Methodology 

The objectives of 2008 Social Survey: Households and Environment (ES08) are to investigate the habits, consumption patterns and attitudes of households and the population with respect to the environment, as well as household equipment and the use made of it in relation to different environmental aspects, in order to formulate environmental policies in relation to households (energy saving, reduction in energy consumption, selective collection of waste, etc.).

These statistics can be used to obtain comparable indicators with other autonomous communities and countries that have also conducted surveys like this.

2.1. Population

The population for this analysis is main family homes as a whole and the people that reside in them and are aged 16 years or over.

ES08 is aimed at the population that resides in main family homes, i.e. those that are for all or most of the year used as a regular or permanent home. It does not consider, therefore, so-called collective homes (hospitals, residences, barracks, etc.) or second or seasonal homes (summer homes, weekend homes, etc.). But it does include families that, forming an independent group, reside in such collective establishments (for example, the manager or porter of an institution).

In the particular case of families that use two homes on a regular basis (the mother, single or with children, in one, and the father in another, for reasons of work, studies, etc., or complete families that use two homes at the same time or in different seasons), the main home is considered to be the one that the family itself considers to be so. The other home is therefore considered secondary.

Finally, it is to be noted that with respect to the delimitation of what is considered a home for inclusion in this survey, the generic denomination of a family home includes homes with members that are not related as a family, as long as, as a group of humans, they comply with the requisites for being surveyed.

2.2. Territorial area

The whole Catalan territory.

2.3. Time period

The fieldwork was started in April and ended in July 2008.

The periods of reference varied depending on the blocks of questions in the questionnaire (last week, last month, last year).

The sampled unit is considered to be the main family home and the ultimate unit a person aged 16 years or over that lives in the home. The primary unit is the census section and the home is the second stage unit.

Stratified three-stage sampling was used on the primary units. The primary stage units were the census sections distributed by each of the territorial areas. Then the main family homes were selected, and in a third stage a person aged over 16 years was selected for each home, who answered a certain set of questions from the questionnaire.

The framework used for the selection of the first stage sampled units was a framework formed from the existing list of census sections in reference to January 2008. For second stage units, the list of family homes provided by this same framework was used, in each of the sections selected for the sample. To select the third stage units, while conducting the survey, the Kish table was used to make a random selection of one person aged 16 years or more residing in the home.

In Catalonia, strata were considered to be the crossover between an aggregation of territorial areas and different brackets for size of municipality:

• Territorial areas
  • Àmbit Metropolità
  • Comarques Gironines
  • Camp de Tarragona
  • Terres de l'Ebre
  • Àmbit de Ponent
  • Comarques Centrals
  • Alt Pirineu i Aran
• Size of municipality
  • Municipalities with 500,000 inhabitants or more
  • Capital municipality of a province with less than 500,000 inhabitants
  • Municipalities with more than 100,000 inhabitants
  • Municipalities with 50,000 to 100,000 inhabitants
  • Municipalities with 20,000 to 50,000 inhabitants
  • Municipalities with 10,000 to 20,000 inhabitants
  • Municipalities with less than 10,000 inhabitants

The affixation of the sample was not proportional in order to achieve estimations for the territorial area, the sample being set at 3,504 homes, with a relative error of 2.2%. In each census section, eight homes were selected.

In order to estimate the characteristics of the survey, ratio estimators were used, to which calibration techniques were applied, taking as auxiliary variables the information available on household and population variables correlated with the characteristics of the objectives of the survey.

This section explicitly details the main basic concepts of the survey.

Family home

Enclosure designed to be inhabited by one or several people not necessarily united through family relations and that do not constitute a collective home. A home is a structurally separated and independent enclosure that, due to the way it was constructed, reconstructed, transformed or adapted, is considered to be inhabited by people or, even if this were not the case, constitutes somebody's usual residence. An enclosure is considered separated if it is surrounded by walls, fences, hedges, etc., is covered by a roof and enables one person, or a group of people, to sleep and be protected from the elements and the environment. The enclosure is considered independent if it has direct access from the street or public, private, common or individually owned land, or by any type of staircase, corridor, walkway, etc., i.e. whenever the occupants of a home can get in and out of the same without having to pass through another enclosure occupied by other people.

