Are abolished counties still included?
Yes. The 14 Census counties remain usable geographic units, even where county government or functions have changed.
What is the county GEOID for Boston-area county data?
Use 25025 if the observation covers Suffolk County. Boston city data has a different geographic scope.
Which counties contain Martha’s Vineyard and Nantucket?
Martha’s Vineyard is within Dukes County, GEOID 25007. Nantucket County is a separate unit, GEOID 25019.
How is Cape Cod represented?
Use Barnstable County, GEOID 25001, for county-level Cape Cod observations. The geometry uses the generalized Census shoreline.
Can I color Massachusetts towns?
This map selects counties. Use town boundaries for town-level observations or aggregate the observations before joining them to counties.
Why can Middlesex grow with net domestic losses?
Total population change includes international migration, births, deaths and adjustments in addition to moves within the United States.