How many children does Serbia need?

The work is an attempt to determine basic quantities for introducing a family planning program which will be aiming at a replacement level. In order to do that census year 2002 was taken as an example for calculation. Total fertility rate of 2.1 children per woman was considered as necessary level and that means Serbia needs 105.000 newborns each year. In accordance with that level a set of five age specific fertility rates (ASFR) were established in order to find appropriate model of reproductive behavior for Serbia. The sets are established in the following manner: multiplying ASFR by quotient between necessary and real number of newborns, by the data from the last year when fertility was large enough to provide for replacement level (with mortality level from 2002), by linear interpolation between two ASFR models and by Brass fertility polynomial. All five different models of age specific fertility rates suggest that there is no ideal distribution of ASFR. Also parity progression from zero to first, from first to second, and from second to third child is determined. The main reason for below replacement level in Serbia is small parity progression from second to third child. So, rearing the third child should be the most stimulated in every family planning program, as long as every second women have them by the end of her reproductive life span