International migration is now a significant driver of population change
across Europe but the methods available to estimate its true impact upon
sub-national areas remain inconsistent, constrained by inadequate systems of
measurement and data capture. In the absence of a population register for
England, official statistics on immigration and emigration are derived from a
combination of survey and census sources. This paper demonstrates how
administrative data systems such as those which capture registrations of recent
migrants with a local doctor, National Insurance Number registrations by
workers from abroad and the registration of foreign students for higher
education, can provide data to better understand patterns and trends in
international migration. The paper proposes a model for the estimation of
immigration at a local level, integrating existing national estimates from the
Office for National Statistics with data from these administrative sources. The
model attempts to circumvent conceptual differences between datasets through
the use of proportional distributions rather than absolute migrant counts in
the estimation process. The model methodology and the results it produces
provide alternative estimates of immigration for consideration by the Office
for National Statistics as it develops its own programme of improvement to
sub-national migration statistics.