No published figure on this site has needed a correction yet. That is not a claim of infallibility - it is the first thing this page will record when it happens. What it already records is the more useful list: analyses that were completed, checked, and then rejected.
Every one of the following was a finished result with a headline attached. Each was killed by its own data. They are published because a corrections page that is empty on day one tells you nothing about the standard being applied.
Rejected 2026-08-18
A first pass measured heat-pump share against free-text heating permits and found Lexington at 100% and Cambridge at 87%. Both figures were artifacts of record-keeping, not heating markets: those towns file fossil-fuel heating work under a fixed category label rather than a description, so a text search finds every heat pump and no boiler. Lexington's 84 gas permits carry exactly one distinct description string between them. Rather than drop the story we added an eligibility test and published the exclusions as part of the finding -- see the heat-pump article.
Rejected 2026-08-18
The 7x spread was a permit-mix artifact. In two of the towns, around 61% of the valuation-bearing 'kitchen' rows were electrical or plumbing sub-permits, versus 9% in the town at the other end. Comparing building permits to building permits, the spread collapses to 1.9x -- against 1.6x for roofing, which was supposed to be the control. Kitchens vary about as much as roofs do, which is the opposite of the headline.
Rejected 2026-08-18
Dropped on privacy, permanently. 88.5% of contractor-bearing permits name an individual rather than a firm, and the largest single filer in the solar data is a private person. No level of aggregation makes that safe to publish, so the contractor column is never article subject matter here.
Rejected 2026-08-18
The apparent 20% downward revision was measured across a window in which our own corpus went from 44,296 rows to 23,577 to 34,382 to 37,426, while sources were being lost and rebuilt. Every 'revision' was ours. Worth revisiting after roughly 90 days of uninterrupted snapshots on a stable source list.
None to date. When one is needed it will be appended here with a date, and the affected article will keep its URL and carry a note - corrections are never made silently.
Every article links the JSON file containing its own figures, so a disagreement can be made specific. Corrections go to [email protected].