Inequality in the Distribution of Income Within the Free Market - Disadvantaged Groups, Relative Poverty

Disadvantaged groups: a collection of people in an unfavourable condition and circumstance.
Percentile distribution: one percentile is compared to another, e.g. top 10% of population's income might equal the bottom 25%.
Lorenz curve: graph where a society's total income is ordered according to income level and the cumulative total graphed.
Gini coefficient: summary statistic used to quantify the extent of income inequality depicted in a particular Lorenz curve.
Standard deviation of income: measures income dispersion by assessing the squared variance from the mean.
Relative poverty line: measure of the no. or proportion of people or households whose level of income is less than some given fraction of typical incomes.
Poverty line: measure of the level of income necessary to subsist in a society. Calculated as that level of income at which a household will devote 2/3 of its income to basic necessities.
…