A Combined Statistical Area (CSA) is defined by the U.S. Census Bureau as a combination of several adjacent Metropolitan Statistical Areas (MSAs) or Micropolitan Statistical Areas (μSAs), or a mix of the two, which are linked by economic ties.
A Core-Based Statistical Area associated with at least one urban cluster having a population of at least 10,000 but less than 50,000 inhabitants. It includes the central county or counties containing the core, plus adjacent outlying counties highly integrated economically and socially.
