Local data guides
Understand the inputs, compare scenarios and check the limits behind a result.
These guides explain practical workflows using illustrative numbers. Start with the input method, then use the calculators with your own measurements or records.
How to Compare US Counties Without Misreading the Data
Understand geography, source years, population change, density, and vacancy.
Read guide →A Source Checklist for Comparing Local Population and Housing Data
Match geography, year, units and definitions before calculating local growth, density or housing vacancy; preserve a reproducible source note.
Read guide →