Operation of a taxi cab in Chicago requires a City-issued medallion. These medallions may be sold on the open market, with the City of Chicago recording the sale and change in ownership. This dataset shows such medallion transfers.

See https://www.cityofchicago.org/city/en/depts/bacp/supp_info/medallion_owner_information.html for more information about taxi medallions in Chicago.

See https://data.cityofchicago.org/d/tfm3-3j95 for the current Public Passenger Vehicle Licenses in Chicago. For taxis, the Public Vehicle Numbers will match between these datasets.

Chart of average sale prices by month.