MODELING THE DROPOFF BETWEEN MINORITY POPULATION SHARE AND THE SIZE OF THE MINORITY ELECTORATE IN SITUATIONS OF DIFFERENTIAL VOTER ELIGIBILITY ACROSS GROUPS

In any constituency partitioned into two discrete and mutually exhaust ive groups, the difference between a group's share of the eligible ele ctorate and its share of the total population will depend, on the one hand, on the differences in the age structure and eligibility rates of the two groups and, on the other hand, it will also depend upon the r elative population sizes of the two groups. We model the exact nature of this relationship, providing formulae which allow us to ascertain t he maximum difference between a group's share of total population and its share of the eligible electorate and to specify the percentage for 'effective voting equality', i.e. the population proportion in a cons tituency for a group whose members have lower rates of voter participa tion needed to equalize the sizes of each group's eligible electorate. We discuss the applicability of these results to remedial districting plans in black/Hispanic voting rights cases in the United States and their implications for the differential holding of identity papers amo ng blacks and non-blacks in South Africa. Copyright (C) 1996 Elsevier Science Ltd.