September 2013 marks the release of NIDS Wave 3. During the production of Wave 3 data certain information came to the fore that required changes to the Wave 1 and Wave 2 datasets. Fieldwork being a process of continuous improvement, enhanced processes employed during Wave 3 have resulted in more accurate information. In some cases we managed to interview respondents whom we previously did not interview because of lack of availability or difficulties in locating the households. We used this information to update previously collected information in both Wave 1 and Wave 2 data. Furthermore, new variables were added.
Some of the changes necessitated a recalculation of the weights. At the same time, the weights were also calibrated to the latest mid-year population estimates.
Important: We highly recommend users download the latest Wave 1 and Wave 2 datasets, especially if it is to be used in conjunction with Wave 3. Every effort was made to ensure that the latest datasets are internally consistent and we believe this release carries the best information.
Secondly, we advise users to carefully review their do-files, especially changes made to specific records. For reasons described below the identifier might have changed and/or the underlying data might have been cleaned.
This document summarises the changes to the Waves 1 and 2. It is predominantly aimed at users who previously used NIDS datasets to help them understand what is different in the latest release. We encourage all users to reference the User Manuals for more detail about the methodology and details of data collection.