Map of every home in Massachusetts by assessed value (Boston: 2014, house)

[Brave Stranger]

Really nice map.

[porterhouse]

Nice idea, however highly inaccurate for anything beyond general observations.

[GeoffD]

Originally Posted by porterhouse

Nice idea, however highly inaccurate for anything beyond general observations.

It's using actual assessor data. The data is a year+ old but there is nothing at all inaccurate about it. I zoomed in on my neighborhood. The appraisals all match the town database.

What it shows is how socioeconomically segregated Massachusetts is. It's what happens when you have public school systems that are funded by individual towns.

[Shrewsburried]

Originally Posted by GeoffD

It's using actual assessor data. The data is a year+ old but there is nothing at all inaccurate about it. I zoomed in on my neighborhood. The appraisals all match the town database.

What it shows is how socioeconomically segregated Massachusetts is. It's what happens when you have public school systems that are funded by individual towns.

Agreed. The only minor critique is the lag and the reality that some towns with lower rates are more likely to have high assessments (e.g., Shrewsbury) and vice versa. It does not, as you suggest, undermine the overall trends.

[porterhouse]

Originally Posted by GeoffD

It's using actual assessor data. The data is a year+ old but there is nothing at all inaccurate about it. I zoomed in on my neighborhood. The appraisals all match the town database

Just looking at Boston and Cambridge, every property I have owned or currently own is misclassified (sometimes by several categories), as are the other homes in the neighborhood. The data it is either not reflective of actual market values (based on sales), quite outdated, or a combination of both. YMMV may vary for other cities and it is entirely possible this is more accurate at a granular level for the burbs.

[yellowstatus]

Really cool link!

From a data perspective, people's critiques come off as minor complaining. What alternative real-life data set are you proposing instead? Tax assessment real estate data is as good as it gets. Real estate sales are public record, but only a small fraction of homes are sold annually. You'd need to build a valuation model for the rest. On site professional assessment like those done by mortgage companies are excellent, but completely impractical for data at this scale. I would love for a God from above to enlighten me with the true home values, but tax assessor data is a great place to start for mere mortals : )

[masshawk]

Westwood was a surprise to me. I considered it an affluent town, but not among the super fancy W towns. By this map it's just as purple/blue as Wellesley, Wayland, and Winchester.

[G-fused]

Originally Posted by porterhouse

Just looking at Boston and Cambridge, every property I have owned or currently own is misclassified (sometimes by several categories), as are the other homes in the neighborhood. The data it is either not reflective of actual market values (based on sales), quite outdated, or a combination of both. YMMV may vary for other cities and it is entirely possible this is more accurate at a granular level for the burbs.

It is tax assessed data, not market value.

[tysmith95]

One map issue for closer in areas of Somerville/Cambridge/Boston is that it does not do a good job separating triple deckers. For example you'll get data that's split up into 3 different condos but the next house over will have a single owner and be considered one "home".

[CaseyB]

Originally Posted by G-fused

It is tax assessed data, not market value.

Yes, it's assessed and every town does their assessments differently depending on their tax rates.