Summary statistics of the Herfindahl-Hirschman Index (HHI) across US census tracts, measuring market concentration for different vehicle market dimensions. HHI values are computed per census tract based on dealers reachable within a 60-minute drive time isochrone, then summarized across tracts. Higher HHI values indicate greater market concentration (less diversity). Nine grouping-variable combinations are included: for each grouping variable (powertrain, vehicle type, price bin), HHI is computed over the other three variables (make, and the two remaining grouping variables).
Usage
data(hhi_local)Format
A tibble with 11 variables:
| Variable | Description |
group_var | Grouping variable: "powertrain", "vehicle_type", or "price_bin" |
group_level | Level of the grouping variable (e.g., "Gasoline", "Car", "$30k-$40k") |
hhi_var | Variable over which HHI is computed: "make", "powertrain", "vehicle_type", or "price_bin" |
listing_year | Year of the vehicle listing |
mean | Mean HHI across census tracts |
median | Median HHI across census tracts |
q25 | 25th percentile HHI across census tracts |
q75 | 75th percentile HHI across census tracts |
IQR | Interquartile range of HHI across census tracts |
upper | Upper whisker bound (q75 + 1.5 * IQR) |
lower | Lower whisker bound (q25 - 1.5 * IQR) |
Source
Computed from vehicle listings data from Marketcheck.
Details
Census-tract-level HHI values (before summarization) are available as parquet files on GitHub at https://github.com/vehicletrends/vehicletrends/releases/tag/data-v1.
Examples
data(hhi_local)
head(hhi_local)
#> # A tibble: 6 × 11
#> group_var group_level hhi_var listing_year mean median q25 q75 IQR
#> <chr> <chr> <chr> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
#> 1 powertrain Battery Elect… make 2025 0.228 0.192 0.136 0.265 0.129
#> 2 powertrain Battery Elect… make 2024 0.229 0.196 0.128 0.273 0.145
#> 3 powertrain Battery Elect… make 2021 0.299 0.258 0.194 0.346 0.151
#> 4 powertrain Battery Elect… make 2023 0.250 0.218 0.135 0.295 0.160
#> 5 powertrain Battery Elect… make 2022 0.337 0.309 0.166 0.442 0.276
#> 6 powertrain Diesel make 2023 0.225 0.215 0.207 0.225 0.0179
#> # ℹ 2 more variables: upper <dbl>, lower <dbl>