Small business survey: linking 2006 and 2007 waves to the IDBR

This report describes work to link two waves of the Small Business Survey (SBS) to the Inter-Departmental Business Register (IDBR)1. The first is the Annual Small Business Survey 2006/07, hereafter SBS 2006; the second is the survey for 2007/8, hereafter SBS 2007. The linking work has been undertaken by Belmana and Middlesex University; IFF Research conducted both surveys and has overseen this work.
The focus of this research was to understand the strengths and weaknesses of different methods of linking and then develop an approach for application to the 2006 and 2007 waves of the survey. A particular difficulty, as older waves of SBS are linked to the IDBR, is the changes to businesses that would have occurred since the survey. This work has taken steps to reduce the effect of the age of the survey on the quality of the data linking, by linking to historic vintages of the IDBR and the Companies House register.
The report also reviews earlier work by the Office for National Statistics (ONS) linking the 2010 and 2012 SBS surveys to the IDBR. The project draws on insights from this, but introduces new linking methods that improve link rates. Various quality checks have been undertaken and, given the surveys were conducted almost a decade ago, the ability to link a higher proportion of respondents to the IDBR than achieved for the 2010 survey indicates the linking of SBS can be undertaken even for relatively old waves. Some preliminary analysis of the linked survey data suggests that there is potential for understanding the more long-term outcomes for businesses and correlating these with SBS responses.