You asked
Can you please provide details as to how many surveys are undertaken each year where a voucher is provided to the participants as a "thank you". Please state the number of surveys and the number/monetary value of vouchers.
Can you advise on the following;
The number of people mailed for each survey
The level of participation/respondents to each survey
The costs of vouchers mailed out - face value and cost to buy
The number and value of vouchers encashed
Can you advise the balance of unused vouchers that you currently hold.
Can you advise why you send the voucher with the letter asking for participation in the survey rather than following the person participating in the survey?
We said
Thank you for your request.
The use of incentives to improve response is common practice among all survey organisations. We consistently work hard to ensure high response rates on our surveys (including using incentives) as low response rates increase the number of risks. Specifically:
A survey with a low response rate may simply have too few data points to meet the requirements of the subsequent statistical analysis. For example, the 2016 National Statistics Quality Review on the Living Costs and Food survey concluded that the declining number of data points had implications for the precision of key statistical outputs and that action needed to be taken to increase response rates.
Falling response rates increase the risk that the survey is biased, i.e. not representative of the population being sampled.
Lower response rates decrease stakeholder confidence in the survey and increase the risk that the outputs, analysis and conclusions based on the survey are challenged.
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 in the form of a paper voucher or book of stamps. This is unconditional because it is sent 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. Depending on the value of the incentive and the type of survey unconditional incentives are cost effective when compared with alternative approaches for achieving increases in response (i.e. 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.
The following table summarises how incentives are used for our funded surveys as well as the sampled households and the household participation rates for 2017/18. This includes our following funded surveys; Wealth and Assets Survey (WAS, known as Household Assets Survey to households in the UK), Living Costs and Food Survey (LCF), Labour Force Survey (LFS) and Survey into Living Conditions (SLC).
| Survey | Incentive | Sample Size | Participation Level |
|---|---|---|---|
| WAS | WAS First InterviewUnconditional£5 Shopping Voucher (Paper)Conditional£10 Shopping Voucher (Paper or electronic, the household decide which they would like to receive)WAS Follow-up Interviews UnconditionalNoneConditional£10 Shopping Voucher (Paper or electronic, the household decide which they would like to receive) |
15,655 | 58.4% |
| LCF | UnconditionalBook of 2nd class stamps sent with advance letter ConditionalAll household members who are interviewed and complete a full diary for the full two weeks qualify for the shopping voucher (Paper or electronic, the household decides) as follows: Adult - £20.00 Child - £5.00 (children aged 7 – 15 only) |
13,066 | 42.59% |
| LFS | LFS First Interview and Additional Sample BoostUnconditional50% of the sample receive a £5 paper shopping voucher and 50% receive a £10 paper shopping voucher as part of an on-going trial to determine the most cost-effective unconditional incentive. |
80,963 | 56.16% |
| SLC | SLC First InterviewUnconditionalBook of 2nd class stampsSLC Follow-Up Interviews Conditional£10 Shopping Voucher (Paper or electronic, the household decides) |
20,093 | 57.54% |
Fulfilment of our shopping voucher requirements is actioned by two outside companies, one for the paper vouchers (using the Love2Shop scheme) and one for the electronic E-Voucher. We only hold a small amount of the £10 and £5 paper vouchers and no electronic E-Vouchers. As of 23.05.2018 the amounts were 872 x £5 and 143 x £10.
In 2017/18 the cost of each type of incentive was as follows:
| Face Value | Cost to ONS | Number sent | Total Cost | |
|---|---|---|---|---|
| Paper Vouchers (Love2Shop) | £10 £5 |
£9.95 £5.23 |
89,655 62,629 |
£892,067 £327,550 |
| Electronic E-Voucher | £10 £5 |
£10.50 or £0.50 if not redeemed £5.50 or £0.50 if not redeemed |
2,797 | £32,485 |
| Stamps | £3.08 | £3.08 | 18,838 | £58,021 |
As part of our continued efforts to improve the efficiency of our operation we have recently been exploring alternative voucher schemes with our suppliers. At present, our current contract with the paper voucher (Love2Shop) supplier means we must pay for all unconditional vouchers sent out, regardless of whether they are used. We have now negotiated a new contract that means from this summer we will only pay for those paper vouchers that are spent by households.