This Department for Work and Pensions (DWP) statistical notice advises users of a change in methodology for measuring uncertainty in future:
- Households Below Average Income (HBAI) statistics
- Pensioners’ Income Series (PI) statistics
This change will take effect for the 2015/16 publication, pre-announced for publication at 16 March 2017.
The new methodology provides an improved measure of uncertainty around key HBAI and related PI estimates by:
- creating resamples of the HBAI dataset by simulating stratified, cluster sampling for Great Britain (GB) and stratified sampling for Northern Ireland (NI)
- creating a unique set of grossing factors for each resample using the HBAI grossing process to gross the GB and NI resamples to the United Kingdom (UK) population
The old methodology used a simpler technique of creating simple random resamples of the UK HBAI dataset and re-using the original HBAI grossing factors.