Lansing Assessment Fairness Is the City of Lansing assessing its cheapest homes above the legal level?

Methodology, scope, and how to reproduce this

This tool exists so the assessment-fairness test can be checked by anyone. Every figure below comes from a public government record that any resident can request again and re-run.

Not legal or tax advice

This is an independent analysis of public records. It is not legal advice, tax advice, an appraisal, or the City's official assessment. An assessment ratio above the legal level, or a high composite score, shown here is an estimate and does not mean the City of Lansing, Ingham County, the Michigan State Tax Commission, or any other body agrees with it or will change an assessment or take any action. The only ways to formally contest an assessment are the local March Board of Review and then the Michigan Tax Tribunal, each with its own statutory deadline. Nothing here creates any obligation on any government body to act.

Scope: which homes are covered

The City of Lansing spans three counties. This tool covers only the parts of the City assessed within Ingham County (parcels in the City of Lansing assessing unit, parcel prefix 33-01). The smaller parts of the City that fall in Eaton and Clinton counties are assessed by other offices, were not part of the record used here, and are not yet included. Adding them would require a City of Lansing Assessor export of the whole-City roll: the City assessor sets and holds the assessed values and sales for the entire City, including the Eaton and Clinton portions. The public Eaton and Clinton county GIS portals were checked at the field level and do not publish the recorded-sale data the ratio needs, so they are not a substitute for that record.

The source record

All parcel, valuation, and sales figures come from the Ingham County Department of Equalization 2025 assessment roll, released as a Michigan Freedom of Information Act response, reference W061193-031426 (BS&A export, assessment year 2025). Any member of the public can submit the same FOIA request to Ingham County Equalization and receive the identical parcel master and sales (L-4260) file used here. The export was created 2025-05-23 (assessment year 2025); the map uses arm's-length sales from 2020-01-01 onward. Millage rates are from the Ingham County 2025 Apportionment Report. An independent University of Chicago analysis (the Property Tax Fairness Project) also finds Ingham County's residential assessments regressive; that study is county-wide and rates Ingham below the statewide average, whereas this map is City-of-Lansing-specific, where the pattern is sharper.

The legal level

Michigan law (MCL 211.27a) sets a property's State Equalized Value (SEV) at 50% of its true cash (market) value. So a fair assessment ratio is SEV / market value = 0.50. A ratio of 1.00 means a home is assessed at 100% of its market value, which is twice the legal level. An assessment ratio above 0.50 means the home is assessed above what the law allows.

The map: SEV vs. each home's own sale

The map colours H3 hexagons by the assessment ratio of the homes inside them, computed exactly as in the underlying analysis:

• Take every arm's-length sale (is_arms_length = 1) of ≥ $10,000 since 2020-01-01; keep each parcel's most recent such sale.
• Ratio = SEV / that sale price (2025 SEV).
• Universe: parcels with prop_city = 'LANSING' and SEV > 0, which is 7,696 City-of-Lansing arm's-length sales, matching the published brief. (No property-class filter is applied; that is what reproduces the 7,696 figure. The map itself can place the 6,683 of those that fall in the City of Lansing assessing unit, parcel prefix 33-01, and have parcel geometry; the remainder carry a Lansing mailing city but sit in adjacent assessing units.)
• Hexes with fewer than 10 sale-backed homes are greyed and their numbers withheld, a privacy and noise guard. The map shows area patterns, not "this house at this address"; owner names and per-parcel addresses never appear on the map.
• No time adjustment is applied: each sale is compared to the 2025 SEV regardless of when it occurred, so a single parcel's ratio is distorted where the gap between its sale and the 2025 assessment is large, or where the home was significantly improved after the sale. Aggregating thousands of sales limits the effect of any one parcel but does not remove a market-wide drift over the period.

On this 7,696-sale City universe, the published analysis finds the bottom decile (cheapest tenth of homes) assessed at 126% of market value, with 95.7% of those homes over the legal level. The coefficient of dispersion (COD) and price-related differential (PRD) are reported on residential-class City sales, the class the professional standard is written for: City of Lansing COD 28.75, PRD 1.33. The Ingham county-wide figures (COD 36.59, PRD 1.341, all property classes) are larger and are shown only for contrast, never as City figures. COD measures how scattered assessments are around the typical level; the IAAO Standard on Ratio Studies sets the residential COD bar at 15 or below, and a PRD above about 1.03 indicates the system leans against lower-value homes.

