" and one line for "counterfactual". (These lines will overlap for the "Median Home" and "Median Commercial Property" because they aren't being adjusted in the counterfactual.)
• Median tax bill, per Tax Year, with one line for 'true" and one line for "counterfactual."

Optional: it could be helpful to also show the summed AV and summed tax bills for class 2 and class 5, to quantify the total tax shift from the study PINs to all homeowners and commercial properties. This should be calculated per Tax Year, and then summed across all tax years to calculate the total shift.

Results 2: Impact on study PINs

Here we quantify the effect on the study PINs.

For the study PINs group, let's do:

• Sum AV, per tax year, with one line for "true" and one line for "counterfactual". (This will show the total AV of all the study PINs in the counterfactual.)
• Sum tax bill, per Tax Year, with one line for 'true" and one line for "counterfactual." (This will show the total tax bill for the study PINs.)

Results 3: Impact on the case study municipality

We should also examine the impact on the municipal taxing agency. If Arlington Heights has TIF district(s), its TIF revenue could be affected by the counterfactual freezing of the AV.

Here, let's visualize, per Tax Year, the total TIF revenue for all TIFs in the study municipality, for each Tax Year. Then, we should calculate the total TIF revenue change across all Tax Years.

Time permitting

Your intro could visualize the racetrack PINs in the whole map of Arlington Heights, similar to how we map the area in PTAXSIM's TIF vignette.

Schedule

If this is someone new to PTAXSIM, great! Here's a suggested schedule:

• Week 1: Complete your onboarding issue, including determining weekly check-ins, and have a project kickoff with your project lead. This may include reading about the proposed legislation for this particular case study.
• Week 2: Install PTAXSIM and work your way through the Appeals Vignette to understand how it works.
• Week 3: We'll teach you about github and creating a development branch. This week you'll create and commit to your development branch, with the start of your new Arlington Heights Vignette.
• Weeks 4 onward: Meet with your project lead weekly. Our expectation is that you are regularly committing work that demonstrate progress toward the final product. Ask questions throughout! Work with your project lead so that you create a pull request and request review with sufficient time for your code to be reviewed. You might also meet with the Policy team.
• Week 9: Your code is reviewed and merged in!
• Week 10: Wrap-up tasks, including your intern memo if an intern.