Atkinson, A(.5)
Atkinson (1970) proposed this class of inequality measures with  a weighting parameter e which measures aversion to inequality. As e rises, the index becomes more sensitive to transfers at the lower end of the distribution and less sensitive to transfers at the top. The limit case, e?0, the index reflects the Function of Rawls which only takes account of transfers to the very lowest income group; at the other extreme, when e=0, we obtain the linear utility function. This ranks distributions solely according to total income.