The other map layers

• Dispersion (COD) is the coefficient of dispersion of the assessment ratios within an area: the average absolute deviation from the median ratio, as a percent of the median. It measures how uniform (or arbitrary) assessments are. The IAAO professional standard for single-family residential is 15 or below.
• Estimated $ excess / area sums, over the sale-backed homes in a hex, an estimated annual over-payment of max(0, SEV − 0.5 × sale price) × millage at the City of Lansing / Lansing-schools homestead or non-homestead rate. It is the post-uncapping figure (what a recent or next buyer pays; see Proposal A below) and is an estimate, not a bill.
• Regressivity is, within a hex, the median ratio of the cheaper half of homes minus the median ratio of the pricier half. A positive number means the cheaper homes carry the higher assessments.
• Race (non-white and Black share) is US Census ACS 2022 5-year table B03002; ALICE is the United Way of Michigan ALICE share of households below the household survival budget; median household income is US Census ACS 2022 5-year table B19013. All are public tract-level figures joined to a hex through its dominant tract.

Composite over-assessment burden index

The composite is a single 0 to 100 score per area that answers one question: where is over-assessment both worst and landing on the households least able to absorb it? Each component is min-max normalised across the shown hexes and combined with fixed weights:

• 35% over-assessment magnitude (median assessment ratio)
• 25% assessment dispersion (COD)
• 20% within-area regressivity (cheaper-half minus pricier-half ratio)
• 20% household vulnerability (ALICE rate)

The composite is a constructed, weighted estimate, not an official or legal measure. The weights are a transparent editorial choice, stated here so they can be checked or changed; every component is also available as its own map layer. A high score is not a finding that any law has been broken or that any body must act.

Homes that went through tax foreclosure were over-assessed

Toggle "Tax-foreclosed homes 2024-25" on the map to see the City-of-Lansing homes that went through the Ingham County Treasurer's 2024 and 2025 tax-foreclosure auctions. Joining those auction outcomes to the 2025 assessment roll: of the 59 Lansing homes that sold at auction with a usable price, 57 (about 97%) had a 2025 SEV above the 50% legal level relative to the price they sold for, and 41 (about 70%) were assessed for more than the entire price the home actually fetched. The median ratio is about 135%, close to the 127% A-12 found for its hand-checked subset and to the bottom-decile pattern on the map. A further 8 parcels found no buyer at either auction and went to the county Land Bank.

Method and limits: auction parcels were read from the Ingham County Treasurer "Bids Won By Lot" PDFs (two have a text layer; two were scanned and recovered with OCR). Each parcel id is matched to the Ingham FOIA parcel master, and the 2025 SEV is taken from that authoritative record, so an OCR-garbled id simply drops out; the only auction-sourced number is the winning bid. The nine parcels independently hand-verified in the A-12 brief override the extraction. The published companion article reports only those nine hand-checked cases; this map applies the same test to every City-of-Lansing home in the 2024 and 2025 auction results (the larger set shown here), and the direction is the same. Auction prices are distressed-sale prices and understate market value, so the ratios are an upper estimate of over-assessment relative to true market value; the direction of the finding (the foreclosed homes were over-assessed) is robust to that, but the exact ratios are estimates. This shows the foreclosed homes were over-assessed; it does not by itself prove that over-assessment caused the foreclosures, which may be a cause or a symptom of the same financial distress. This is not a finding that any body broke a law or must act.

The checker: SEV vs. comparable sales

The "Check a home" view answers a different, narrower question: for one home, is its SEV out of line with recent arm's-length sales of similar nearby homes? It looks only at residential parcels and finds up to five comparable sales (same property class, within 25% square footage, within 20 years, same city, last 18 months). If fewer than three are found it widens the search (40% size, 35 years, county-wide, last 24 months); if still fewer than three it reports that it could not estimate the home rather than guess. It takes the median of those comparable sale prices as the market estimate and reports SEV / that estimate; the sale windows are measured as of May 2026, and the result card shows how many comparable sales it used and a confidence level. Because it averages against the wider market, it is deliberately conservative and will often read closer to 0.50 than the map's own-sale measure. It is an estimate, not the City's official value. The two views are complementary, not contradictory.

Proposal A: who actually pays the gap

Over-assessment is on the SEV. Under Michigan's Proposal A, a home's taxable value is capped while the same owner holds it, so a long-tenured owner whose taxable value sits below the inflated SEV may not pay the full over-assessment yet, but it is realised in full when the home next sells and the taxable value "uncaps" to the SEV. A recent buyer pays it from the first bill. Lansing also has the lowest taxable-value-to-SEV ratio of any major jurisdiction in the county, so its owners have less Proposal A cushion and realise more of any over-assessment as an actual bill. The estimated-excess figures use the post-uncapping amount. Do not read the map as "every owner overpays this much every year."

Reproduce it

• Request FOIA W061193-031426 (or an equivalent current parcel + sales export) from Ingham County Equalization.
• Run the ratio query above (it is stated in full so the count and the decile figures can be checked exactly).
• The build scripts that produced these files are published alongside the site (scripts/): the hex layer, the demographic and income join, the composite, and the per-home checker.