Market statistics don't match across sources/MLS

Market statistics don't match across sources/MLS

Why doesn’t the number on a Domus dashboard match another report (even one from the MLS)?

This is a common question, and it’s an important one. There are several reasons this can happen.
In most cases, the differences are due to filter mismatches—such as selecting different time frames, property statuses, or other criteria across platforms. But there are other factors too, including data cleansing, metric definitions, and data sources.

Understanding the Causes of Discrepancies

Here are the most common reasons for mismatched numbers:

Different Filter Settings

This is the most common reason for mismatches. Make sure:
  1. The time periods match exactly.
  2. You’re using the same property statuses (e.g., Active, Closed).
  3. Filters such as price range, property type, and geography are applied consistently.

Data Cleansing and Standardization

Domus applies rigorous data quality checks to ensure reliable reporting. As part of our process, we may correct or exclude bad or inconsistent data. Examples include:
  1. Clearly incorrect values, such as US postal codes with fewer than 5 digits or placeholder codes like 99999 or 88888, etc.
  2. Geographic corrections, such as assigning the correct city or county when fields contain vague or non-standard entries like "Other."
These adjustments and others help ensure that our dashboards reflect cleaner, more consistent data—but they may cause slight differences compared to raw MLS exports.

Different Metric Definitions

Some metrics are defined differently depending on the source. For example, “Days on Market” is a metric that can vary significantly due to differing rules about when counting starts or stops.

Different Processing Rules

Even when metrics have the same name and appear to be measuring the same thing, the way they are calculated and when they are timestamped can vary significantly between systems. These differences in processing logic can lead to confusing discrepancies.

A good example is Active Inventory.

  • In many third-party systems, inventory is calculated based on a single snapshot in time—often on the day the data was last pulled or updated.
  • This means that a report labeled “March” may actually reflect the active listings as of April 10th, if that’s the date the data was refreshed.
  • In contrast, Domus uses proprietary data processing that captures end-of-month inventory, giving a more accurate reflection of what was active at the close of March, not weeks later. 

This difference in timing can significantly affect the reported number, especially in fast-moving markets where inventory can shift rapidly.

Different Data Sources
Domus dashboards use MLS data directly. However, if you’re comparing our numbers to those from a third-party aggregator, especially those who may not be licensed through the MLS, you may see differences. Aggregators often receive data differently or apply their own processing rules.

How to Investigate Further

If you're comparing Domus data to MLS data and you can view the individual listings used in the MLS calculation, start by reviewing those listings.  Then, head to our member-only Market Insights dashboard, where you can drill-through the listings behind each calculation. This gives you full transparency and allows you to compare exactly which listings are included in each dataset.

If you’re comparing our data to a third-party report, remember: Unless the other vendor can show you exactly which listings they used, there’s no way to accurately audit their calculations. We always caution against relying on data that can't be traced to its source.

Still Need Help?

If you’ve checked all the above and still can’t find the discrepancy—or if the reason remains unclear—please reach out to your MLS support team. They can help investigate further.


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