The authors reply to Zax's critique of the double-equation method for ecological regression and of the specific extension to it proposed by Grofman and Migalski. Although Zax does correct two minor errors in Grofman and Migalski's statement of the double-equation approach, neither of those...

Two families of indices are defined which may be used to characterize the effective number of components in systems with unequal component sizes. A general formula is staled relating size, effective size, and effective number of components. Special cases of this formula are considered which...

We extend the standard ecological regression methodology for analysis of racial bloc voting in single-member districts in which there is one seat to be filled to cover multimember districts without a numbered-place system. In such multimember districts voters may vote for up to k candidates and...