Methodology

Sources

The index draws on two primary sources, and never on portal scraping or third-party estimates — every number traces to an actual lease or an actual advertised unit:

• Scattered-site (MLS). Rental listings that reached a leased status in the MLS systems covering our markets — MRED (Chicago) and RealTracs (Nashville) — accessed through our licensed data provider. These are individually listed rentals: condos, houses, and units in smaller buildings.
• Managed communities.A longitudinal panel of professionally managed apartment communities, snapshotted over time in Abode’s systems. Because we observe the same units month after month, this source carries both the advertised rent and the concession detail needed to compute net-effective rent — and supports the repeat-rent index below.

Effective rent — the headline

The Rent Index leads with net-effective rent: the advertised (asking) rent minus the value of concessions, such as one or two free months on a lease. It is the number that reflects closer to what a renter pays than asking rent alone. It is computed from advertised terms, not signed leases. When concessions are common, reporting asking rent alone overstates true rent — so we compute and headline the effective figure, and show asking rent beside it along with the concession spread.

We publish medians, not averages, so a handful of luxury or distressed units can’t skew the figure. Every cell is reported for the month the unit leased (scattered-site) or the snapshot month (managed).

Three views: scattered-site, managed, and combined

Scattered-site rentals and large managed communities are genuinely different markets and often move differently, so we publish all three views rather than hiding the difference inside one number:

• Scattered-site — individually listed MLS rentals.
• Managed communities — professionally managed apartment buildings, on a net-effective basis.
• All rentals — the two segments combined by housing-stock weight, described next. The segments are not yet deduplicated against each other; a community that also lists units on the MLS can appear in both.

The combined index — weighted to the housing stock

A naive combined number would be dominated by whichever source has more listings in a given month — not by the shape of the actual rental market. Instead, we weight the two segments by each metro’s share of renter households living in 1–4-unit vs. 5-or-more-unit buildings, from the U.S. Census American Community Survey (table B25032). Scattered-site rents are weighted to the 1–4-unit stock; managed rents to the 5-plus stock. Duplicate units appearing in both sources are reconciled so they aren’t double-counted.

Measuring change: the repeat-rent index

A median answers “what is rent.” It is a poor answer to “how much did rent move,” because the mix of units that lease changes month to month — a quiet month heavy on studios will drag the median down even if no landlord changed a price. To measure change cleanly we use a repeat-rent index: for every managed unit observed in two consecutive months we take the change in its own rent, average those (trimming outliers), and chain the result into an index — the rental analogue of the Case-Shiller repeat-sales method and Zillow’s ZORI. It is immune to shifts in which units happen to list. The index is anchored to real dollars so it still reads as a rent level.

The same-unit panel is deep enough for reliable month-over-month change now; year-over-year on the repeat-rent basis becomes available once a full year of panel history has accumulated. Until then, year-over-year is shown on the median basis and labeled as such.

Seasonal adjustment

Rents follow a strong, predictable within-year cycle — demand and prices peak in late spring and summer and trough in winter. A raw month-to-month change mixes that calendar effect with the real trend. We estimate multiplicative month-of-year factors on the combined effective series using the ratio-to-moving-average method (the seasonal core of the Census Bureau’s X-11) and publish a seasonally-adjusted read alongside the headline.

Seasonal adjustment is marked experimental while our price history is short (under about five years); the unadjusted series remains the published headline.

Reliability & revisions

• Small-sample suppression.Any cell (a neighborhood, bedroom count, and month) with fewer than 10 leased listings is withheld and shown as “—”. We would rather publish nothing than publish noise.
• Thin-sample flagging. Month-over-month and year-over-year changes computed on fewer than 20 leases that show extreme swings are flagged with a dagger (†): at small sample sizes, a few unusual listings can move the median more than the market did.
• Concession validation. Net-effective rent is only as good as the concession behind it, so we screen every managed unit before it enters the index: a net-effective rent above the asking rent or at or below zero is discarded, and any concession implying more than 35% off asking is capped at that ceiling as an implausible parse. In practice these guardrails move the published figures by less than a dollar — the effective-rent series is not sensitive to a handful of mis-read promotions — but they make the index provably immune to the worst data errors.
• Preliminary latest month, and revisions. Leases keep reporting for weeks after a month closes, so the most recent month is labeled preliminary. It may be revised — almost always upward — in the following release, then finalized. We label the newest print rather than present it as settled.
• Reporting lag and sample maturity.That lag is large and measurable, not a formality. On release day the newest month typically holds only a quarter to a third of the leases it will eventually contain, while every settled month sits near its market’s normal volume. In the current release: Chicago 614 of a typical 1,606 (38%); Nashville 54 of a typical 224 (24%). Publishing that partial month on its own would let a fraction of the sample drive the headline, so when a recent month falls below 60% of its market’s typical monthly sample we publish it on a sample-weighted three-month basis instead — the same rolling-window treatment thin neighborhoods already receive. The partial month still counts, in proportion to how much of it has reported. Settled months are never rewritten this way, and the as-reported figure is retained.
• Year-over-year compares like with like. The MLS series samples the same population each year, so its 12-month change is a straight comparison. The managed-community panel is not a fixed sample — it has grown several-fold over the past year as communities were added — so a whole-panel change would measure which buildings are tracked, not what rents did. Managed year-over-year is therefore reported on a same-communitybasis: only communities observed in both the current month and the same month a year earlier, with one observation per unit per month on each side, the construction real-estate operators know as “same-store.” The number of communities in the comparison is shown alongside the figure. Unit mix within a community can still shift; a unit-level match will replace this once a stable per-unit identifier is in place. The combined figure is the housing-stock-weighted average of the two segment changes, not a change in blended levels.
• One observation per unit per month. Managed-community rents are observed nightly. Each unit is reduced to a single observation per month before any median is taken, so a unit that sits on the market for weeks does not count more than one that leases in days.
• Partial months. The current, still-open calendar month is excluded until complete.
• Neighborhood boundaries. Listings are assigned to neighborhoods by geographic boundary — official community areas in Chicago, neighborhood boundaries in Nashville — not by the unreliable free-text neighborhood field in listing records.
• City vs. suburbs. Citywide figures cover the city proper only. Surrounding suburbs are published in a separate, clearly-labeled group and never blend into citywide statistics.

Release schedule

The index is refreshed monthly, early in the month — around the 7th — once the prior month has had time to report late leases. Each release updates the prior month and may finalize the month before it. The latest data and next-release date are noted at the top of every Rent Index page.

What it doesn’t measure

MLS sources do not disclose the final negotiated lease price for scattered-site rentals, so those figures reflect the asking rent of units that leased — a close proxy, not the signed number. (For managed communities we do observe concessions and report net-effective rent directly.) The index is informational and is not an appraisal, a guarantee of availability, or an offer of housing at any price.

Citing the index

Journalists and researchers are welcome to cite published figures with attribution: “Source: Abode Rent Index — abode.realestate/rent-index”. For data questions, chart files, historical series, or market commentary, contact [email protected].

Abode Real Estate is an equal housing opportunity brokerage. The index reports market pricing facts only.