Evaluation, Revision and Extension of Ethnic Population Projections - NewETHPOP

Lead Research Organisation: University of Leeds
Department Name: Sch of Geography


This project aims to understand and to forecast the ethnic transition in the United Kingdom's population at national and subnational levels. The ethnic transition is the change in population composition from one dominated by the White British to much greater diversity. In the decade 2001-2011 the UK population grew strongly as a result of high immigration, increased fertility and reduced mortality. Both the Office for National Statistics (ONS) and Leeds University estimated the growth or decline in the sixteen ethnic groups making up the UK's population in 2001. The 2011 Census results revealed that both teams had over-estimated the growth of the White British population and under-estimated the growth of the ethnic minority populations. The wide variation between our local authority projected populations in 2011 and the Census suggested inaccurate forecasting of internal migration. We propose to develop, working closely with ONS as our first external partner, fresh estimates of mid-year ethnic populations and their components of change using new data on the later years of the decade and new methods to ensure the estimates agree in 2011 with the Census. This will involve using population accounting theory and an adjustment technique known as iterative proportional fitting to generate a fully consistent set of ethnic population estimates between 2001 and 2011.

We will study, at national and local scales, the development of demographic rates for ethnic group populations (fertility, mortality, internal migration and international migration). The ten year time series of component summary indicators and age-specific rates will provide a basis for modelling future assumptions for projections. We will, in our main projection, align the assumptions to the ONS 2012-based principal projection. The national assumptions will need conversion to ethnic groups and to local scale. The ten years of revised ethnic-specific component rates will enable us to study the relationships between national and local demographic trends. In addition, we will analyse a consistent time series of local authority internal migration. We cannot be sure, at this stage, how the national-local relationships for each ethnic group will be modelled but we will be able to test our models using the time series.

Of course, all future projections of the population are uncertain. We will therefore work to measure the uncertainty of component rates. The error distributions can be used to construct probability distributions of future populations via stochastic projections so that we can define confidence intervals around our projections. Users of projections are always interested in the impact of the component assumptions on future populations. We will run a set of reference projections to estimate the magnitude and direction of impact of international migrations assumptions (net effect of immigration less emigration), of internal migration assumptions (the net effect of in-migration less out-migration), of fertility assumptions compared with replacement level, of mortality assumptions compared with no change and finally the effect of the initial age distribution (i.e. demographic potential).

The outputs from the project will be a set of technical reports on each aspect of the research, journal papers submitted for peer review and a database of projection inputs and outputs available to users via the web. The demographic inputs will be subject to quality assurance by Edge Analytics, our second external partner. They will also help in disseminating these inputs to local government users who want to use them in their own ethnic projections. In sum, the project will show how a wide range of secondary data sources can be used in theoretically refined demographic models to provide us with a more reliable picture of how the UK population is going to change in ethnic composition.

Planned Impact

Impact summary
The project will develop new estimates of local ethnic population estimates and components for the 2001-2011 decade and use them to produce new projections of the UK's ethnic transition. To do this we will need to apply demographic methods in innovative ways and to develop a new projection model compatible with ONS's Conceptual Framework for Population and Migration Statistics.

The Office of National Statistics (ONS) will benefit from co-production of revised estimates of ethnic population change. The ONS team and the project team will discuss their respective methods and data sets for revising the 2001-2011 ethnic estimates. Although the ONS revised PEEG estimates and the Leeds/Newcastle NewETHPOP estimates will be separate products, the collaboration will produce aligned data sets. The project may help in moving the PEEG estimates from the status of experimental statistics to official statistics status.

ONS will benefit from use of a full set of estimated migration flows between local authorities in and between all home countries that make up the UK (based on the work of Lomax et al. 2013 and Lomax 2013) and the total out- and in-migration classified by ethnicity which we develop in the project. We note that Eurostat require from the UK statistical agencies information on migration flows between local authorities within the whole country and their aggregations to regions defined in the Nomenclature des unites territoriales statistiques (NUTS). In a previous project Dennett and Rees (2010) supplied migration flow estimates for NUTS 2 regions to Eurostat on behalf of ONS.

ONS have a goal to produce confidence limits in future versions the National Population Projections based on probabilistic projections. We anticipate that our experience in producing probabilistic projections for local ethnic group populations will be helpful for this programme.

We will inform the statistical agencies of the devolved administrations (the Welsh, Scottish and Northern Ireland Governments) of the progress of our work, which will be of considerable interest. The 2011 Census provides ethnic classifications much better harmonised than in the 2001 Census, so we will be able to produce and publish local authority estimates and projections for these home countries.

Working with non-academic partner Edge Analytics, we will disseminate our new estimate and projection data to Local authorities (LAs). They will have access to a new updated set of ethnic population projections via the web interface and database. They will have access to our ethnic component estimates and assumptions for use in their own projections, based on the POPGROUP software. We will consult with colleagues at the Greater London Authority (GLA) and keep them informed of our work. Both Edge Analytics and the Leeds/Newcastle team have carried out work for the GLA. The GLA produce the most comprehensive set of local authority ethnic projections in the UK.

