The study of the transitions that individuals experience over time, in the course of passing from one state of existence to another, is a fundamental dimension in much of mathematical demography. Recent work in multistate demographic analysis has led to a generalization of traditional demographic techniques for analyzing such problems. The papers in this issue are representative examples of work currently being carried out on this subject. A unifying thread is the use of matrix algebra to express multidimensional demographic processes in a compact and notationally elegant form which often leads to analytical insights that otherwise may be hidden in the more complicated nonmatrix formulations.