Parity progression ratios

A parity progression ratios (PPR) is a measure commonly used in demography to study fertility.

The PPR is simply the proportion of women with a certain number of children who go on to have another child.

[1] In more developed countries where two-child families are seen as the norm

(or the proportion of women with two children who go on to have a third) is of critical importance in determining overall fertility levels.

is simply the proportion of women who become mothers.