Transcript School roll forecasting in Aberdeenshire

School Roll Forecasting
in Aberdeenshire
Richard Belding
Aberdeenshire Council
Aberdeenshire
in Scotland
Actual School Rolls
Aberdeenshire Area
22,000
21,000
20,000
19,000
Secondary Rolls
17,000
16,000
15,000
14,000
13,000
Date
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
1987
1986
1985
1984
1983
1982
1981
12,000
1980
Pupils
Primary Rolls
18,000
Brief History
• 1977 FORTRAN model run on ICL mainframe computer at
Grampian Regional Council
• 1984 program redeveloped on modular basis using Lotus 1-2-3
on IBM PC/XT microcomputer (each secondary school with its
feeder primary schools in a separate worksheet file)
• 1996 system converted to MS Excel at Aberdeenshire Council
after local government reorganisation
• System updated annually
• The fact that computer-based forecasts have been updated
annually for 30 years reflects demand but also recognition that
forecasts have limitations
Outline of Method
• Currently forecasts produced annually from council Sept school
census base for each stage (class/year) in each of 152 primary
and 17 secondary schools for each school year to 2016
• For each school, method involves rolling forward year by year
total pupils at each stage: seven primary (P1-P7) and six
secondary (S1-S6) stages offered
• Additional factors taken into account include:
- intake to primary schools
- out of zone admissions
- transfer from primary to secondary schools
- new house building and pupil yield
- pupils staying beyond statutory school leaving age
- constraints, migration and occupancy rate change
Not Included
• No single-sex, selective or denominational
state schools in Aberdeenshire
• No forecasts made for nursery, special or
private schools
• But need to cope with openings, closures,
and mergers of schools, phasing in and out
of pupils, primary zone (ie catchment area)
changes, secondary rezoning and
secondary destinations outside council
area
Intake to Primary Schools
• During first seven forecast years, school roll
increasingly influenced by P1 intake
• Annual extract from Community Health
Index (NHS patient register) of estimated
numbers of pre-school aged children resident
in zone used for first two P1 intake years
forecasted
• Beyond this, P1 intakes depended on
changes in birth totals at council area level
using GROS actual or council forecast figures
Out of Zone Admissions 1
• Adjustments to future P1 and S1 intakes to reflect recent levels
of out of zone admissions near start of these stages
• Movements expressed as net change to each school, and
forecast moves held constant over time
• Assumed that any net change due to out of zone admissions
only occurs near start of P1 or S1 (Any other changes of this
type only included when base roll updated to new base date)
• Assumed that out of zone admission to primary school does not
take place from residence outside of delineated secondary
zone containing that primary school’s zone
Out of Zone Admissions 2
• In current set of forecasts, effects of
admission limits and reserved places
on secondary school intakes have not
been taken into account
Transfer from Primary to
Secondary Schools
• Normally transfer from primary to secondary
education takes place according to standard set of
zoning procedures
• Assume that P7 pupils in a primary school at end of
summer term do not subsequently migrate out of
current secondary zone before or move to private
education at start of secondary schooling
• Then P7 stage will transfer in its entirety to one
secondary school unless:
- the cause is (or was) out of zone admission, or
- the primary school has split or dual zoning (in six
cases, separate forecasts produced for each part)
New House Building
• Number of estimated and anticipated completions of
dwellings by calendar year and primary zone
updated as at 1 January each year
• Certain developments excluded:
- small sites (below five units)
- sheltered housing sites
- sites consisting only or mainly of one bedroom flats
• Also included were major new developments
identified between 1 January and time of school roll
forecasts
Pupil Yield
• Number of pupils likely to be generated from newly
completed dwellings depends on type of property
• At primary zone level, forecast total P1-P7 pupil yield
(pupils per new dwelling ratio) used now varies
spatially from 0.30 to 0.45
• At secondary zone level, forecast total S1-S4 pupil
yield is either 0.15 or 0.20