We will also aim to reach a wide variety of other users. The ETHPOP user list has currently ~200 registered users The largest group are academic users (58), NHS users (36) and a government users (36). There are also researchers who use a private account and from organisations such as diabetes.org, mariecurie.org, havenhouse.org, bmecancer and demelza.org. A few subscribers are from newspapers, consultancies and other private sector companies.


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Description EVALUATION
Previous 2001-based ethnic population projections were compared against populations in the 2011 Census. The White population was over-projected and the minority ethnic population under-projected. Our assumption about mortality rate decline (2% pa) was too optimistic compared with the outcome for the decade (1.2% pa). Too many White British, the oldest ethnic group, survived. Also immigration by other groups was under-estimated. The lesson was we needed to improve our ethnic component estimates when updating the projections with 2011 Census data.

The projections were extended at local authority scale to all of the UK. We invented methods for reconciling the component rates to the "book ends" of the 2001 and 2011 Censuses. Our mortality estimates used the geographical distribution method, dropping the link to long-term limiting illness. Our fertility estimates employed new census and births data for 2011. Our estimates of internal migration included all UK local authority to local authority flows. Use of 2001 Census Microdata produced better ethnic specific estimates. We reconstructed tables of immigration and emigration by age, gender, region of destination/origin and country of birth from the International Passenger Survey. These tables were combined with census data on country of birth and ethnicity and official estimates of local immigration and emigration to produce better local estimates.

The ethnic population projection model was re-designed to align with the ONS framework for demographic statistics. Two innovations were introduced: migration was treated as an event rather than a transition; populations at risk were calculated using an iterative method. The bi-regional cohort-component model handles the populations of 389 local authorities and 12 harmonized ethnic groups or 4,668 sub-populations for single years of age to 100+ by gender.

We have produced two ethnic population projections for UK local authorities, based on information on 2011 Census ethnic populations and 2010-2011-2012 ethnic components. Both projections align fertility and mortality assumptions to ONS assumptions. Where they differ is in the migration assumptions. In LEEDS L1 we employ internal migration rates for 2001 to 2011, including periods of boom and bust. We use a new assumption about international migration anticipating that the UK may leave the EU (BREXIT). In LEEDS L2 we use average internal migration rates for the 5 year period 2006-11 and the official international migration flow assumptions with a long term balance of +185 thousand per annum. We compared our LEEDS L2 results against the ONS National Principal projection; our projections reach a UK population in 2061 just above 80 million compared with an ONS population just below. The uplift results from a drift of the population in our subnational projections towards faster growing ethnic groups and local authorities. Our new results suggest faster growth of ethnic minorities and slower growth followed by decline in the White population. There is a continuing diffusion of ethnic diversity to the rest of the country from cities receiving immigrants. This diffusion is greater when ten year internal migration rates are used compared with five year rates.
Exploitation Route We have revised our web site and database to hold our new projections and supply data outputs for others to use.

During the project we have been in frequent discussion with potential users of our projections. For some we have supplied some interim updates but now our full outputs are available. A full account of how to access these are the revised Narrative Impact Report. This report describes the use of our projections in work for Thames Water Utilities Ltd. We investigated water use by ethnic groups and established that per capita consumption by households with an "Asian" (Indian, Pakistani or Bangladeshi) household representative (bill payer) was up to 50 litres per day greater than "non-Asian" households. We then used the PHC and PCC information in conjunction with our ethnic population projections to forecast water demand in the Water Resource Zones of Thames Water. We extended the horizon for projections to 2101 to gauge long-term water demand and converted population projections in household forecasts for households classified by ethnicity of representative, household size and property type, the principal drivers of water demand. To our knowledge, no other work has included projected values of these drivers in water demand.
Sectors Communities and Social Services/Policy,Education,Environment,Healthcare,Government, Democracy and Justice,Other