Main family home

Family home that is used as a usual residence by one or more households. Family homes that are used seasonally, are uninhabited, etc., are not usual residences and therefore not main homes.

Member of a (main) family home

Person who usually resides in a family home. When at least one person resides in a family home, this home is considered a main family home and is therefore the object of study of this survey.

Usual residence

A person is considered to usually reside in a home if they use it as their home address and use it for most of their daily rest. If by any reason of work, studies, etc, a person has several homes, it is noted that only one may be considered the usual or main home. Similarly, it must be determined whether the people that due to whatever circumstance do not have a home that they could consider their usual residence, and that at the time of this survey are residing in a home in the sample, are considered members of the household or not.

Present/ Absent

A person is considered present if they sleep in the home at least for one night during the period of interviews (the period of interviews is the time spent in the section). A person that usually resides in the home is considered absent (temporary) if they do not sleep there for any night during the period of interviews.

Person of reference

Member of 18 years or more that resides in the home and that the ownership of the property is in their name (home owner) or that the lease or sublease of the property is in their name (rented home). If the home is provided free of charge, the person of reference is considered to be the person to whom the home has been leased. If two or more people share the same responsibility for the home, the person providing the largest amount of common income will be the person of reference.

Informant on the home

The ideal informant to be interviewed on first contact and who should provide general information about the home is the person of reference for that home. If this is not possible, it must be an adult person who is able "to speak in name" of the home.

In very exceptional cases, such as a home occupied by elderly or disabled people living alone, a person that is not a member of the home (for example, a child or acquaintance) that has perfect knowledge of the situation of the home.

Surveyable person

A person that is a member of the home and is 16 years old or more the month before the interview. One of these people will be selected to answer the individual module of the questionnaire.

Selected person

Person chosen from those that are surveyable in the home by means of the Kish table and who will be the person responsible for answering the individual module of the questionnaire.

Household

The people that reside in a home form one single household if they consume and/or share food or other goods paid for as part of a common budget. It is noted that the people who share this budget are both those who provide income and children, etc., that benefit from the same.

When the members of a home do not form a single household as defined, then they are considered to be two or more households. Each household can be formed by one person or a group.

The modules of the questionnaire related with the environment that were researched are:

• Water
• Energy
• Waste
• Equipment and use of the home in relation with the environment
• Problems with sound and bad smells
• Transport and mobility
• Lifestyles and consumption patterns

The characteristics that are the object of study can be classified into two types: of homes and of people.

5.1. Characteristics in relation to homes

In relation to water households are asked about their main source of drinking water, water-saving devices, and habits for reducing consumption. They are also asked about the application or not of any additional treatment of drinking water by the home prior to consuming it.

In the case of energy the use of electric energy is measured, as well as the availability of solar energy in the home and other sources of energy (piped gas, liquid gases, firewood, etc.). The availability of individual and collective heating is also examined, as well as different heating, air conditioning, thermal insulation and lighting systems. In relation to heating and air conditioning they are asked about the number of rooms, number of months of usage, availability of a thermostat and the temperature in different circumstances. They are asked if they have changed their heating system in the last twelve months and if so, their reasons for choosing this new heating system.

As for waste they are asked to inform about the proximity or not of specific containers for separating different types of waste, and their practices with regard to waste separation and how frequently they take this waste to the collection point.

As for the different equipment assets in the house, these are refrigerators, washing machines, tumble driers, dishwashers or cookers, and they are asked whether they have these, how old they are, and about their energy classification, frequency of use and availability of cheap-rate programmes, if relevant. In the case of small domestic appliances and audiovisual devices (microwave ovens, extractor fans, food processors, televisions, music systems) they are asked about frequency of use and availability. In the case of audiovisual systems they are asked if they use the stand by option.

Households are asked whether or not they suffered problems with noise in 2007. If they have suffered problems with noise or bad smells the aim is to find out their origin, frequency and the intensity to which they are suffered and the measures adopted.

Information is requested about the means of transport mainly used by the members of the home for working day journeys, the number of vehicles available, the characteristics of the vehicles in terms of type, availability of air conditioning, type of fuel used, how old they are, the kilometres covered in the past year and where they park.

