# Measures

TODO:: separation of shares, inequality indices and ratios

**absolute** shows magnitude of difference between subgroups of pop -> focus on absolute welfare

**relative** shows proportional difference between subgroups of pop -> focus on welfare in relation to others

## Direction

### Vertical

Gini coeff, Theil, entropy measure, atkinson indexes

### Horizontal

mean differences between groups; ratios between better off/worse off

GGini; GTheil; GCOV


## All indicators
### Absolute

* quantiles (division by 5) / deciles (division by 10) / centiles (division by 100)

* Absolute Gini index 
    * ?

* Standard deviation 
    * deviations from norm in *absolute* terms

### Relative


* ratios of quantiles to each other (division of various quantiles)

* Gini coefficient:
    * based Lorenz curve - population percentage versus accumulated fractions of wealth
    * is area between lorenz curve and perfect equality
    * needs: individual/household income/wealth; pop size

* Theil index:
    * how much income distribution (person x receives y from total income) is away from perfect uniform distribution
    * log -based
    * can be disaggregated into subgroups
    * Theil L > weighting factors are population groups; Theil T > weighting factors are fraction of appropriated income

* Atkinson measures:
    * measures cumulative deviation of each income in relation to average income value in distribution

* Palma ratio:
    * dividing share of income/wealth held by top 10% by bottom 40%, thus high = bad

* s80s20, s40s20 ratios:
    * ?

* Concentration index:
    * divide whole pop by 100 to find percentiles
    * then you know how many ppl are in each group and add their total income

* Foster-Greer-Thorbecke-class distribution (@Sotomayor2021)

