|Date:||01 March 2010|
A report of research carried out by Institute for Fiscal Studies on behalf of the Department for Work and Pensions. This Appendix provides a detailed and formal derivation of the estimation
methods considered in the main report, as well as of the conditions for their validity. This Appendix was written as a stand-alone, avoiding the need to constantly refer the reader to the main report. There will thus necessarily be some overlap and repetition with the main report.