1. Variant projections – some Scottish experience Jennifer Boag ex Cambridgeshire County Council ex Strathclyde Regional Council ex Central Regional Council ex Falkirk Council
I feel a bit as if I am here under false pretences, partly because I am ex so many different places, but also because, I am not sure just how much use has been made of variant projections by me or anyone else in Scotland. And when I actually came to put this presentation together, I found that there were a couple of other things I really wanted to say, rather than just talk about the use of variant projections.
Having said that, I strongly support the production of variant projections because of the opportunity which they give us to look at alternatives. It is something which the PAMS group have been supporting for some time – PAMS being the NRS group which oversees and advises on Census and population and household projections.

2. Scotland:
32 Council Areas 14 NHS Boards 4 Strategic Development Plan Areas 2 National Parks
Anyway, to take a quick look at Scotland and what NRS are producing their variant projections for:
Our geography is relatively straightforward in that we have 32 Council areas and 14 NHS boards which are either single local authorities or groups of local authorities – although that only became the case in April Before that the NHS areas matched the local authorities as they were before local government reorganisation in 1996, which meant that NRS had to use part local authority areas to match up to the Health Board areas.
However, mismatches remain.
Two of the four Strategic Development Plan areas are groups of local authorities – Clydeplan and Aberdeen and Aberdeenshire, but Sesplan and Tayplan split Fife between them.
And the two National Parks each contain bits of several council areas.

3. Areas vary in population size: Loch Lomond and The Trossachs National Park – 14,928 Clydeplan – 1,792,901 Councils: Orkney – 21,670 Glasgow – 606,340
Not helped by the fact that both National Parks are quite small in population terms. As you can see, the current population of the Loch Lomond and Trossachs National Park is under 15,000, which is getting towards the lower limit of size for population projections to work.
And there is a big variation in size overall – up to 1.8million for the Clydeplan area.
And even for the local authorities size varies from 21,700 for Orkney, with the two other islands councils under 30,000, up to over 600,000 for the city of Glasgow.

4. Case study: Strathclyde Region 1976
Population decline in 1960’s and early 70’s esp from Glasgow Council policy to reverse this decline So we did our own projections
1974
1981
MYE
RG’s projection
SRC Projection
Census
Glasgow
905,000
742,000
788,500
755,429
Strathclyde
2,527,100
2,430,000
2,375,410
So, let’s look at a few case studies from Scotland which perhaps point out some of the reasons why variant projections are useful.
The first goes back quite a long time, to the 1970’s. At that time, population in Scotland was falling, largely due to a very high level of net out-migration.
When local government reorganisation took place in the mid 1970’s bringing in a two tier system of Regions and Districts across most of the country, Strathclyde Regional Council, which covered about half the country in terms of population, took a decision that something would have to be done about population decline, especially in the city of Glasgow.
So the trend based projections produced by the then Registrar General for Scotland were rejected and they chose to do their own projections for some of the council areas. Projections were relatively short term in these days – only 7 years forward to Strathclyde Region kept the overall GROS projections, but changed the balance within the Region so that the population decline in Glasgow would be stemmed. By 1981 they had only been partly successful as the Census figures show, although in the longer term population decline is no longer as big a problem, because Scotland now has net in-migration.
This brings me to my first point, even with variant projections, any trend based projections are often not useful if councils, or others, want to bring in policies to change the trends. The current trends show what would happen if nothing changes compared to the last few years, which is useful, but may not be what is required for planning purposes.

5. Case study: An object lesson in over optimism - Grangemouth Falkirk Regional Survey and Plan 1968
1961
1986
Census
Plan Projection
MYE
Grangemouth Falkirk Growth area
124,167
230,000
Falkirk Council area
143,830
I have already drawn attention to how successful policies can be in changing the future level of population with Strathclyde Region being only partly successful.
This slide comes from one of my favourite reports of all time, part of the swathe of regional development plans which were very much the fashion in the 1960’s and 70’s.
The 1968 Plan for the Falkirk and Grangemouth area was predicated on economic growth, centred on the Grangemouth petro-chemical complex, which would lead to the population growing to 230,000 by 1986, 25 years on from the base population of the 1961 Census.
By 1986 the population of the whole of the Falkirk Council area was only 144,000 and this was a much bigger area, probably at least 20,000 more than the development plan area.
Which brings me to my second point, how can you be realistic about what might happen in the future?
Variant projections give us some indication of the amount of change in the projections which can be expected from certain changes to the underlying assumptions and so can also be useful if you want to do your own projections, in working out how much change you would need to make to the assumptions – and how realistic that might be, to get the level of change you want in your projections.

