Page 312 - Special Topic Session (STS) - Volume 3

STS547 Owen A.
Figure 1. Proposed Transformation of Population Statistics in England
and Wales

This is an ambitious undertaking with many challenges. Research to date
has established that population size estimates for local government areas can
be derived from administrative sources alone, but the quality varies and is
poorer at lower levels of disaggregation. Those quality problems are driven by
administrative data lags, resulting in both under-coverage and significant
over-coverage. From a methodological perspective, this is the largest
challenge. ONS has extensive experience of dealing with under-coverage (in
censuses), using a focused coverage survey and capture-recapture techniques
(Brown et al, 2018). Dependent interviewing, where a sample of administrative
records are drawn and traced in the field, is in theory the best way of
estimating over-coverage. However, due to ethical concerns, only dependent
sampling (where you can sample but not use data in the field) is being
considered. Thus, ONS is currently exploring the options for estimating
population size using some form of capture-recapture.
The expected sources of data for estimation include administrative data
sources and a population coverage survey designed for the purposes of
estimating population size, much like a Post-enumeration Survey.

2. Methodology
2.1 Traditional Dual-system Estimation
Dual-system estimation (DSE) is an established and understood technique
when applied to measuring population size from Censuses. In the UK it has
been used successfully in the 2001 and 2011 Censuses to derive the key
population estimates. It will also be used, albeit in a log-linear modelling form,

301 | I S I W S C 2 0 1 9