Scottish Employer Perspectives Survey 2021: Technical Report

Sampling

Sampling population and survey sampling unit

Establishments were used as the sampling unit for the survey, as opposed to an organisation-based approach. "Establishments" denote specific individual sites or premises; thus if an organisation has several sites, it is possible that more than one of these sites will have appeared in the sample. This approach has been chosen because it is at the establishment level where respondents are most likely to be able to provide a detailed and accurate picture of how employers go about meeting their skills needs. Decisions around training staff are often based on the training offer available in the local area, while recruitment also tends to occur at a more localised level. This approach has been used in the EPS series, and the Employer Skills Survey (ESS), since each series began.

The sampling population used for the Scottish EPS encompassed establishments across the full geographical spread of Scotland, in all sectors of the economy (across the commercial, public and charitable spheres). All Scotland establishments with two or more people working at them (including partners and working proprietors) were eligible for the survey – i.e. establishments with a single person on the payroll were excluded. This again mirrors the approach adopted in previous EPS and ESS surveys since 2012. The rationale for the inclusion of sites with two or more working proprietors is based on both practical and conceptual considerations.

From a conceptual viewpoint, the focus of the skills surveys is on the workforce, and as such any establishment covered logically needs to have staff (or the desire / potential to employ staff in the future). In this iteration of the survey, the survey covered employers' approaches to recruiting (particularly young people and education leavers), their engagement with apprenticeships and their facilitation of training staff to Vocational Qualifications. Findings from the survey can then be used to enhance employers' engagement with, and experience of, various recruitment and people development initiatives. Accordingly, the survey was aimed at those for whom such initiatives carry relevance (i.e. establishments with at least one employee).

On a more practical level, however, it tends to be much easier for survey respondents to think in terms of the overall 'headcount' for their site – including both working proprietors and employees – than to split out the two groups (particularly when the lines between the two are not clear-cut). For example, it is typically easier for employers to answer about recruitment channels for all managers / staff, rather than 'only those managers who are not working proprietors'.

The survey also excluded the self-employed (with no employees), as the question approach / context for this group would need to be somewhat different, since they are by definition not "employers". Additionally, there is an absence of robust population figures for this group, providing obstacles for robust and representative sampling and weighting.

The respondent sought at each establishment was the person who had most responsibility for staff issues such as training, recruitment or resourcing. For smaller establishments this was most often the general manager or owner, and for larger establishments this was most often the HR manager.^[1]

Sampling considerations for the 2021 survey

The key change to the 2021 survey was a reduction in the overall target sample size, from 2,650 interviews (in 2019) down to 1,000 interviews. This change has increased the margin of error to +/-3.1, compared with +1.9 in the 2019 survey.

In order to provide robust subgroup analysis (by minimising the margin of error), the usual 12 sector and 7-sizeband categories were collapsed for weighting and reporting purposes. The 7-sizeband breakdown was reduced to 6 sizebands by merging the 100-249 and 250+ sizebands into a single 100+ sizeband. To note, in previous EPS, the 100-249 and 250+ sizebands were weighted separately, but grouped into a 100+ sizeband for reporting purposes.

To collapse the sector groupings, a 6-sector grouping was created. Table 1 shows how the original 12-sector grouping maps to the 6-sector grouping. The 6-sector grouping has been used as an alternative sector breakdown in previous iterations of both ESS and EPS, however in the case of EPS, it should be noted that the 'Communications' subsector, which would have previously been sampled and weighted alongside the 'Transport' and 'Storage' sectors, ends up in a different category to these two subsectors under the new grouping.^[2]

Sampling approach and setting quotas

Although, as discussed above, 6-size and 6-sector groupings were used for weighting and reporting purposes, initial sampling calculations used the more granular ESS 13-sector by 7-sizeband breakdown of the IDBR population, and sample was ordered on this basis to maximise the representativeness of the sample. The ESS sector breakdown was used as it provided better alignment with the final 6-sector breakdown, by separating 'Transport and Storage' and 'Communications'.

Matching the previous iterations of the survey, the Scottish EPS 2021 adopted a disproportionate stratified random sampling strategy such that the quota targets set intentionally oversampled some groups and under sampled others, rather than setting targets in direct proportion to the business population. In practice this meant that some smaller sub-groups of employers (such as large establishments) were oversampled to ensure that a sufficiently large number of interviews were achieved to allow for robust sub-group analyses.

