Satisfactory calculation methods are currently available for implementing the movement approach to the calculation of increment-decrement life tables. By contrast only heuristic calculation methods have been suggested for implementing the alternative approach; namely, the transition approach, which is relevant in the analysis of interregional migration from census information. 

This paper presents an improved methodology for calculating increment-decrement life tables from the transition perspective. First, it suggests a method for estimating transition probabilities which is an interpolative variant of Rees and Wilson's averaging method tailored to the type of data commonly available. Then, it proposes an alternative to the usual linear integration method for calculating the multistate counterpart of the L-statistics of an ordinary life table.