In message ,
Martin Underwood writes

When people emigrate (if that is the explanation for the shortfall) is there
any official record of that fact?

No. Figures for emigration are estimated from surveys. People go abroad
for a visit, like it and stay ... this is much easier for young men
without families, hence that particular demographic shortfall.

If the number of UK citizens who emigrated
correlates with the shortfall, that looks a plausible explanation.

Emigration is believed to be the reason:

http://www.statistics.gov.uk/census2...plications.asp


--
Paul Terry