Chicagoans aren’t afraid to talk back to the taxman.

According to TurboAppeal, 99,659 tax appeals for single-family homes were filed last year in Cook County, Ill., the second-most populous county in the U.S. (behind Los Angeles). Of those appeals, 60,411, or about 60%, led to a reduced tax bill. In all, the county refunded more than $87 million in appealed property taxes in 2014.

“There’s...