c - usaid

17
In the light of trend-based. and other projactios, there
is high probobi ti ty that "ha point (B1,02 1n figure 3. I iay be
on the se9ment marked CT on tho TFR-targot Line (or in an area
adjacont to it]. More datai Ls rolating to this wi l be provided
[ i n r,ection 5] in connection with tho modified version of the
Popu lat io n Counci ' s modeL. The main purpose of referring to this
aspect at this stage is to hig1hlight the need for a clear Linkage,
within t he modeL, between tha to rgetted or enti ated values of TFR
and CUR, and this mus t involve also the third important factor,
name ly CP 1.
Use of ASFR as an input
-- - - ----------------
Another deficiancy of the Population Counci L's model is
that it considers th age-specific ferti lity rates of the target
year, i . e. ASFR[ t) as an itnput. In other words, we are supposed
to know in advance what the oven ASFR' s wilL be in the target
year. Those and other inputs will then help in estimating, through
the model, the required rates of contraceptive prevalence in the
various
age-groups.
One can app rtciate why ASFR( t) has been considered as an
input in the modeL. This is because the ego-specific version ef
the model is
vieved as a simple ex tansiion of the aggregate model.
In t1e aggregate model, TFl ( t) is an input and CPR(tI is an
output. y a simple analogy, TFR (t i replaced by ASFR(t) in
the age-speci fic mcd L. However, this iS only one of the ways of
movin g from an aggreugate to an age-specific version. It itS