The process taken for Scottish EPS was as follows:

• Target interviews were stratified against a two-dimensional sector by size grid (13 sectors and seven sizebands) on an interlocking basis;
• The initial allocation of interviews was done according to employer sizebands, using a set of ratios that deliberately over-sampled larger employers;
• Interviews were then allocated to sector within each sizeband in proportion to their representation within the business population; and
• The starting sample was then drawn from the commercial data supplier, Market Location.

Population statistics used to stratify the business population were established through the March 2021 Inter-Departmental Business Register (IDBR), which was the latest available at the time. The IDBR is administered by the Office for National Statistics (ONS), it holds records of all businesses registered for VAT and all businesses operating a pay as you earn (PAYE) income tax scheme. The IDBR is widely regarded as being the most accurate and comprehensive 'official' source of business population data available, and was used for sampling and weighting in all previous editions of the EPS.

Sizeband quotas

In line with the approach utilised in the Scottish EPS 2019 survey, quota targets based on establishment size were set within each region by distributing interviews in each sector into six sizebands (see Table 2). This was achieved by utilising a set of selected ratios that struck a balance between over-sampling larger employers (relative to the unit population) whilst not skewing the size profile too far away from smaller establishments.

Larger establishments were oversampled in order to maximise the proportion of the workforce covered by the survey and because interviews in the largest sizebands have historically proven more difficult to complete. This also ensured that a sufficiently large number of interviews were achieved to allow for robust sub-group analyses. This oversampling of larger establishments was corrected when weighting the survey results (as detailed later in this technical report).

Sector quotas

Sector quotas were defined after setting interview targets by sizeband. Interview targets within each sizeband were allocated by sector according to the proportion of the employer population within each sizeband.

Adopting such an approach ensured the maximum Standard Error associated with findings by sector were minimised, in order to report with a greater level of confidence in the results.

Critically, this also helped to ensure that within each broad sizeband and sector, key cuts of the data were associated with sufficiently robust base sizes.

Table 3 shows the final sectors by size targets.

Regional targets

Mirroring the approach of previous EPS surveys, interviews were allowed to fall out 'naturally' by geography within Scotland. For the analysis and reporting Regional Outcome Agreement (ROA) areas have been used (how the ROAs are defined in terms of Local Authority is presented in Appendix C). The expected distribution by ROA is shown in Table 4. The 'expected 'fall out' of interviews' column is calculated by multiplying the ROA distribution within the population by the target overall sample size. While the reduction of the overall survey sample size limits the ability to analyse at regional level, this expected distribution was felt to provide relatively robust base sizes for several regions (and survey data was weighted to be representative by region). The final column shows the actual (unweighted) distribution of interviews by ROA region, which was reasonably close to the expected distribution.

Population data is taken from the 2020 Inter-Department Business Register (IDBR) - the latest available business population statistics published by ONS at the time of sampling. Population figures are rounded to the nearest 100. The 'expected fall out of interviews' sums to 1,002 due to rounding.

Sample sources

As in 2019, Market Location was used as the principal sample source of the Scottish EPS 2021. The IDBR was not used as the sample source (nor any of the previous iterations of the Scotland-only survey) as the majority of records in the IDBR do not come with a telephone number.

Sample was ordered from Market Location at an average ratio of around 9:1 against target interviews required.

A total of 8,346 records were ordered from Market Location for fieldwork. This supplemented 299 records which were initially drawn for piloting purposes from the Scottish ESS 2020 survey (a sample of respondents that had given permission to be re-contacted). In total, 8,558 records were loaded for fieldwork. All sample records were postcode-validated to ensure that geographical regions had been correctly assigned. Checks were also undertaken in instances where duplicate telephone numbers existed within the sample. In certain sectors, such as Retail and Finance, it is common for different establishments to appear under the same centralised telephone number. Such establishments were marked up on the sample ‒ with the address of the sampled establishment displayed on-screen ‒ so that interviewers would be aware that the telephone number they were calling was a centralised switchboard and thus they would need to request to be transferred to a particular site.