Finally in relation to lifestyles and consumption patterns they are asked about consumer habits in relation to single-use products, recycled paper, returnable packaging and rechargeable batteries. They are asked about the factors they consider when purchasing a new product (price, brand, ratio between energy consumption and efficiency, ecological etiquette, local products, etc.).

5.2. Characteristics in relation to the selected person

The person selected from the household is asked for information in relation to their habits to reduce the consumption of water, what form of transport they use the most, the reason for using public or private transport, or going on foot or bicycle. If the person selected names public transport as their main means for getting around, they are asked about the days when they mainly use public transport.

As for the person's environmental awareness, measurements are made of their level of concern, whether they detected any environmental problems in their vicinity in 2007, if they have taken part in any activities related with the environment (environmental organisations, signing petitions, official denouncements, etc.) and whether or not they would be in favour of certain measures for protecting the environment.

The classification variables are the basic European social variables that have been proposed by Eurostat. For purposes of classification a difference is made between classification variables for households/homes and classification variables for people.

6.1. Classification variables for households

Households are classified while considering their own characteristics and those of the person of reference in the home.

Variables relative to the characteristics of the home and the household

• Territorial area
• Size of the municipality
• Size of the home (number of people that live in it)
• Type of household (single-person, couple, couple with children, single father or mother with children, household with other people)

  For these purposes, we understand a child to be one born or adopted by one of the couple, as long as their usual residence is the home and the child does not have their own partner or children living in the same home.

  Meanwhile, it must be considered that if there are several households in the home, this classification will be applied to the household of the person of reference in that home.

• Net monthly income of the household

  The sum of the regular income has been accounted for proceeding from all sources, received by all members of the household on average for the last 12 months, subtracting tax and social payments. The income of all members of the household must be considered, whether or not this income is partly or totally used to cover the household's expenses.

Variables relative to the characteristics of the person of reference

• Sex
• Age
• Nationality

  People with dual nationality, when one of these is Spanish, are included as Spaniards, and non-patriots as being From other countries.

• Relation with economic activity (employed, unemployed or inactive)
• Completed level of studies

  Highest level of studies completed by the person of reference

6.2. Classification variables of the person

The selected people are classified by the characteristics of the household they live in and their own socio-demographic and socio-economic characteristics.

Variables relative to the characteristics of the home and household

• Territorial area
• Size of the municipality
• Size of the home (number of people that live in it)
• Type of household (single-person, couple, couple with children, single father or mother with children, household with other people)

  For these purposes, we understand a child to be one born or adopted by one of the couple, as long as their usual residence is the home and the child does not have their own partner or children living in the same home.

  Meanwhile, it must be considered that if there are several households in the home, this classification will be applied to the household of the person of reference in that home.

• Net monthly income of the household

  The sum of the regular income has been accounted for proceeding from all sources, received by all members of the household on average for the last 12 months, subtracting tax and social payments. The income of all members of the household must be considered, whether or not this income is partly or totally used to cover the household's expenses.

Socio-demographic variables of the selected person

• Sex
• Age
• Nationality

  People with dual nationality, when one of these is Spanish, are included as Spaniards, and non-patriots as being From other countries.

• Country of birth
• Marital status
• Living with a partner
• Completed level of studies

Socio-economic variables of the selected person

• Relation with economic activity
• Type of job
• Occupation in accordance with the Catalan classification of occupations (CCO-94)
• Main activity of the company they work for in accordance with the Catalan classification of economic activities (CCAE-2009)

The method for collecting information is multi-channel, and combines collection by telephone interview, by face-to-face interviews, and also by the informant units filling in their own forms via Internet. The chosen homes first receive a letter from the manager of Idescat telling them they have been selected for this survey and requesting their collaboration with the supply of the information, as established in law 23/1998 for statistics in Catalonia. The field operation started on May 7 and ended on July 31, 2008.

