Property Revaluation 501: Mapping & Color Coding Jersey City Home Sales by Assessment-Sales Ratio

This post is part of an ongoing series about property revaluation in Jersey City.  

I partnered with CivicJC to create an interactive map to help residents visualize 2015 property sales in Jersey City and their corresponding taxes. Recent property sales are informing because they are used as a proxy for market value when establishing the city’s annual equalization ratio.

Click here to enlarge the map in a new browser window.

How it works

Pin drops are color coded:

• Green = under assessed (ratio below 23.49)
• Red = Over assessed (ratio over 31.77)
• Black = Fairly assessed (ratio between 23.49-31.77)
  

Ratio ranges and qualification of “under”, “over”, or “fairly” assessed are based on the following:

• Jersey City’s 2016 equalization ratio is 27.63.
• The “common level range” is a plus or minus 15% range around the equalization ratio. Properties assessed above or below this range may qualify for re-assessment, per Chapter 123 Law. Specifically:
  • The upper limit of the common level range is 27.63 +15%, or 31.77. Properties above the upper limit are considered over-assessed and shown with red pin drops.
  • The lower limit of the common level range is 27.63 -15%, or 23.49. Properties below the lower limit are considered under-assessed and shown with green pin drops.

Methodology

This is how the map was made:

1. This is a Google map employing 4 layers. Layer 1 is the color-coded ward map and layers 2-4 are subsets of usable Class 2 property sales broken out by under, over-, or fair assessment categories.
2. The color-coded ward map is available on Jersey City’s open data portal.
3. 2015 property sales were downloaded from the NJ Assessments Records database.  We used calendar year sales for simplicity of demonstration. [Note: the NJ Division of Taxation and county tax boards use fiscal year sales (July 1 – June 30) as a sampling period to set the equalization ratio.  You can read more about the formal process of equalization here, excerpted from the NJ Tax Administrator’s Handbook available here.]
4. Data was filtered as follows:
   • Database Type: Current Owners/Asssmnt List
   • Step 2, County: Hudson
   • Step 3, District: Jersey City
   • Step 4, Search Format: Advanced Search
   • Step 5, Output Format: Excel
   • Advanced Search Options:
   • Class: 2….Residential Property (1-4 Family)
   • Date Range: 1/1/2015 – 12/31/2015

Once downloaded, the data was “scrubbed” to remove data that wasn’t appropriate for inclusion in the map. Specifically:

1. The map shows “usable” sales only, i.e. third-party transactions.  Note: non-usable sales transactions (e.g. sales between family members, sheriff’s sales) are defined by statute and listed here.
2. A total of 2,698 records were downloaded.
3. 1,156 records were coded “non-usable” sales by the city. These were removed from the map because they are not used to compute the citywide equalization ratio.
4. 56 records were coded “outlier” usable sales, assumed to be data entry errors, e.g. where a $1 sales is not coded as “non-usable”.
5. 1,486 sales were coded “usable” and non-outlier and these are the sales that appear in the map.
6. Usable sales were segmented based on ratio value. The “ratio” is a measure of the property’s assessed value to sales value.
   • Under-Assessed: Defined as having a ratio below 23.49
   • Fairly Assessed: Defined as having a ratio between 23.49 and 31.77
   • Over-Assessed: Defined as having a ratio above 31.77
   • To learn more about these ratios, and the mechanics that determine over-, under-, or fair assessment, read about Chapter 123 Law here.  You can also read my recent blog post, Property Revaluation 401: Tax Appeal Math (Chapter 123 Law).

#OpenData

This map is based on publicly available tax records.

• The data included in this map was downloaded from the NJ Records Assessment database.
• The 1/1/2015 through 12/31/2015 dataset downloaded from NJ Records Assessment database is available in CSV format here (2,698 records).
• The 2015 sales dataset, with Ward/City/State data added, is available in MS Excel format here (1,486 records).

If you notice errors or omissions in the map, or have questions, please leave a comment, or contact me at Brigid.DSouza@CivicParent.org, or contact me through my Facebook page.

In Case You Missed It…

The other posts in this series include:

• Property Revaluation 101: the Equalization Ratio
• Property Revaluation 201: Quantifying Tax Inequity (A Simple Example)
• Property Revaluation 301: Estimating Your Post-Revaluation Tax Bill
• Property Revaluation 401: Tax Appeal Math (Chapter 123 Law)