A consistency algorithm based on information theory

This paper provides a geometric‐mean solution to the consistency problem of multidimensional demographic projection models, based on the constrained minimization of an entropy function. A comparison with the existing harmonic‐mean solution yields many similarities and almost no differences: both solutions satisfy the properties of availability, monotonicity, homogeneity, competition, and symmetry, and, for both solutions, there is a convenient one‐to‐one relationship between adjustments in aggregate numbers of events, on the one hand, and age‐specific numbers of events, on the other hand. However, one major advantage of the geometric mean is that its corresponding distance function is firmly based on (information) theory.