URL http://www.ethpop.org
Description NARRATIVE IMPACT REPORT Philip Rees, School of Geography, University of Leeds, Leeds LS2 9JT, UK Email: p.h.rees@leeds.ac.uk, Mobile: 07584 098247 Original Report: 30 August 2017, Revised Report: 12 March 2018 ESRC Research Award ES/L013878/1 (1 January 2015 to 31 August 2016) NewETHPOP-Evaluation, Revision and Extension of Ethnic Population Projections Principal Investigator: Philip Rees (University of Leeds), Co-Investigators: Pia Wohland (Hull and York Medical School) Paul Norman (University of Leeds), Nikolas Lomax (University of Leeds) Post-Doctoral Research Fellow: Stephen Clark (University of Leeds) 1 Overview This document reports on the continuing impact of the NewETHPOP research project since the completion of the ESRC project on 31 August 2016. Section 2 reports that our web site now delivers a results database and full downloadable results, providing access to potential users of our results. This provision complements the full set of results deposited with the UK Data Archive in 2016. Section 3 lists our published outputs (book chapters now in print), journal papers in preparation, associated reports and presentations. Section 4 describes a new research project in which the ethnic population projections generated in NewETHPOP have been extended to 2101 and used to forecast water demand for Thames Water Utilities Limited. This is a major impact of our work. Section 5 describes a number of smaller collaborations with our partner organizations, the Office for National Statistics and Edge Analytics Ltd, recruitment planners and local authorities. Section 6 reflects on our achievements and identifies how we will continue to build on the ESRC funded project work in future. 2 Population projections implemented in the NewETHPOP project and subsequently Table 1 sets out the sets of population projections for UK local authority districts (LADs) by ethnicity which we have generated to date. The first set of three, HIGH, MID and LOW, are scenarios that vary by international and internal migration assumptions. The international migration assumptions are the main influence on the level of ethnic group populations while the internal migration assumptions affect their redistribution between LADs. The MID and LOW projections are made available on the website (http://ethpop.org/) re-launched in mid-2017 in three ways. The first way is via a database from which the user can select data for a small set of areas. The second way to access these projections is as zipped files in the website repository. The third way is to download all the files as one (large) zip archive from the UK Data Service repository. The HIGH scenario, which assumes international migration levels continue at the levels of the 2010-2015 period, can be obtained from one of the authors listed. These projections used the same NPP2014 assumptions for fertility and mortality, converted into assumptions by ethnicity for 389 local authority districts. The second set of three projections, labelled HIGH-R, MID-R and LOW-R, were developed for use in a paper on the roles of international and internal migration on the UK's ethnic group, submitted to Demography and now in revision. These differ from the first set by using the same internal migration scenario, so that differences can be attributed to the different international migration scenarios. In addition we have revised the pace of decline assumed for the low scenario so that the government's target of a net international migration of no more than 100 thousand per annum is achieved in 2031-32 rather than 2079-80 as in the LOW scenario in the first set. Results from this set are available from the authors. The third set of projections listed in Table 1 is longer term versions of the scenarios in the first set. The projections are rolled from 2061 to 2101, in order to provide forecasts of the populations of water consumers for Thames Water Utilities Limited in a project described below. A fourth scenario was added at the end of the project at the request of stakeholders, which explored a change from assuming constant fertility to assuming convergence of ethnic fertility rates on the fertility rates of the White British and Irish majority population. 3 Publications and presentations Table 2 reports on published and planned outputs from the NewETHPOP project and the work for Thames Water which used the projection rolled out to 2101. Table 2.1 lists the outputs (book chapters) which have now all been published. "Green" versions are available via the White Rose Repository maintained by the Universities of Leeds, Sheffield and York. Table 2.2 reports on the set of journal papers in various stages of preparation based on work in the NewETHPOP project. The first paper has been submitted to and reviewed by the journal Demography and is now in revision. The next four journal papers are at various stages of writing, working from drafts written during the NewETHPOP award period or in 2017. They cover the topics of ethnic fertility convergence, the variation in speed and intensity of population ageing across ethnic groups, an analysis of the projected population of ethnic groups across the UK's cities and an account of the methods we used for estimating LAD level immigration and emigration and how we defined our LOW migration to reflect the potential impact of Brexit via a change in controls by citizenship. An invitation to publish this latter paper has come from the senior editor of Population, Space and Place. The final