Population dynamics based on birth intervals and parity progression

The Chinese population policy of 'later-longer-fewer' suggests a formulation of population dynamics in terms of birth intervals and parity progression. This leads to population projections based on birth interval distributions and parity progression ratios and to an alternative to Lotka's stable population theory in which age is replaced by parity and interval since last birth. A numerical comparison with Lotka's model indicates similarities and differences between the two approaches: The formulation suggests an approach to the analysis of birth interval and parity progression statistics that effectively solves censoring and selection problems.