*The MSA data in this chart covers of the following counties: Barry, Kent, Montcalm, and Ottawa.

**The 2000 CSA consists of the following counties: Allegan, Barry, Ionia, Kent, Ottawa, Muskegon, and Newaygo.

Data Source: Georgia State University, http://unionstats.gsu.edu/

• Because this dataset relies on small samples, a 3-year rolling average is used to estimate union membership
• Union data is available only for the 2000 configurations of the MSA and CSA.