item listed in Table 2.2 is a book based on our NewETHPOP work. The book will discuss the main findings of the project, reporting on the drivers of the future ethnic mix of population, nationally and in local detail. We will also provide a detailed account of methods and data sets used in component estimation and in projection together with chapters on the implications of Britain's ethnic transition. We took the decision to start work on the book only after submission of the planned journal papers. Section 2.3 lists publications in preparation arising the project for Thames Water. The first paper on Projections of Domestic Water demand has been reviewed by the Journal of Water Resources Planning and Management and is currently being revised for publication. The second paper on a comparison of our NewETHPOP projections with three other sets of sub-national projections has been reviewed by the journal Applied Spatial Analysis and Policy and is being revised for publication. The draft of the third paper focused on household projections is nearing completion. We have contributed to the consultation by the Office for National Statistics on methods of household projection and persuaded them to adopt many of the features we used in our projections. Table 3 lists the presentations of NewETHPOP and Thames Water results to a variety of audiences. 4 The Thames Water Project We were approached in summer 2015 by Thames Water Utilities Ltd (TW) to undertake work on the future populations, households and water demands in the TW Water Supply Zones. This proposal was designed to inform the preparation of their next strategic management plan for 2019 to 2024, incorporating a longer-term horizon for water demand forecasts to 2101. We agreed to do the work from 1 June 2016 to 31 May 2017. 4.1 The nature of the TW projections Why did TW want ethnic specific, long-term population projections? Prior work had established that households which differed by ethnicity also differed in their Per Household and Per Capita consumption. TW also required a long-term forecast at a subnational scale. Long-term forecasts to the end of the 21st Century were needed because the long period for planning and then building major water supply infrastructure (at least 20 years) and because of the long life-time of water supply infrastructure (at least 90 years into the future). As a result of work on subnational (LAD) population projections in three ESRC funded projects we were in a position to deliver what was required. We used our two published NewETHPOP projections and added a third (the High or L0 projection) as the basis of forecasts from 2011 to 2101. Features needed to be added to achieve the aims of TW. First, we needed to convert 60 of our LAD projections into forecasts for 6 TW Water Resource Zones (WRZs), using geo-conversion techniques. Second, we needed to aggregate from our 12 ethnicities to the 2 required by TW, which were Asian (Indian+Pakistani+Bangladeshi or IPB ethnicities) and Non-Asian (Ethnic groups other than the IPB) groupings. Prior work for TW had identified IPB households as consuming significantly more water than non-IPB households. Third, we extended our projections from 2061 to 2101. Fourth, we converted our projections into household forecasts classified by occupant number, property type and ethnicity. Fifth, we were asked to review the feasibility of adopting projections guided by housing plans rather than trends in the components of change, which is the standard approach. After review and investigation, it was agreed that only a trend approach was feasible over the 90-year forecast horizon. 4.2 Stakeholder concerns Table 4 lists the Reports produced for Thames Water produced over the year and presented at project meetings in London and Reading. We also supplied results for a TW stakeholder meeting in April 2017 and presented results at a TW Stakeholder meeting in July 2017. Stakeholders at both meetings raised concerns about the high level of our forecasts compared with official projections. TW asked us to do additional work to compare our forecasts with alternatives and in follow on work in August and September 2017 to run a further projection that including a convergence assumption for ethnic fertility. A new fertility scenario was prepared and a report written in August 2017. 4.3 The role of international migration assumptions Future population change depends crucially on the level of international migration gains: high, mid or low. Table 5 reports on projected populations at 30 year intervals for TW WRZs combined (the TW region). Under the High 2015-16 migration levels, the TW region's population grows by 111%. Under reduced international migration of the Mid assumption, that tracks the ONS NPP2014 assumptions, the population still grows by 85%. Under the Low scenario, in which the international migration assumption is designed to capture the effect of Brexit, growth is only 27%. However, the effect of Brexit does not kick in until after 2041. In the final period, 2071-2101, growth declines when net international migration is restricted to +100 thousand. These alternative population scenarios all imply substantial shortfalls in water supply for the Thames Water region, given lower summer rainfall implied by climate change and the need to reduce river abstraction. 