In the information collection process the following incidences were reported in relation to collaboration:

Distribution of incidences in titular homes

	%
Unlocatable households	4.0
Inaccessible households	0.5
Empty households	2.5
Households used for other purposes	2.1
Surveyable households	90.8
Total	100.0

Once considered a surveyable household, the following incidences arose when attempting to conduct the survey:

Distribution of incidences in surveyable homes

	%
Refusals	19.2
Absences	13.9
Unable to answer	0.8
Collaborators	66.0
Titular	61.4
Reserves	38.6
Total	100.0

When starting the survey in homes, a member of the household was randomly selected using the Kish table, in order for that person to answer questions related with individual behaviours and attitudes.

Finally, as real sample was obtained of 3,425 valid surveys, obtained in 438 census sections, which represent 100% coverage, and a response rate of 97.7% of the theoretical sample of households.

The collection of information by means of the different methods was divided as follows:

Distribution of ES08 information collection methods

	Collaborating homes (%)	Collaborating people (%)
Face-to-face	82.5	82.7
Telephone	13.9	13.5
Internet	3.6	3.8
Total	100.0	100.0

On the understanding that ES08 contains questions relating to the household and the selected person, two different weighting factors were calculated. The first guarantees representation on the household level, and is used to produce the information to which these are related. The second factor guarantees representation on the level of the population aged 16 years or more, and is used for the statistical information in relation to people.

To correct for the lack of total response, and in order for the data elevated with the elevation factors for the households and people obtained to be adjusted to population data for May 15, 2008, the factor was calibrated using the CALMAR macro by SAS. For the elevation factors for households, margins were imposed for five-year and sex groups, and for the size of household, and for the elevation factors for people, five-year and sex groups were used, and for Spanish and foreign nationality groups were used.

The tables have been grouped into the following sections: water, energy, waste, equipment and use in the home, problems with sound and bad smells, lifestyles and consumption patterns, transport and mobility and environmental awareness.

To guarantee the statistical significance of the results being presented, a minimum sample guarantee was preserved for each of the tables. The cells that did not provide adequate conditions have been tagged as having under-significant data for calculation by using the symbol "..", taking into account the loss of information that eliminating it from the table would imply.

Definition of the theoretical framework and selection of variables

The conceptual objective of the Synthetic environmental indicator is to position households and individuals in accordance with their degree of awareness of environmental problems, taking into consideration both their group behaviour and their individual behaviour. The aim was to combine as a single indicator, information on household and individual habits that have an environmental impact, along with households' degrees of social awareness.

The different teams of experts in environmental issues that were consulted highlighted the following seven dimensions or core issues as being of special importance for the measurement of the environmental phenomenon:

1. Water saving
2. Energy saving
3. Disposal of common waste
4. Disposal of occasional waste
5. Consumer patterns
6. Transport and mobility
7. Environmental awareness

On the one hand, it is useful to consider the variables that deal with environmental impact due to the habits and behaviours of households, whether by one's own voluntary choice, or behaviours affected by their socioeconomic characteristics; we must not forget the impact that, for example, the family budget can have on the decisions adopted by households, regardless of their environmental awareness. On the other hand, we also include dimensions or core issues that consider the environmental awareness of individuals both in economic and social terms.

In order to identify the simple indicators or variables for each dimension, we made a selection from the questions in the ES08 questionnaire aimed at the totality of the chosen sample and which are listed below.

The resulting indicator was a compound hierarchic indicator, made up of the 76 simple indicators grouped into 7 dimensions, reflecting the multiple dimensions that the phenomenon is comprised of.

Water saving

The objective of the water saving dimension was not to directly measure the overall consumption of water by households but rather their saving habits and therefore the level of awareness of the effects of misuse of water. 9 simple indicators were selected as follows:

• Have a mixer or thermostatic tap
• Have water saving devices
• Have discharge limiting mechanisms
• Recycle water
• Fill the sink before washing dishes
• Fill up the dishwasher or washing machine before use
• Close the tap a little to limit the flow
• Turn off the tap when brushing teeth or soaping oneself
• Take a shower instead of a bath

Energy saving

In this dimension two types of simple indicators can be differentiated. On the one hand, we include indicators related with household habits, and on the other hand, indicators that evaluate the household equipment that, in most cases, is related with investments made by the family in order to reduce the energy impact of their homes. 23 simple indicators were selected:

