Methodology

The data from the Population Census concerning the location of economic activity of the employed population on the location of the students place of study allows for knowing the commuting for the population by comparing the place of work/study with the place of residence of the workers and students. The Population Census also examines commuting characteristics like means of transport used, number of trips and their duration, while connecting these variables to demographic and economic characteristics.

The first data on commuting dates back to 1986 and corresponds to the treatment of that year's Municipal Population Register. Later, data on commuting was published on the basis of the Population Census of 1991, the Population Statistics of 1996 and the Population Censuses of 2001 and 2011.

2. 2011 Population Census

The census model used by the INE to elaborate the Spanish Population and Housing Census 2011 consists of an operation that combines the use of administrative records with the sample-based survey and the count of buildings. The availability of the Population Register as a consolidated population record has made it possible to produce a census of such a nature. So, unlike previous censuses, in which the whole resident population had to answer the census questionnaire, the 2011 commuting data was obtained from a survey that in Catalonia was addressed at 622,070 respondents, a figure representing 8.3% of the population.

3. Methodology

The reference population for the study of commuting to work reasons is the resident employed population (REP), which is comprised of all employed residents, including both those working outside and within the resident area.

The located places of work (LPW) are people that work in the location where they reside and those that commute from outside to work there but live in another area. The LPW are undercounted in the census data for two reasons: on the one hand, there are people that commute to work in several municipalties, which is why they cannot be assigned an LPW. No information is available on the commuting to work and study reasons of people residing in other autonomous communities and that travel to Catalonia to work or study, so it is not possible to identify the total number of jobs or study locations in Catalonia.

The same analysis applies to both the resident students (RS) and located places of study (LPS).

The unit of analysis in the statistics of commuting are those persons who are residents of Catalonia that are working and residents of Catalonia that are studying. In the 2001 and 2011, when a person was both studying and working they only had to answer questions about commuting related to work. This criteria is not maintained in earlier years. So, in Population Statistics of 1996, the 1991 Population Census and the 1986 Municipal Population Register, the same person prioritised which of the two activities (work or study) was the main one.

With respect to age, all editions of the statistics include all people that work or study, with the exception of 2001, which only included information on the population aged 16 years and over.

In the 2001 and el 2011 censuses, part of the working and student population did not have to answer the specific questions on commuting in the census questionnaire and were therefore excluded from the analysis. These were people that:

• Do not travel because they work or study at home.
• Work or study in different municipalities, about which only the city of residence is known, but not the work or study city
• Have a second residence from which they travel to work or study, about which only the municipality of residence, work or study are known, but the municipality of the second home from which they commute is not available.

Questions about the mean of transport have differed across the different editions. In the 2001 and 2011 censuses the data collection categories were modified and it was possible to answer with up to two possibilities in reference to longer journeys. The 1991 Population Census and the 1996 Population Statistics asked about the most frequent modes of transportation for the longest journey, and the 1986 Municipal Population Register only asked about the most frequent mean of transport.

The 2001 and 2011 censuses asked about the number of journeys per day, which corresponded to the outward journey and the return journey, as well as the journey time from home to the place of work or study. These two variables were absent in the previous editions.

4. Definitions and variables

The following categories are defined:

Employed residents that work inside area

Persons that work in the same geographic area in which they reside.

Employed residents that work out-of-area

Resident persons in the selected geographic area that work in a different area.

Employed non-residents that work inside area

Persons that work in the selected geographic area but reside outside of this area.

Resident employed population (REP)

Resident employed population = Employed residents that work inside area + Employed residents that work out-of-area + Employed residents that commute to several municipalities.

Located places of work (LPW)

Employed residents that work inside area + Employed non-residents that work inside area.

Residents that study inside area

Resident persons that study in the same geographic area in which they reside.

Residents that study out-of-area

Resident persons in the selected geographic area that study in a different area.

Non-residents that study inside area

Persons that study in the selected geographic area but reside out of this area.

Resident student population (RSP)

Resident student population = Residents that study inside area + Residents that study out-of-area + Students that commute to several municipalities.

