<p>The Employment Retention and Advancement (ERA) study is a large-scale randomised evaluation that was run in six UK regions between October 2003 and October 2007 to test the effectiveness of an innovative package of support for individuals starting the New Deal 25 Plus (ND25+) or the New Deal for Lone Parents (NDLP) programmes.</p><p>The aim of this report is to explore how the four-year findings from the experimental research relate to the impacts that would have been experienced, on average, by all the people who were eligible for ERA, had they participated in the programme. (Please note that a full ERA evaluation report looking at the five-year impacts, as well as at the costs and benefits associated with the programme will be published by the Department for Work and Pensions (DWP) during spring 2011.)</p><p>Overall, the findings either validate the four-year interim experimental results of the main ERA evaluation or indicate that the ERA intervention would have been even more effective for its full eligible population than it was for its actual participants. Specifically, for the ND25+ group the experimental impacts on earnings appear to be representative of the impacts that the full eligible ND25+ population would have experienced under ERA. The experimental findings on employment are, however, found to actually underestimate, by over one-third, the gains that the ND25+ eligible population would have enjoyed under ERA.</p><p>A similar story emerged for the NDLP group, but in terms of different outcomes. The NDLP eligible population would have experienced the same (zero) impact as the participants in terms of employment. However, the eligible population would have experienced a significant and positive increase in earnings instead of the absence of any significant impact as experienced by the study participants.</p>