Wednesday 5th March 2014 - Joint meeting with the RSS Social Statistics Section

Phil Rees - Professor of Population Geography, School of Geography, University of Leeds, Leeds [Presentation]

How confident can we be in the projections of the older population of the United Kingdom?

This paper responds to a request by Lord Filkin, the Chair of the House of Lords Select Committee on Public Service and Demography which produced the influential report, Ready for Ageing, to supply an assessment of confidence in the projected numbers of older persons for the UK. The paper reviews methods for establishing confidence through probabilistic projection and recent probabilistic projections for the UK carried out by official statistical agencies and by academics. However, none of these sources deliver reasonable confidence intervals. To meet the Select Committee’s request, an alternative method is proposed that uses a set of plausible projections of the UK population to deliver intervals for age-specific populations with known probabilities. Nineteen projections were pooled to compute confidence intervals around a median projected population for each five year age group. The UK population aged 65 and over, 10.2 million in 2010, is projected to be 18.3 million in 2050, with a 95 percentage confidence that the population will lie between 21.3 and 15.7 million. We can be more confident about the numbers for the younger old (aged 65-84) than for the older old (aged 85+). However, we cannot be very confident about the future number of centenarians. This population is projected to be 242 thousand in 2050 compared with 12 thousand in 2010 but the 95 percentage confidence interval stretches from 426 thousand to 59 thousand. The final part of the paper discusses how much confidence we can have in the confidence interval estimates and reports results by Nico Keilman (University of Oslo) who kindly re-ran his Uncertain Population of Europe projections to generate confidence intervals based on a large number of simulations of the national population, drawing assumption parameters from historical error distributions.

Ready for Ageing report: http://www.parliament.uk/business/committees/committees-a-z/lords-select/public-services-committee/report-ready-for-ageing/

The meeting will be held in Room 9.27, Level 9, Worsley Building, University of Leeds. Starting 4pm until 5pm with Teas/Coffees available from 3:30pm.