4.4 Differences in the projected growth of IPB and non-IPB populations The IPB population grows much more strongly than the non-IPB ethnic group population, because of its younger age distribution which is concentrated at the start of the period in the family building ages and higher fertility rates. So, the share of the IPB population grows from 9% in 2011 to 21% in 2101 under all scenarios. As IPB households have Per Capita Consumptions of about 50 litres per day more than non-IPB households, water consumption will be higher for an ethnically specific projection than for one that does not consider ethnic heterogeneity. 4.5 The slowdown in growth after 2071 An outcome that emerges in the TW projections is that, before 2071, growth is linearly upwards but, after 2071, it begins to slow down. It becomes population decline in the Low scenario. This effect is not visible in the NewETHPOP projections, which extend only until 2061. The reason for this slowdown in each scenario is that eventually natural decrease (more deaths than births) occurs under the assumption that average fertility remains below 2.07 (replacement level). At first the natural decrease is compensated for by net international migration. But, because the international flows are held constant in absolute terms, their compensating effect becomes less important over time. 4.6 Comparison of Population Forecasts Thames Water asked us to compare our projections against alternative sub-national projections by Greater London Authority, the Office for National Statistics and Edge Analytics. Total projected populations are assembled in Figure 1 for years over which comparisons can be made, using Mid or Central projections for the LEEDS and GLA where variants are available. Figure 1 summarises the comparison in three bar charts. The first is for the whole TW region; the second depicts population change for WRZs outside London; the third compares results for Greater London (which has about a 90% overlap with the London WRZ). The projections jump off from different years: the Leeds projections use a mid-2011 baseline population; the GLA and EDGE projections use a mid-2015 baseline population; the ONS projections start with a mid-2014 baseline population. The bar charts show that these different starting points have minimal effect on future population. From 2021 onwards for both the whole TW region and Greater London, the LEEDS Mid population projects the highest populations. For WRZs outside London taken together, the EDGE projections produce the highest populations until 2045, the end point. The housing plans built into the EDGE projections imply more in-migration than under the trend migration assumptions of the other projections. Among the WRZs outside London, the Slough-Wycombe-Aylesbury (SWA) WRZ behaves like Greater London: the LEEDS projection is the highest because of the growth potential of the high ethnic minority population of Slough. In the 2011 Census, ethnic minorities constituted a majority of Slough's population. To conclude, capturing ethnic heterogeneity in the population makes a substantial difference to projected populations in areas of high ethnic diversity in 2011, i.e. the London WRZ or Greater London and the SWA WRZ. 5 Collaboration with ONS and other organizations 5.1 Consultation with ONS As one of our two external partners for the NewETHPOP project, we consulted with ONS in the initial design phase of the NewETHPOP project in 2014-15 and later made them aware of our results. ONS have recently released reports on their work on estimating ethnic group populations for LADs at each mid-year, based on survey and administrative data. They have invited comments on these outputs. The LEEDS team will compare ONS post-2011 estimates with the LEEDS projection results. Previously, ONS had used a roll forward method based on estimates of demographic rates by ethnicity up to mid-2009 but had discontinued the production of these estimates because of differences from estimates based on the Annual Population Survey. 5.2 Collaboration with Edge Analytics Our second external partner in the NewETHPOP project was EDGE Analytics. At their request, in the summer of 2017 we delivered full sets of our two publicly available projections. They intend, after re-formatting and quality assurance, to make available our baseline ethnic populations and component rates, as part of the POPGROUP software suite supported by the Local Government Association. 5.3 Project for Modern Britain In November 2016, we implemented an analysis for the Modern Britain Think Tank, based on our NewETHPOP results. This involves converting our projections from an LAD geography to Westminster Parliamentary constituencies for selected general election years (2015, 2020, 2025, 2030, 2035). The workbook of results was designed so that MPs and constituents could gain some idea of how the ethnic profile of their constituency will change. The assumption that General Elections occur on a fixed timetable was over-turned by Teresa May's decision to hold a June 2017 election. The Modern Britain Think Tank commissioned addition of 2017 ethnic populations by parliamentary constituency in November 2017. 5.4 Military and Police recruitment ONS have referred many enquiries to us from organizations wanting information on future ethnic population numbers. These included the British Army who wished to align their recruitment targets to number of young persons by ethnicity in recruiting regions and the Police College who were undertaking a similar investigation for future recruits to the Police Service. 