gini: Gini Index based on Gini (1921)

In ndi: Neighborhood Deprivation Indices

Gini Index based on Gini (1921)

Description

Compute the aspatial racial or ethnic Gini Index and retrieve the aspatial income Gini Index

Usage

gini(
  geo_large = "county",
  geo_small = "tract",
  year = 2020,
  subgroup,
  omit_NAs = TRUE,
  quiet = FALSE,
  ...
)

Arguments

geo_large	Character string specifying the larger geographical unit of the data. The default is counties geo_large = 'county'.
geo_small	Character string specifying the smaller geographical unit of the data. The default is census tracts geo_small = 'tract'.
year	Numeric. The year to compute the estimate. The default is 2020, and the years 2009 onward are currently available.
subgroup	Character string specifying the racial or ethnic subgroup(s). See Details for available choices.
omit_NAs	Logical. If FALSE, will compute index for a larger geographical unit only if all of its smaller geographical units have values. The default is TRUE.
quiet	Logical. If TRUE, will display messages about potential missing census information
...	Arguments passed to get_acs to select state, county, and other arguments for census characteristics

Details

This function will retrieve the aspatial Gini Index (G) of U.S. census tracts or counties for a specified geographical extent (e.g., the entire U.S. or a single state) based on Gini (1921) \Sexpr[results=rd]{tools:::Rd_expr_doi("10.2307/2223319")} for income inequality (at smaller geographical units) and race or ethnicity inequality (at larger geographical units).

The function uses the get_acs function to obtain U.S. Census Bureau 5-year American Community Survey estimates of G for the geospatial computation. The yearly estimates are available for 2009 onward when ACS-5 data are available (2010 onward for geo_large = 'cbsa' and 2011 onward for geo_large = 'place', geo_large = 'csa', or geo_large = 'metro') but are available from other U.S. Census Bureau surveys. The function will retrieve the provided income inequality metric (B19083) and the twenty racial or ethnic subgroups (U.S. Census Bureau definitions) are:

• B03002_002: not Hispanic or Latino 'NHoL'

• B03002_003: not Hispanic or Latino, white alone'NHoLW'

• B03002_004: not Hispanic or Latino, Black or African American alone 'NHoLB'

• B03002_005: not Hispanic or Latino, American Indian and Alaska Native alone 'NHoLAIAN'

• B03002_006: not Hispanic or Latino, Asian alone 'NHoLA'

• B03002_007: not Hispanic or Latino, Native Hawaiian and Other Pacific Islander alone 'NHoLNHOPI'

• B03002_008: not Hispanic or Latino, Some other race alone 'NHoLSOR'

• B03002_009: not Hispanic or Latino, Two or more races 'NHoLTOMR'

• B03002_010: not Hispanic or Latino, Two races including Some other race 'NHoLTRiSOR'

• B03002_011: not Hispanic or Latino, Two races excluding Some other race, and three or more races 'NHoLTReSOR'

• B03002_012: Hispanic or Latino 'HoL'

• B03002_013: Hispanic or Latino, white alone 'HoLW'

• B03002_014: Hispanic or Latino, Black or African American alone 'HoLB'

• B03002_015: Hispanic or Latino, American Indian and Alaska Native alone 'HoLAIAN'

• B03002_016: Hispanic or Latino, Asian alone 'HoLA'

• B03002_017: Hispanic or Latino, Native Hawaiian and Other Pacific Islander alone 'HoLNHOPI'

• B03002_018: Hispanic or Latino, Some other race alone 'HoLSOR'

• B03002_019: Hispanic or Latino, Two or more races 'HoLTOMR'

• B03002_020: Hispanic or Latino, Two races including Some other race 'HoLTRiSOR'

• B03002_021: Hispanic or Latino, Two races excluding Some other race, and three or more races 'HoLTReSOR'

Use the internal state and county arguments within the get_acs function to specify geographic extent of the data output.

According to the U.S. Census Bureau https://www.census.gov/topics/income-poverty/income-inequality/about/metrics/gini-index.html: 'The Gini Index is a summary measure of income inequality. The Gini coefficient incorporates the detailed shares data into a single statistic, which summarizes the dispersion of income across the entire income distribution. The Gini coefficient ranges from 0, indicating perfect equality (where everyone receives an equal share), to 1, perfect inequality (where only one recipient or group of recipients receives all the income). The Gini Index is based on the difference between the Lorenz curve (the observed cumulative income distribution) and the notion of a perfectly equal income distribution.' For racial or ethnic inequality, G is a summary measure of racial or ethnic unevenness or the mean absolute difference between a selected subgroup proportions weighted across all pairs of geographic units, expressed as a proportion of the maximum weighted difference.

Larger geographical units available include states geo_large = 'state', counties geo_large = 'county', census tracts geo_large = 'tract', census-designated places geo_large = 'place', core-based statistical areas geo_large = 'cbsa', combined statistical areas geo_large = 'csa', and metropolitan divisions geo_large = 'metro'. Smaller geographical units available include, counties geo_small = 'county', census tracts geo_small = 'tract', and census block groups geo_small = 'cbg'. If a larger geographical unit is comprised of only one smaller geographical unit (e.g., a U.S county contains only one census tract), then the V value returned is NA. If the larger geographical unit is census-designated places geo_large = 'place', core-based statistical areas geo_large = 'cbsa', combined statistical areas geo_large = 'csa', or metropolitan divisions geo_large = 'metro', only the smaller geographical units completely within a larger geographical unit are considered in the V computation (see internal st_within function for more information) and recommend specifying all states within which the interested larger geographical unit are located using the internal state argument to ensure all appropriate smaller geographical units are included in the V computation.

Value

An object of class 'list'. This is a named list with the following components:

g

An object of class 'tbl' for the GEOID, name, and G_re metrics of specified census geographies.

g_data

An object of class 'tbl' for the raw census values at specified smaller census geographies including G_inc.

missing

An object of class 'tbl' of the count and proportion of missingness for G_inc and each census variable used to compute G_re.

References

Gini, C (1921) Measurement of Inequality of Incomes. The Economic Journal, 31(121):124-126. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.2307/2223319")}

Duncan, OD, & Duncan, B (1955) Residential Distribution and Occupational Stratification. American Journal of Sociology, 60(5):493-503. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.2307/2088328")}

Massey, DS, & Denton, NA (1988) The Dimensions of Residential Segregation. Social Forces, 67(1):281-315. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.1093/sf/67.2.281")}

See Also

get_acs for additional arguments for geographic extent selection (i.e., state and county).

Other one-group evenness indices: atkinson, james_taeuber, sudano, theil

Between groups dissimilarity indices: duncan

Examples

## Not run: 
# Wrapped in \dontrun{} because these examples require a Census API key.

  # Gini Index (a metric of evenness) 
  ## of Black populations
  ## in census tracts of Georgia, U.S.A. (2020)
  gini(
    geo_large = 'county',
    geo_small = 'tract', 
    state = 'GA',
    year = 2020, 
    subgroup = c('NHoLB', 'HoLB')
   )
   

## End(Not run)

ndi documentation built on Sept. 9, 2025, 5:26 p.m.