c - usaid

61
roach 0.9.
(vi) Age-specific contraceptive prevaLence rates and the overall
CPR for the bore year.
These are mainLy avel table from CPS­
]'O but a ve been adjusted, as already explained in Block I
of our modal.
A noteworthy feature of our modal is that it uaee relat've
values of the natural fPrti Lity pattern (assumed to be the aeme
for tie base year as wall as the targ ot year] as an input rather
than age-speci fic ferti lity rates for the target year.
Corrasponding to each pattern of natural fe rti Li ty, the three
parameters Fl, K and 0 are assigned values within stipulated ranges
so as to obtain ertimates of ASFR' s, age-speci fic CPR' s, TFR and
CB R. Our model offers a wide choice, but there a re I imi ts to how
Low the values of TFR and CBR can be in practice because of the
need to retain internal consistency. Total population in the
target year is n aded by us as an input for estimating CBR. The
Population Council's model does not require thie input because
it
does not
make any direct estimate of CB R.
- By using four patterns of natural fertility for each of the
targot years, we obtained, among other thingst the f LLow ing
estimates of TFR and CBR:­