Missing data for Neighborhoods or Tracts
If there were less than a few dozen RESALES of SFR houses (EXCLUDE all new home sales) in any of the 3 prior years, that would explain why there is no data for that tract.
Here's how the Micro Market data works in our system:
In order to get the dead-accurate data needed for TA, we ONLY use REPEAT home sales data. We need at least a few dozen REPEAT home sales in each tract, in EACH consecutive year before we can begin to do anything with the data.
By tracking RESALES of the same specific properties over time, combined with a statistically valid sample size of OTHER REPEAT RESALES in that same geography, we can compute what the market is doing on a more granular basis.
Because of small sample size limitations, I want to point out that the Micro Market data does not have the same accuracy as the METRO level data.
That's why we don't/can't do a full blown "TA Analysis" that includes Wealth Phases, TAPS Sliders, etc on any geography smaller than the city/MSA level.
Micro Market data does not have enough REPEAT transactions for the kind of statistical accuracy required for T.A.P.S. and other TA studies. Also, Micro Markets are NOT a "Market" - they are small pieces of the Metro Market - and will generally move in-line with the Metro Market over time.
You should primarily use Micro Market data to compare RELATIVE differences between zip codes INSIDE each Metro level.
In addition to the greater accuracy and reliability, Metro level data is also much faster to respond to major changes occurring in a market over a short time period.
In other words - if a Market takes a quick, major dive or starts shooting to the moon, it will be picked up much earlier at the Metro level when compared to the Micro Market levels.
The bottom line is: We need to have a valid sample size (ideally at least a few dozen) REPEAT home sales EVERY YEAR in a tract - for at least 3 years - before the data can produce acceptable results.
The more years and the more transactions IN each year for a given tract, the more reliable the results.