This notebook describes concentration among new-car dealerships in Ohio.
One question to have in mind during all of this: What is HHI actually telling us? Espeically in a highly differentiated product market with strong preferences for types of products.
This figure describes statewide inside shares for the top dealer groups in Ohio, from 2005-2019. The largest dealer groups have 1-2% of statewide share, except for Ganley, who has risen to over 5% in later years. The most prominent national group in the state, Penske, was the 25th largest dealer group in 2020 with 0.8% share.
At the state level, concentration is very low. However, HHI nearly doubled from 2005 to 2018. HHI defined at the Dealer Group level (e.g. Ganley Auto group as opposed to Ganley Chevrolet) is over 3x that of the HHI defined at the dealership level, and increased slightly more (in pct terms) over the time period.
The next figures look at HHI, where the market is defined as a DMA. Note that Cincinnati and Toledo have dealers in Kentucky/Michigan, so those numbers are less accurate. Concentration is substantially higher when defined at the Dealer Group level. [Note: the axes are different!!]