On the contrary, they allow placing progressively less weight on incomes higher up or down the distribution, such as from top to average incomes, from average to median incomes, from median to bottom incomes (Box 2). The equally distributed equivalent level of income is the level of income per head, which if equally distributed, would give the same level of social welfare as the present distribution. Clearly, the general mean reduces to the standard mean or equivalently the average when a = 1. The case where a = 0 is called the geometric mean whereas a = -1 is known as the harmonic mean. General means as income standards (cont.) The income standard pa(x) places greater weight on higher incomes and less weight on lower incomes as the parameter rises.