6. Case study – Falkirk Council First Structure Plan
Local government reorganisation 1996
My third case study is another one about why we sometimes need to do our own projections.
In 1996 local government was reorganised in Scotland and Falkirk Council became a structure plan authority in its own right, which meant we had to embark on the process of producing our first plan.
As you can see from the graph, and yes I do know it is a gee-whiz graph and the left hand axis covers quite a short scale, but you can easily see that the population had been falling, albeit slowly from 1981 – in fact from before then. However in 1994, the trend changed and the population started to increase.

7. Case study – Falkirk Council First Structure Plan
GRO(S) projections 1996 base
As we expected, when the 1996 base GROS population projections were produced, based on recent trends, the projected population showed a decrease. And you can see how this compares with what actually happened to the Council area’s population over the next 20 years.

8. Case study – Falkirk Council First Structure Plan
Falkirk Council projections to 2020
1996 base
Falkirk Council projections to 2020
GRO(S) Projections to 2013
2013 MYE
Falkirk
143,040
146,000
140,422
157,160
So we did our own projections as the Council wanted to build on the very recent change to the trend and see a growing population in the area.
However, once again you can see that although we suggested a growing population, we were looking at 146,000 by 2020, a figure which was actually achieved by 2003!
This was partly because there was an upturn in the birth rate in the early 2000’s and also because Falkirk saw a substantial increase in net in-migration, higher than we anticipated, which was fuelled by a big increase in house building which in turn was helped by relatively low house prices compared to neighbouring areas like Edinburgh and Stirling.
And you can see from the table, the projections by GROS to 2013 and the actual mid year estimate.
Which brings me to another of the points I want to make. How far do we assess the accuracy of our projections by looking back at the past projections and seeing how accurate they turned out to be?
I know ONS have done some work on this and to some extent trend based projections explain themselves – the trends changed!
But I would like to see more done on how we can get our projections, and more importantly the underlying assumptions more accurate

9. Case study – Falkirk Council 2010
Falkirk Council input to Local Development Plan Opted for principal population projection – consulted on migration assumptions BUT opted for alternative household projection
2010 base
NRS Principal Projection to 2035
NRS Constrained housing variant
Falkirk
Population
153,280
168,688
Households
68,660
84,230
83,180
My next case study relates to the work we did for the Local Development Plan which replaced the previous Structure Plan and its revision.
By this time, GROS had become NRS and they were producing variant projections for Council areas.
In Scotland there has been a tradition of NRS consulting local authorities on their migration assumptions before they produce their population projections. In Falkirk we were successful on a couple of occasions in getting NRS to make changes to their assumptions, so we didn’t feel there was any reason to use any of the variant population projections. If we hadn’t agreed with the migration assumptions
However, we did choose to use one of the variant household projections. NRS have been doing the household projections in Scotland as well as the population projections for quite a long time and I hope the move in England for ONS to take over the household projections will be as successful as in Scotland.
By 2010, there were concerns about the headship rate figures which were being used. I certainly felt that the headship rates were showing a larger increase in single person households than could be sustained in the longer term, and there was also the effect of the economic downturn from 2008 onwards which appeared to be showing a decrease in the rate of household formation. In Falkirk we opted to use what was called the constrained housing variant which reduced the household formation rate in the short term in line with the recent decrease in household formation.
It was good to have a choice, based on recent information.

10. Case study – Falkirk Council 2014 based projections - variants
Falkirk Council projections to 2039 – spoilt for choice! Base population 157,690; Council opted for Principal projection
Projected population 2039 by variant
Zero outwith Scotland migration
Low migration
Low fertility
Low life expectancy
Principal
High life expectancy
High fertility
High migration
Falkirk
163,257
165,951
166,815
168,696
170,870
173,014
174,982
176,051
And finally, we are almost spoilt for choice in the latest set of population projections, on a 2014 base published last October.
I can’t claim any credit for the choice the Council made this time since NRS only published their projections a month after I officially retired, but I assume that there was no reason to pick any alternative projection, if we were happy with the migration assumptions.
I have always felt that Councils were not really in a position to decide on alternative fertility and mortality figures, and could do very little to alter them anyway, while we can influence migration by looking at the amount of land we provide for new housing.
However, we all know how fertility rates have fluctuated over the last 60 years or so and I know there are concerns that in the last couple of years, mortality seems to have increased across the UK, so maybe we should pay more attention to these aspects of the projections.
In conclusion, I strongly support producing variant projections a they give us a better picture of alternative scenarios.
However, I think we have to get better at making our own more realistic assumptions about future growth levels, and do more to check back and see how accurate our projections have been – and why.

11. Questions?
Points for discussion: