Wisconsin: A Blueprint For More Workers, by Ike Brannon and Andrew Hanson, visiting fellows at the Badger Institute.
From the Conclusion:
"Wisconsin’s historically low unemployment rate has led some to fear that a shortage of workers may constrain the state’s future economic growth. The state’s labor force participation rate is significantly lower than where it was the last time unemployment was this low, something that is true for the rest of the country as well. ..."Also at Badger Institute, an interactive map of Labor Force Participation Rate By County 2017.