Survey invitations, responses and incentives over the last 12 months

FOI reference: FOI-2026-3543

You asked

I am interested in letters sent out to the people of the UK asking them to complete surveys, such as the 'Play My Part' survey currently underway.

Can you please advise the following:

1. How many people or households have been asked to take part in any study in the past 12 months? Please break this down into England, NI, Wales, and Scotland if possible
2. What percentage of households have responded to such requests over the past 12 months
3. How much has been spent on rewards for completing the study, including but not limited to vouchers, gift cards, notepads

We said

Thank you for your request.  

Regarding questions 1 and 2, please see the associated spreadsheet containing the information requested.  

Regarding question 3, the amount spent on incentives in total was £6 million. This includes all types of incentive.  

Please note the following. 

The data include ONS-owned surveys only. These are: Labour Force Survey (LFS), Living Costs and Food Survey (LCF), Household Assets Survey (HAS), Opinions Survey (OPN), and Transformed Labour Force Survey (TLFS). 

The percentage of households that have responded is calculated as the number of responding addresses divided by the sample size. This is not the same as an official response rate, which takes into account other factors such as ineligible households like holiday homes.  

The number of households invited to take part is the number of sampled addresses. This is the number of households that have been sent a letter inviting them to take part, some of which involve an interviewer subsequently following up with contact, some of which do not.   

TLFS is a developmental survey and has undergone some significant sample size and design changes over the period in question, therefore sample sizes may not be representative of future samples.  

The OPN sample is partially constructed from TLFS respondents, meaning some addresses or households have been invited to participate in two different surveys. Therefore there will be some households that are double counted in the figures given.  

We use incentives in two different ways to improve response and encourage respondents to participate in our surveys. In the first instance we send an unconditional incentive to all sampled households, regardless whether they respond or not. Controlled research studies by ourselves and others consistently demonstrate that the most effective way of increasing response to household surveys is by using such unconditional monetary incentives. Unconditional incentives are cost effective when compared with alternative approaches for achieving increases in response (that is, the cost of extra visits in person by interviewers to households to secure an interview). 

To encourage participation and as a token thank you for taking part, we also use conditional incentives, given to a respondent after they have completed the survey. This is particularly useful to surveys such as the Living Costs and Food Survey that require the respondent to keep a diary of their expenditure and is therefore quite time consuming. Research studies show that conditional incentives have a positive impact on response rates, although not as large as for unconditional incentives. 

Our incentives are typically e-vouchers, which are time bounded and expire. As part of our continued efforts to improve the efficiency of our operation, our contract with our supplier means that a large proportion of the value of any unclaimed e-vouchers is returned to the ONS, to ensure value for money for the taxpayer.