Located places of study (LPS)

Residents that study inside area + Persons that study out-of-area.

Difference

The difference between the number of located places of work/study and the resident employed/student population by geographic area.

Mean of transport

In the 1986, 1991 and 1996 editions, the mean of transport used for journeys were grouped into three categories:

• Collective: Bus, train, metro, company bus, etc.
• Private: Car, motorbike or bicycle.
• Others: On foot, does not travel and a small percentage of blank responses.

2001 and 2011 Population Census:

• In car or van as driver.
• In car or van as passenger.
• In bus, coach or minibus.
• In metro.
• On motorbike.
• Walking.
• On train.
• On bicycle.
• Other modes.

Mean of transport

Tables grouping the mean of transport categories:

• Private: Car, van or motorcycle as driver, car or van as passenger or motorbike, plus combinations of these categories between them or with non-motorised transport (walking and bicycle).
• Public: Bus, coach, microbus or metro or train, plus combinations of these mean of transport between them, with private transport (car o bike) and with non-motorised transport (walking and bicycle).
• Non-motorised: Walking or bicycle and their combination.
• Non-commuting: Works or studies at home.
• Not applicable: Works or studies in several municipalities, has a second residence at the place of work or study or did not answer this question.

Number of journeys per day

Corresponds to a roundtrip. The tabulation categories are:

• Does not travel: Works or studies at home.
• One a day: One roundtrip.
• Two or more journeys: More than one roundtrip per day.
• Not applicable: Works or studies in several municipalities, has a second residence at the place of work or study or did not answer this question.

Travel time

The travel time to work or study was asked about for the first time in the 2001 Census. The categories for travel time were:

• More than 10 minutes.
• From 10 minutes to 20 minutes.
• From 21 minutes to 30 minutes.
• From 31 minutes to 45 minutes.
• From 46 minutes to one hour.
• From one hour to an hour and a half.
• More than an hour and a half.

Activity types

Commuting to work is presented by branches of economic type. The classification of activities has changed over the years. The location of employment by activity branches used the CCAE-74 in the 1986 and 1991 editions and the CCAE-93 in the 1991, 1996 and 2001 editions. The 2001 Population Census used, for the first time, the CCAE-2009 classification, a version that grouped activities into 10 categories.

Profession

Profession refers to the class or type of work done, regardless of the activity of the workplace. The employment classifications used are the National Classification of Occupations 79 (CNO-79), to one digit, for 1986 and 1991; the Catalan Classification of Occupations 94 (CCO-94) for 1991, 1996 and 2001, and the Catalan Classification of Occupations 2011 (CCO-11) for 2011.

Rate of municipal or county self-containment

The municipal or county self-containment refers to the percentage of people working in the same municipality or county in which they reside, of the whole of the resident population of that area. This indicator can be calculated both for commuting for work reasons or for studying.

Rate of municipal or county self-sufficiency

The municipal or county self-sufficiency refers to the percentage of people working in the same municipality or county in which they reside, of the whole of the local work places of that area. This indicator can be calculated both for commuting for work reasons or for studying.

5. Dissemination

The results of the statistics on commuting are published by municipalities, counties, areas of the Territorial Plan, provinces and Catalonia. In the 2011 Population Census, the commuting for purposes of work and study was analysed for municipalities greater than 200,000 inhabitants. To do so, the post codes of the place of residence of the working population and their workplaces were analysed, and also the post codes of the students’ place of residence and place of study. This information has been published in csv format.

The methodology of the 2001 Population Census, which includes survey data, makes specifications regarding when the results are to be published. The information cannot be offered for all territories, as was the case in previous treatments, and there was a need to establish minimum municipal population thresholds beyond which the values are not published because the reliability of the information cannot be guaranteed. In this regard, no data is provided corresponding to a sample frequency of fewer than 10 cases. The boxes calculated with less than ten sample units appear with the ".." symbol.

Finally, the 2011 Population Census results have been rounded and shown without decimals. For this reason, some totals do not add up to the disaggregated data.