5.5 Local Authority enquiries A number of local authorities have enquired about access to our 2011 based projection results. These include Salford, Glasgow and Essex Councils. Until the middle of the year, we referred them to the UK Data Archive deposit. From now on, we can also refer them to our online database. 6 Conclusions This report has outlined in narrative form the continuing impact that our work on the ESRC funded NewETHPOP project has had. We have a formidable product, nationally extensive projections of LAD-Ethnic Group sub-populations for the whole of the UK. We have demonstrated that such an endeavor can be implemented in the short time frame and resources provided by ESRC's Secondary Data Analysis Initiative (SDAI). We have made progress in dissemination through submission and publication of a set of further outputs. We have demonstrated that the NewETHPOP outputs can be employed to assist the UK's largest water utility in its strategic planning. This applied work has thrown up some formidable challenges but also revealed some vital features of our projections. Ethnic projections are under-taken by only a few National Statistical Offices and by fewer academic researchers. We hope in future when our writing plans are fulfilled, that more countries will take ethnic heterogeneity into account in their national and sub-national demographic projections. We believe ethnic heterogeneity will have effect increases the population of developed countries that are immigration destinations that parallel the effect that the introduction of education into demographic projections has had in decreasing fertility and lowering mortality in developing countries in work by Wolfgang Lutz and colleagues in their 2014 opus, World Population and Human Capital in the Twenty First Century (Oxford University Press). Table 1: Population projections implemented using the NewETHPOP software, component estimates and assumptions Projection Horizon Component assumptions Availability International Migration Internal Migration Fertility Mortality NewETHPOP International Migration Scenarios HIGH 2011-2061 Pre-Brexit 2010-2011 NPP2014 NPP2014 PR, PW MID 2011-2061 NPP2014 2006-2011 NPP2014 NPP2014 WD, WR, DS, PR, PW LOW 2011-2061 Slow decline 2001-2011 NPP2014 NPP2014 WD, WR, DS, PR, PW Demography Paper International Migration Scenarios HIGH-R 2011-2061 Pre-Brexit 2006-2011 NPP2014 NPP2014 NL, PW, PR MID-R 2011-2061 NPP2014 2006-2011 NPP2014 NPP2014 NL, PW, PR LOW-R 2011-2061 Fast decline 2006-2011 NPP2014 NPP2014 NL, PW, PR Thames Water Scenarios HIGH-TW 2011-2101 Pre-Brexit 2010-2011 NPP2014 NPP2014 PR, SC MID-TW 2011-2101 NPP-2014 2006-2011 NPP2014 NPP2014 PR, SC LOW-TW 2011-2101 Slow decline 2001-2011 NPP2014 NPP2014 PR, SC EFC-TW 2011-2101 NPP2014 2006-2011 Ethnic Convergence NPP2014 PR, PW Notes: WD= Website Database, WR - Website Repository, Website: http://www.ethpop.org DS = UK Data Service https://discover.ukdataservice.ac.uk/catalogue/?sn=852508&type=Data%20catalogue, Study Number SN852508 Authors: PR (Phil Rees) p.h.rees@leeds.ac.uk, PW (Pia Wohland) pwworkhyms@gmail.com, NL (Nik Lomax) n.m.lomax@leeds.ac.uk, PN (Paul Norman) p.d.norman@leeds.ac.uk SC (Stephen Clark) s.d.clark@leeds.ac.uk NPP = National Population Projections Table 2: Publications 2.1 Publications from the NewETHPOP project Rees P, Wohland P & Norman P (2017) The United Kingdom's multi-ethnic future: how fast is it arriving? Chapter 10, pp157-171 in J. Lombard, E. Stern, G.P. Clarke (ed.) (2015) Applied Spatial Modelling and Planning, Routledge, London. Clark S & Rees P (2017) The drivers of health trends: a decomposition of projected health for local areas in England. Chapter 2, pp.21-40 in Swanson D (ed.) Frontiers in Applied Demography. Springer. Rees P, Wohland P, Norman P, Lomax N & Clark S (2017) Population projections by ethnicity: challenges and a solution for the United Kingdom. Chapter 18, pp.383-408 in Swanson D (ed.) The Frontiers of Applied Demography, Springer. Wohland P, Rees P, Norman P, Lomax N & Clark S (2017) Bevölkerungsprojektionen ethnischer Gruppen in Großbritannien und Nordirland . Die räumliche Ausbreitung ethnischer Diversität. Pp.339-362 in Mayer T (ed.) Die Transformative Macht der Demografie. Springer, Wiesbaden. Rees P, Clark S, Wohland P, Lomax N & Norman P (2018) Using the 2001 and 2011 censuses to reconcile ethnic group estimates and components for the intervening decade. Chapter 2, pp.277-293 in Stillwell J (ed.) Routledge Handbook of Census Resources, Methods and Applications: Unlocking the UK 2011 Census. Routledge, Abingdon. Clark S, Birkin M, Heppenstall A & Rees P (2018) Using 2011 census data to estimate future elderly heath care demand. Chapter 23, pp.305-319 in Stillwell J (ed.) Routledge Handbook of Census Resources, Methods and Applications: Unlocking the UK 2011 Census. Routledge, Abingdon. 2.2 Publications in preparation from the NewETHPOP project Lomax N, Wohland P & Rees P (2018) The roles of international and internal migration in the spatial distribution of the UK's ethnic groups. Demography, in revision. Rees P, Norman P & Wohland P (2018) Development of an ethnic fertility convergence scenario. Population Studies, in draft. Rees P, Norman P, Lomax N & Wohland P (2018) The future ageing of Britain's ethnic groups. Australian Journal of Ageing, in draft. Rees P, Norman P & Durham H (2018) Future ethnic population of the UK's primary urban areas. Urban Studies, in draft. Rees P & Clark S (2018) Immigration to and emigration rom the UK: the numbers' game. Population, Space and Place, in draft. Rees P, Wohland P, Norman P, Lomax N, Clark S (2018) Britain's Ethnic Future: The Dynamics and Implications of Diversity. Book proposal to be submitted to International Population Studies series of Routledge. 