Data services

Tender description

Background The Office for National Statistics (ONS) is working towards the transformation of the population, migration and social statistical system, currently based on either a full population census and/or intercensal surveys, to better meet the needs of our users. This work is being conducted as part of the Census and Data Collection Transformation Programme (CDCTP) which seeks to rebalance ONS’s data collection activity significantly toward wider, more integrated use of administrative and other non-survey data sources, thereby reducing our reliance on large population and business surveys. While this approach will not eliminate the need for surveys, it does mean ONS’s traditional approach to surveys is likely to change. The expectation is that in the future, instead of serving as the primary sources of data residual surveys will be needed to support the administrative data first approach, helping to assess the quality of administrative data and fill in the gaps that this data can’t provide. Research undertaken so far has also demonstrated that a new continuous population coverage survey (PCS) to measure and adjust for coverage biases in the administrative data to be used in the transformed population and migration statistical systems will be required. When live and at scale the PCS would require an annual issued sample of circa 500 000 households. To support this transformation, ONS is working towards the development of an Integrated population and characteristics survey (IPACS). The IPACS will consist of a large scale ‘Wave 1’ household survey which integrates data collection requirements to support the transformed population and migration statistical system (including PCS data) as well as key Labour Market estimates (currently collected via the Labour Force Survey). Collection will be online first, with face-to-face or telephone interviews for those who do not complete online. The model will also include longitudinal follow up (waves 2 to 5) for Labour Market requirements, as well as additional topic-based submodules at wave 2. The delivery of the IPACS requires extensive testing and a series of iterative tests have taken place over the last 2 years to further develop understanding of communication and incentive strategies, to examine online response rates, and to provide data which can be used to compare labour market estimates from the redesigned survey model to the existing LFS data. These tests build evidence towards the feasibility of the IPACS. The next stage of testing is a full parallel run of the IPACS design which will test both the operational and statistical viability of the model. The data collected will also be part of the evidence base used by ONS when making a recommendation to the UK government in 2023 about the future of population and housing censuses in England and Wales. ONS would like to commence the IPACS parallel run in mid-2020 and expect data collection to continue for at least an 18-month period, although this may be extended. Over the whole of this 18-month period we expect to issue a sample of approximately 160 000 households at wave 1 following up a substantial proportion at subsequent waves. It is likely that in any quarter when there are 5 waves being issued the total sample size would be approximately 100 000 although this will be mixed mode. At wave 1 we expect data collection to be online and face-to-face (and possibly postal) and we expect the majority of data collected at waves 2 to 5 to be online and via telephone, with minimal face-to-face interviewing. Our long-term strategic vision when IPACS is fully operational with an issued wave 1 sample of 500 000 households per annum, is to deliver data collection via a partnership arrangement between ONS’s Social Survey Operations Division and one or more suppliers from the market. For the parallel run we also anticipate a partnership arrangement although we may require full market provision of field capacity initially, and therefore anticipate publishing an invitation to tender for the delivery of the IPACS parallel run later in 2019/20.