### Methodology

The Annual Population Survey (APS) is a continuous household survey. Most people are interviewed in person first, and later by telephone. The sample is formed partly from waves 1 and 5 of the Labour Force Survey (in which selected addresses are contacted every 3 months) and partly from boost cases that are in the sample for 4 waves, spread one year apart.

Participants are randomly selected from the Royal Mail Postcode address File (PAF). The NHS communal accommodation list is also used and (in the case of remote parts of Scotland) telephone directories. All eligible individuals found at the selected address may be interviewed. Individuals are included in the dataset for this analysis if they respond themselves or if a family member responds on their behalf. The complex survey design has been taken into account when calculating confidence intervals.

Weighting:

The achieved sample of approximately 275,000 undergoes weighting which is structured at local authority level and uses age and sex dimensions.

Weighting is used to adjust the results of a survey to make them representative of the population and improve their accuracy For example, a survey which contains 25% females and 75% males will not accurately reflect the views of the general population, which we know is around 50% male and 50% female.

Statisticians rebalance or ‘weight’ the survey results to more accurately represent the general population. This helps to make them more reliable.

Survey weights are usually applied to make sure the survey sample has broadly the same gender, age, ethnic and geographic makeup as the general population.

The Office for National Statistics population estimates and projections are used as the basis for this weighting process.

Confidence intervals:

Confidence intervals for each ethnic group are available if you download the data.

Based on the APS, it is estimated that 3.9% of White individuals who were economically active were unemployed in 2017.

The data from the APS is based on a sample of the population in England, Wales and Scotland, rather than the whole population. The estimate obtained from this sample is a reliable estimate of the percentage of individuals unemployed, but it’s impossible to be 100% certain of the true percentage for the whole population.

It’s 95% certain, however, that somewhere between 3% (lower bound of the confidence interval) and 4.8% (upper bound of the confidence interval) of White individuals who were economically active were unemployed in 2017. In statistical terms, this is a 95% confidence interval. This means that if 100 random samples were taken, then 95 times out of 100 the estimate would fall between the lower and upper bounds of the confidence interval. But 5 times out of 100 it would fall outside this range.

The smaller the survey sample, the more uncertain the estimate and the wider the confidence interval. For example, the sample has less data for individuals from the Black ethnic group than from the White ethnic group, so we can be less certain about the estimate for the smaller group. This greater uncertainty is expressed by a wider confidence interval, of between 3.8% and 14.4% for the Black ethnic group compared with 3% and 4.8% for the White ethnic group in 2017.

### Suppression rules and disclosure control

In data covering all ethnic groups together, estimates based on sample sizes of less than 30 have been suppressed. For data broken down by ethnic groups, estimates based on sample sizes under 100 have been suppressed.

‘Suppression’ means these figures have not been included in the data, to protect confidentiality and because the numbers involved are too small to draw any reliable conclusions.

### Rounding

Percentages are rounded to whole numbers in charts and tables. Download the data to see the percentages rounded to 1 decimal place.

Quality and methodology information