2.3 Publications in preparation from the Thames Water project Nawaz R, Rees P, Clark S, Mitchell G, McDonald A, Lambert C & Henderson R (2018) Projections of domestic water demand over the long-term: A case study of the Thames Water region. Journal Water Resources Planning and Management, in revision. Rees P, Clark S, Wohland P, Kalamandeen M (2018) A comparison of sub-national population projection methods, assumptions and results: a case study of the Thames Water Region. Applied Spatial Analysis and Policv, in revision. Rees P & Clark S (2018) Projecting populations and households for subnational areas over the long-term: Application in water demand forecasts for Thames Water. Population, Space and Place, in draft. Note: Authors in bold are members of the NewETHPOP project team. Table 3: Presentations (1 September 2016 to 31 December 2017) Rees P, Wohland P, Clark S, Lomax N & Norman P (2016) The Future is Diversity: New Forecasts for the UK's Ethnic Groups. European Population Conference 2016, Johannes Gutenberg Universität, 31 August - 3 September 2016 Lomax N, Wohland P & Rees P (2016) Examining the roles of international and internal migration in the spatial distribution of the UK's ethnic group populations. British Society for Population Studies, Annual Conference, University of Winchester, 12-14 September 2016. Norman P (2016) Effects of international migration on the age structure of young persons: local authorities in England, 2001 to 2011. British Society for Population Studies, Annual Conference, University of Winchester, 12-14 September 2016 Wohland P (2016) Ethnic mortality estimation - a method put to the test. British Society for Population Studies, Annual Conference, University of Winchester, 12-14 September 2016 Wohland P (2016) Mortality, ethnicity and nativity in England and Wales-do we see a healthy migrant effect? Society for Social Medicine, University of York, 14-16 September 2016 Rees P, Lomax N, Norman P, Wohland P & Clark S (2017) What would we like to know about the future? Alternative approaches to sub-national population projections. BSPS Day Meeting on UK Variant Sub-National Population Projections and Population Projections by Ethnicity, University of Leeds, Monday 27 March 2017. Rees P (2017) Immigration to (and emigration from) the UK: the numbers' game. Paper presented at the Launch Event for the Institute of Advanced Studies at Loughborough University. Friday 9th June 2017 Rees P, Nawaz R, Clark S, Henderson R, Lambert C, Corr B, Mitchell G, Wohland P & McDonald A (2017) Forecasting water demand under policy scenarios for a UK water company, 2011 to 2101. Paper presented at the Regional Science Association International, British and Irish Section, 46th Annual Conference, Crown Hotel, Harrogate, 24 August, 2017 Rees P (2017) Ethnic population projections for sub-national areas: Resources, Results, Reflections. Paper presented at the POP GROUP User Group Meeting, The Studio, 7 Cannon Street, Birmingham, Wednesday 6 December 2017 Rees P (2017) Forecasting water demand under policy scenarios for a UK water company, 2011 to 2101. Paper presented at a CSAP Seminar, School of Geography, University of Leeds, Tuesday 12 December 2017 Note: Authors in bold are members of the NewETHPOP project team. Table 4: Reports from the Thames Water project Project reports Rees P, Inception Report, June 2016 Rees P, Nawaz R & Clark S, Progress Report 1, October 2016 Rees P, Nawaz R, Clark S, McDonald A & Wohland P, Progress Report 2, November 2016 Rees P, Nawaz R, Clark S, McDonald A & Wohland P, Final Report, Phase 1, January 2017 Rees P, Nawaz R, Clark S, Kalamandeen M, McDonald A & Mitchell G, Progress Report on Phase 2, March 2017 Rees P, Nawaz R, Clark S, Kalamandeen M, McDonald A & Mitchell G, Final Report, Phase 2, May 2017 Rees, P, Norman P, Wohland P, Clark S and Nawaz, R, Follow on Report, September 2017 Table 5: Projected populations for all Thames Water WRZs, 2011 to 2101 Projection Populations (1000s) Time Series (2011=100) Ethnic Grouping 2011 2041 2071 2101 2011 2041 2071 2101 HIGH-TW IPB Total 808 1,722 2,790 3,814 100 213 345 472 NIPB Total 7,889 11,459 14,321 14,506 100 145 182 184 Total 8,697 13,181 17,111 18,321 100 152 197 211 MID-TW IPB Total 808 1,632 2,556 3,430 100 202 316 425 NIPB Total 7,889 10,933 12,991 12,662 100 139 165 161 Total 8,697 12,566 15,547 16,093 100 144 179 185 LOW-TW IPB Total 808 1,575 2,130 2,349 100 195 264 291 NIPB Total 7,889 11,121 11,578 8,718 100 141 147 111 Total 8,697 12,696 13,709 11,068 100 146 158 127 Notes: WRZ = Water Resource Zone, IPB = Indian, Pakistani, Bangladeshi, NIPB = Not IPB = Other Ethnic Groups Source: Leeds NewETHPOP model used in a project for Thames Water Figure 1: Comparison of the LEEDS Mid projection with alternatives, 2011 to 2061 Notes: LEEDS = NewETHPOP team; GLA = Greater London Demographic Intelligence ONS = Office for National Statistics; EDGE = Edge Analytics MID = Middle Projection aligned to ONS Principal National Population Projection assumptions (2011 Based) CENTRAL = Average of GLA Short-term and Long-term Projections (2015 Based) SNPP = Sub-National Population Projection (2014 Based) EDGE HOUSING = Population projections for TW WRZs based on Housing Plans and ONS SNPP
First Year Of Impact 2016
Sector Communities and Social Services/Policy,Environment,Healthcare,Other
Impact Types Societal,Economic,Policy & public services

