2024, Vol. 9, Special Issue 3

Most of the decisions concerning the future fertility behaviour are prejudiced by the number of surviving children instead of number of children ever born. Although, for studying the variation in the number of births occur to a female in a given period, various probability models are developed under the varying set of assumptions, yet very few studies are found to derive the distribution of number of surviving children out of the total births in a specified period. Thus it appears necessarily to attempt for finding the distribution of number of births as well as the probability distribution of number of surviving children. The specific period in which the study of conceptions and surviving children is carried out, is divided into two process i.e. equilibrium birth process and free process. Yadava and Tiwari (2006), derived the distribution of surviving children using some laws of probability. Hence, in this present paper, probability distribution of surviving children out of the total births, and average number of survived children in the free process is calculated by using same laws of probability and set of assumptions. The distribution of number of births and surviving children in the equilibrium birth process and free process is compared by considering the current mortality level 20 from West model life table.