Natural rate of conversion to the new rules
This provides a view of how the proportion of the CSA caseload based
on the new scheme rather than the old scheme will increase over time,
even without a full conversion.
The ways that cases come under the new scheme
A CSA case will conform to the new rules for 3 main reasons:
Cases starting since 3rd March 2003 will start under the
new rules. (This includes cases that are considered to be such cases
because they were closed then restarted after a period of at least
Where a case is started under the new rules, if the PWC is already
a PWC of a different case under the old rules, or the NRP is already
an NRP of a different case under the old rules, the old case will
be converted to the new rules. (A parent cannot have a the same
role in 2 cases under different rules).
At a date (called the "conversion day") in the future, all
cases still under old rules will be converted at the next payment
date to the new rules (subject to phasing-in where relevant).
This page is restricted to types "1" and "2" - in
other words, what will happen before "convesion day"?
This estimate is simply a month by month picture, starting at the beginning
of March 2003 (when there were no cases under the new rules), for up to
3 years after this. It is unlikely that conversion day will be as late
as 3 years after 3rd March 2003, but no-one actually knows.
These are the assumptions built into the spreadsheet used to provide
||The starting caseload at 3rd March 2003 is taken as 1,088,000, estimated
from the state at November 2002. 
||The caseload is taken to increase about 15,000 per year. This is
estimated from CSA statistics over a number of year. 
||The number of new cases per year is predicted to be 340,000 per
year, based on statements made in Parliament. And the number of closed
cases per year is this number minus 15,000, hence leading to the above
increase in caseload per year. 
||20% of new cases are linked to existing cases (old or new). Hollis
stated this in Parliament. 
||Whether the cases that are linked to are old rules (hence converted
before conversion day) or are new rules is in the same proportion
as the proportion of old to new cases in that month. (This is a plausible
assumption to enable the sums to be done, but isn't supported by any
||Whether the cases that are closed in any month are old rules or
new rules is in the same proportion as the proportion of old to new
cases at the time. (This is an assumption to enable the sums to be
done, but isn't supported by any evidence. Furthermore, because it
implies that the probability that a case will be closed is independent
of its age, it is less plausible than some of the other assumptions,
and for the very oldest cases is wrong).
The graph on the right shows the approximate proportion of the
total caseload that are under new rules. (If conversion day doesn't
occur within the timeframe).
Start of March 2003: 0% (the new scheme started 3rd March)
Start of March 2004: 31%
Start of March 2005: 53%
Start of March 2006: 67%