The labour force survey is a sample survey conducted by interviewing households. Its main goal is to estimate the aggregates of labour supply: employed and unemployed.
The survey also collects information on individuals who do not belong to the labour force (inactive).
The main characteristics of the survey, i.e. methodological aspects, definitions of variables and indicators, are harmonized at European level, in accordance with international standards established by the ILO, and defined by specific Council and European Commission regulations.
Since 2004 the survey is continuous, that is, the information is collected on a continuous basis and referred to the 52 weeks that constitute the year, through uniform distribution of the sample over the weeks. The dissemination of information on the labor market takes is monthly, quarterly and on average for the year, with a differentiated level of detail. For example, monthly estimates are disseminated only at the national level, quarterly estimates at sub-national and regional level, while annual estimates go down to the provincial detail (which is the most detailed level).
The survey design also allows for the analysis of the labour market longitudinally, that is, the study of changes in employment status observed three and twelve months later among the same individuals. This particular feature of the survey design makes it possible to analyze transitions from one employment status to another, assessed precisely, at three and twelve months’ distance.
The reference population is composed of individuals between 15 and 89 years old from households whose tenant resides in the selected municipality. Therefore, from the reference population, permanent members of cohabitations (hospices, religious institutions, military) are excluded.
The survey unit is the de facto household, defined as a group of persons linked or not by ties of kinship or affection, habitually residing in the same dwelling and sharing income (contributing to and/or benefiting from income) and/or family expenses. All members of the de facto household (as of Sunday of the reference week) are therefore interviewed, including those who are temporarily absent at the time of the interview but have their usual residence in the dwelling.
If the absence continues for at least one year, it is no longer considered temporary, and the member is excluded from the de facto household.
Workers and students away from home, on the other hand, even if absent for more than one year, are considered included in the de facto household if they live in another dwelling exclusively for work or study reasons and contribute to or benefit significantly from the income of the other family members interviewed.
The temporarily absent members’ interview is done in proxy, asking the information from the family members present.
Those who live in the same household for economic or temporary reasons are not part of the de facto family, and therefore are not interviewed. For example domestic helpers and caregivers, baby-sitters, tenants, guests, etc.
People who have left the family permanently, even if they have not yet made the change of residence (e.g. the student who has left home permanently and lives elsewhere, supporting himself or herself, or the married son who has gone to live with his wife in another apartment, but has not yet made the change of residence), are also not included.
A household may consist of a single person (single-component household) or of several households sharing the same dwelling. In the second case, for example, the mother, father and son, daughter-in-law and grandchildren living together identify a single family and not two separate families.
In the re-interview, the de facto household is again considered, whereby all members of the de facto household at the time of the interview are interviewed, including any new members not already present at the previous interview.
The Labor Force survey is a sample survey, that is, conducted on only part of the population. Each household in the sample, extracted from the registry lists of the sample municipalities (LAC), is a theoretical representation of the set of households with the same characteristics.
Every year, about 250 thousand households are interviewed (62 thousand each quarter) for a total of about 600 thousand individuals. Households are randomly drawn from the registry lists of approximately 1,100 municipalities in Italy.
The sample is based on a sampling design with two stages and stratification of first-stage units: initially a sample is selected from all 8,100 Italian municipalities (First Stage Units, UPS) and then for these sample municipalities the households to be interviewed are selected by the LAC (Second Stage Units, USS).
The UPSs are stratified within each province based on the demographic size of the municipalities. This stratification leads to identifying two types of municipalities: self-representative (AR) municipalities, all of which are part of the sample; non-self-representative (NAR) municipalities, selected based on demographic size. The AR municipalities with the largest population size are involved in the survey every week; the other AR municipalities one week per month. Each of the NAR municipalities is involved in the survey one week per month according to a pattern of random association of weeks to the municipalities in the sample. This sample design remains fixed over time.
The sample has a rotated panel structure, meaning the same household is interviewed four times over a 15-month period. In each quarter, the Labor Force Survey sample consists of four sub-samples of equal numerosity, called rotating panels. The survey requires that on each survey occasion, a rotation group enter for the first time and conduct the first interview, another group be interviewed for the second time, and so on. Households in a rotation group will be interviewed for two consecutive quarters, will then observe a break during the two quarters that follow, and will be interviewed again in the additional two quarters, and then will permanently drop out of the sample.
As a result, 50% of households are re-interviewed at 3-month intervals and 50% at 12-month intervals, barring nonresponse. Overall, each household remains in the sample for a period of 15 months. The household rotation system in cross-sectional samples incorporates a longitudinal structure, but it is not a panel because the individual is not re-interviewed if he or she has changed residence or moved abroad between interviews. Thus, the longitudinal component represents the population residing in the same municipality both at the beginning and at the end of the period considered (“co-present” population).
The survey technique is mixed:
- CAPI (Computer Assisted Personal Interview) survey technique that has a face to face interviews conducted with the use of a computer;
- CATI (Computer Assisted Telephone Interview) survey technique that involves telephone interviews conducted with computer’s support.
The first interview is conducted with CAPI technique. All interviews following the first, for households that have a telephone, are administered with CATI technique. The interviews continue with the CAPI technique if the families do not have a telephone or for particular situations that highlight this requirement. On the other hand, the interviews are always carried out using the CAPI technique if the holder of the household form is a foreigner.
The three re-interviews have the objective of verifying the evolution of the families’ working conditions over time (i.e. between one interview and the next).
In the context of the health emergency and the government’s measures, ISTAT has taken actions to overcome the objective difficulties of conducting interviews in person. Therefore, even in the case of CAPI interviews, the interviewer contacts the households by telephone (or, if a telephone number is not available, by going to the home to retrieve the telephone number). The family is then usually interviewed by telephone, unless the family itself expresses a preference for a face-to-face interview, with previous consent and in full compliance with health regulations. For further information see the link https://www.istat.it/it/archivio/239854 on the Istat website.