• These totals are then distributed between stages
• A forecast pupil yield is held constant over time
Pupils Staying beyond Statutory
School Leaving Age
• Forecast staying on rates into S5 and S6
calculated from recent levels in school
concerned (held constant over time)
• But note changes in curriculum, availability of
places in further and higher education, job
prospects
• Scottish Government does not plan to raise
statutory school leaving age
Constraints, Migration and
Occupancy Rate Change
•
•
•
•
Council strategic forecasts of 5-11 and 12-15 year olds at 2011 and
2016 for Aberdeenshire were used to derive control totals for P1-P7
and S1-S4 pupil forecasts to take some account of net migration and
occupancy rate change within existing dwelling stock
Allowances made for factors such as special and private schools, as
well as out of zone admissions and secondary zoning movements
across council area boundary
Linear interpolation used at intermediate dates
For each year sequentially, proportional adjustment for all primary
schools in a secondary zone followed by same for S1-S4 in the
secondary school: changes feed through worksheet to later years
and stages for these schools
Compare with Capacity 1
• For each school and year, total roll
compared with school capacity (taking
into consideration only permanent and
linked temporary accommodation)
• Problems at primary level for current
update
Compare with Capacity 2
Actual and 2007 Based Forecast Roll and School Capacity
Meldrum Academy
1,200
1,000
Pupils
800
600
School Capacity
Total Actual Roll
Total Forecast Roll
400
200
0
2001
2002
2003
2004
2005
2006
2007
2008
2009
Date
2010
2011
2012
2013
2014
2015
2016
Error: General
• Initially assumed that when family moves out of zone, new
family replaces it with same number and age of children as
previously, but some subsequent allowance for occupancy rate
change within existing dwelling stock
• Number or date of anticipated completions of dwellings or
forecast pupil yield in zone may not be correct particularly in
long term
• To try to minimise inaccuracy, roll forecasts updated annually
• Because of independent rounding to nearest pupil, sum of
individual P1 to P7 or S1 to S6 forecast rolls may not be exactly
the same as total for each school
Error: Primary Schools
• A difficult part of primary school roll
forecasting is predicting P1 intake
• Particularly in settlements with more
than one primary school, where schools
relatively close together, out of zone
admissions may become an issue
Error: Secondary Schools
• In short term, most potential secondary pupils already
within local feeder primary school system
• In Aberdeenshire, secondary schools relatively
isolated spatially from each other: no settlement has
more than one secondary school, and this limits
impact of out of zone admissions, which may make
roll prediction more difficult (also admission limits
and reserved places can have effects)
• However, staying on rates into final two stages may
fluctuate from year to year in a school
Error: Small Schools 1
• Relative inaccuracy of forecasts for small primary schools can
be significantly influenced by movements of one or two
families into or out of zone
• Method uses changes in birth totals at council area level in
forecasts for individual primary schools, and anticipated
completions of dwellings on small sites not included (small sites
important in rural areas of Aberdeenshire which small primary
schools serve), thus forecasts for small primary schools must be
treated with considerable caution
• Data for small primary schools used in final primary
constraining phase and in secondary forecasts
Error: Small Schools 2
Inaccuracy One Year Ahead by Size of School
2006 Based Forecasts at 2007
Relative Difference from Actual
Roll (%)
40.0
30.0
20.0
10.0
0.0
-10.0
-20.0
Primary
Secondary
-30.0
-40.0
0
100
200
300
400
500
600
700
800
900
Actual Roll at Sept 2007
1,000
1,100
1,200
1,300
1,400
1,500
Error: Small Schools 3
Inaccuracy One Year Ahead by Size of School
2006 Based Forecasts at 2007 after Rounding
Relative Difference from Actual
Roll (%)
40.0
30.0
20.0
10.0
0.0
-10.0
-20.0
Primary
Secondary
-30.0
-40.0
0
100
200
300
400
500
600
700
800
900
Actual Roll at Sept 2007
1,000
1,100
1,200
1,300
1,400
1,500
Richard Belding
Aberdeenshire Council
10 September 2008
for the Annual Conference of the
British Society for Population Studies
(Revised but not updated 3 March 2009)