Why can't we get rid of the census?

The main ways of producing population statistics internationally include census type of approaches (short-form, rolling census), surveys and use of administrative sources. The Beyond 2011 Programme will investigate all these approaches and does not rule any out at this early stage...

Some data that might work is: the Council tax register, the Electoral roll, a register of patients using the NHS, Child benefit, pupils registered in schools and pension claimants data.

-Census 2011: can we do without it?