Rees, P orcid.org/0000-0002-4276-9091, Clark, S orcid.org/0000-0003-4090-6002, Wohland, P et al. (1 more author) (2019) Evaluation of Sub-National Population Projections: a Case Study for London and the Thames Valley. Applied Spatial Analysis and Policy, 12 (4). pp. 797-829. ISSN 1874-463X
Abstract
Sub-national population projections help allocate national funding to local areas for planning local services. For example, water utilities prepare plans to meet future water demand over long-term horizons. Future demand depends on projected populations and households and forecasts of per household and per capita domestic water consumption in supply zones. This paper reports on population projections prepared for a water utility, Thames Water, which supplies water to over nine million people in London and the Thames Valley. Thames Water required an evaluation of the accuracy of the delivered projections against alternatives and estimates of uncertainty. The paper reviews how such evaluations have been made by researchers. The factors leading to variation in sub-national projections are identified. The methods, assumptions and results for English sub-national areas, used in five sets of projections, are compared. There is a consensus across projections about the future fertility and mortality but varying views about the future impact of internal and international migration flows. However, the greatest differences were between projections using ethnic populations. and those using homogeneous populations. Areas with high populations of ethnic minorities were projected to grow faster when an ethnic-specific model was used. This result is important for assessing projections for countries housing diverse populations with different demographic profiles. Historic empirical prediction intervals are used to assess the uncertainty of the London and the Thames Valley projections. By 2101 the preferred projection suggests that the population of the Thames Water region will have grown by 85% within an 80% empirical prediction interval between 45 and 125%.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © The Author(s) 2018, This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. |
Keywords: | Evaluation of Sub-National Populations; Projection Methods; Projection Assumptions; Projection Variants; Projection Uncertainty; Empirical Prediction Intervals |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Geography (Leeds) > Centre for Spatial Analysis & Policy (Leeds) |
Funding Information: | Funder Grant number ESRC ES/L013878/1 Thames Water Utilities Ltd no external ref |
Depositing User: | Symplectic Publications |
Date Deposited: | 14 Aug 2018 15:29 |
Last Modified: | 06 Dec 2019 16:08 |
Published Version: | http://springer.com/ |
Status: | Published |
Publisher: | Springer Nature |
Identification Number: | 10.1007/s12061-018-9270-x |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:134104 |
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