Description Long-term Population and Property Forecasts for Thames Water
Geographic Reach Local/Municipal/Regional 
Policy Influence Type Membership of a guideline committee
Description Long-Term Population and Property Forecasts for Thames Water
Amount £111,250 (GBP)
Funding ID University of Leeds KRISTAL # 107613 
Organisation Thames Water Utilities Limited 
Sector Private
Country United Kingdom
Start 04/2016 
End 09/2017
Title Local Ethnic Population Projection 
Description A model has been developed for forecasting sub-national populations classified by ethnicity. The model uses a version of the cohort-component method called bi-regional. The bi-regional model uses internal migration rates between each spatial unit and the rest of the country. This is helpful in computing future populations by 101 ages, 2 genders, 12 ethnic groups and 389 local authorities (4,680 sub-populations by 202 age-gender categories. The software is written in the R language. 
Type Of Material Improvements to research infrastructure 
Provided To Others? No  
Impact Our method has been adopted by other researchers also handling very large "state-spaces". For example, Guy Abel used a bi-regional model for projecting world country populations in World Population and Human Capital in the Twenty-First Century (edited Lutz W, Butz W and KC S (ed) (Oxford University Press, 2014) 
Title ETHPOP Database and Repository 
Description The results of two projections of UK local authority-ethnic group populations are provided: (1) in an online database which uses can select small subsets of interest and download those extracts (2) in a repository of zip archive files which can be selected and downloaded (3) in a large zip archive of all outputs deposited at the UK Data Archive as SN 852508 NEWETHPOP - Ethnic population projections for UK local areas 2011-2061 (see ;http://reshare.ukdataservice.ac.uk/852508/) 
Type Of Material Database/Collection of data 
Year Produced 2017 
Provided To Others? Yes  
Impact Our online database has been used by local authorities interested in the future composition of their populations by ethnicity, by the British Army and the Police Service interested in matching their recruitment with local ethnic population profiles. We are talking to the Office of National Statistics about using our projections as a comparator dataset for their Administrative Census project which is estimating local populations by ethnicity using administrative and survey data. We have used our database intensively in a project for Thames Water Utilities Ltd in a project for forecasting water demand for the TW Water Supply region, from 2011 to 2101 
URL http://www.ethpop.org
Description EDGE ANALYTICS LTD, Leeds 
Organisation EDGE Analytics Limited
Country United Kingdom 
Sector Private 
PI Contribution EDGE Analytics is a consultancy company that delivers research to UK Local Authorities and companies. We have supplied them with the inputs to and outputs from our two main ethnic population projections. They will re-process the estimates and assumptions for fertility, mortality, internal migration and international migration by ethnicity, so they can be used in the POPGROUP software for projecting local authority populations. This system is owned by the Local Government Association and EDGE maintain and disseminate the software (EXCEL based) to local authority, devolved administration and private company clients.
Collaborator Contribution See above. The contribution is to re-purpose our inputs and outputs for use by local authorities
Impact EDGE plans to complete the re-purposing of our inputs and outputs in 2018.
Start Year 2015
Organisation Thames Water Utilities Limited
Country United Kingdom 
Sector Private 
PI Contribution Thames Water invited the School of Geography at the University of Leeds to deliver projections of the populations and households in the Thames Water supply region. Our expertise in ethnic population projection was considered an essential input to Thames Water's strategic assessment of future water demand. Prior work has shown that there were clear differences between ethnic groupings in their domestic consumption of water. Our research using Thames Water's Domestic Water User Survey data established that the difference in per capita consumption between households with an Indian, Pakistani and Bangladeshi head (household representative person) and households with heads in other groups was 50 litres per day. As an input to Water Demand Forecasts we used our two NewETHPOP projections (1) a MID projection aligned to ONS assumptions and (2) a LOW projection aligned to ONS assumptions but with different assumptions for international migration reflecting lower net international migration under Brexit). We added a third projection to these two that assumed a HIGH net international migration flow, as observed in 2015-2016. The projections were extended from an end date of 2061 to an end date of 2101, to meet Thames Water's strategic planning objectives.
Collaborator Contribution Thames Water asked us to extend our projections to 2101 from 2061. Such long-term sub-national projections have not been implemented by the Office for National Statistics (ONS) nor by the Greater London Authority (GLA) with respective end dates on 2039 and 2050. Thames Water asked us to develop household projections from the population projections and provided intensive feedback on our model for household water consumption by occupant number, property type and ethnicity. We have submitted a paper on this work to the Journal of Water Resource Management. Thames Water asked us to compare our projections with those of ONS, GLA and EDGE Analytics (a consultancy contracted to deliver property based projections to 2045). This comparison showed that our projected populations out to 2050 were higher than those of the other organizations for two TW Water Resource Zones: the London WRZ and the Slough-Wycombe-Aylesbury WRZ, but were lower for the other 4 WRZs outside London produced by EDGE. Our projections were higher for WRZs with high ethnic diversity, reflecting the higher growth potential of ethnic minorities compared with the majority White British and Irish group. Our projections were lower for WRZs with low (though increasing) ethnic diversity because our internal in-migration projections based applying recent internal migration rates were lower than the in-migration associated with local authority housing plans projected by EDGE.
Impact We are in process of writing up the following papers from journal publication: Nawaz R, Rees P, Clark S, Mitchell G, McDonald A, Lambert C & Henderson R (2018) Domestic Water Demand in the Thames Region: A Model for Use in Preparing Long-Term Projections. Submitted to Water Resources Management. Nawaz R, Rees P, Clark S, Mitchell G, McDonald A, Kalamandeen M, Lambert C & Henderson R (2018) Long Term Domestic Water Demand Projections for London and the Thames Valley. In draft, target journal Water Resources Management. Rees P, Clark S, Nawaz R, Lambert C & Henderson R (2018) Projecting populations and households for subnational areas over the long-term: Application in water demand forecasts for Thames Water. In draft, target journal Applied Spatial Analysis and Policy. Rees P, Clark S, Wohland P, Kalamandeen M, Boden P, Jasinska M, Tonkins W, Corr B, Lambert C & Henderson R (2018) A comparison of sub-national population projection methods, assumptions and results: a case study of the Thames Water Region. In draft, target journal Population, Space and Place. Rees P, Norman P & Wohland P (2018) Development of an Ethnic Fertility Convergence Scenario. In draft, target journal Population Studies. This collaboration involves population geographers (Rees, Boden), computer scientists/statisticians (Clark, Tonkins), environmental scientists (Nawaz, Kalamandeen), environmental geographers (McDonald, Mitchell), water managers (Lambert, Henderson), demographers (Corr).
Start Year 2016
Title NewETHPOP: software for projecting local authority-ethnic group populations 
Description See Research Tools and Methods R code for implementing a bi-regional cohort-component model for a large set of sub-populations 
Type Of Technology Software 
Year Produced 2016 
Impact The software with associated inputs was used to project local authority-ethnic group populations for the whole UK (see www.ethpop.org). The software was used to extend the NewETHPOP projections to 2101 as part of a project on future water demand undertaken for Thames Water Utilities Limited