• Have solar energy in the home
• Turn off the heating at night
• Levels of daytime temperature when the home's heating is on
• Levels of daytime temperature when the home's air conditioning is on
• Turn off the air conditioning at night
• Have windows with clothes line
• Have windows with Persian blinds
• Have windows with tainted glass or solar protectors
• Have windows with double glazing
• Have windows with thermal bridge insulation
• Have fluorescent tubes or lights
• Have low consumption light bulbs
• Rooms with fluorescent or low consumption light bulbs
• Energy classification of refrigerator
• Energy classification of washing machine
• Energy classification of tumble drier
• Energy classification of dishwasher
• Energy classification of cooker
• Use the washing machine's medium/economy load programme
• Use the independent tumble drier's medium/economy load programme
• Use the dishwasher's medium/economy load programme
• Programme the washing machine's temperature to less than 30 degrees
• Not use the standby option when turning off domestic appliances

Waste disposal

As for the waste disposal dimensions, we selected 4 simple indicators for common waste and 13 for occasional waste, which reflect household habits that influence the impact they have on the environment. The chosen variables for each of the sub-dimensions were as follows.

• Only separate organic waste
• Separate paper and cardboard
• Separate glass
• Separate packaging and plastic

• Dispose of vehicle tyres
• Dispose of motor oil
• Dispose of vehicle batteries
• Dispose of chemical products
• Dispose of medicines
• Dispose of small batteries
• Dispose of mobiles telephones
• Dispose of electronic devices
• Dispose of furniture and household items
• Dispose of rubble and other construction waste
• Dispose of cooking oils
• Dispose of fluorescent tubes
• Dispose of textiles and footwear

Consumer patterns

This dimension covers indicators that quantify the level of environmental awareness shown in consumer habits. But there are other factors that can affect consumer habits, other than environmental awareness, such as families' economic capacities and institutional support for consumptions (subsidies and grants), and environmentally attractive products. The selected indicators were:

• Use single use products
• Use recycled paper
• Use returnable packaging
• Use rechargeable batteries
• Consider energy consumption and efficiency
• Consider ecological etiquette or guarantee
• Consider local products and proximity

Transport and mobility

This dimension, which is also related with people's habits, contains important aspects for measuring the everyday impact that individuals have on the environment. This dimension is also notably influenced by factors that are external to households and individuals, such as institutional support for collective mobility, etc. The indicators are:

• People that travel on public transport, by foot or bicycle, or do not travel (%)
• People that travel in private transport (%)
• Type of vehicle 1
• Air conditioning in the vehicle 1
• Fuel used in the vehicle 1
• Most frequent means of travel
• Walking distances less than 2 kilometres

Environmental awareness

Environmental awareness, finally, seeks to measure the level of active implication shown by individuals in different environmental conservation activities. A total of 13 simple indicators were selected as follows:

• Show concern for the environment
• Collaborate with an environmental defence organisation
• Take part in environmental volunteering
• Sign petitions against environmentally harmful situations
• Protest against any environmentally harmful situations
• Personally denounce any environmental problem
• In favour of fining people that do not separate domestic waste
• In favour of restricting abusive use of water
• In favour of taxing the most contaminant fuels
• In favour of restricting the use of private transport
• In favour of establishing an ecological tourism tax
• In favour of installing renewable energy park
• In favour of paying more for the use of alternative energies

Data processing

Once the compound indicator had been designed, we continued by extracting the data from the variables contained in the ES08.

There was a need beforehand to make an imputation of the missing data from those Autonomous Communities where the survey had not been exploited. In these cases, the statistical institutes came to an agreement to use a common rule to facilitate the comparability and equity of the data. The method of imputation used was the result of seeking the arithmetic mean of the score for each dimension by only using the complete registers. Thus, the avoidance of any kind of bias was guaranteed.

With the data matrix complete, EUSTAT then proceeded with a multivariate analysis, with two aims:

• to determine the relevance of the simple indicators selected in the quantification of the degree of environmental awareness
• to identify, in turn, those dimensions of the greatest importance for environmental awareness

An analysis of correlations was made for the whole set of selected simple indicators. The main conclusions drawn, and which were reproduced in all of the analysed Communities, can be summarised as follows:

• The indicators for the "Common waste" dimension presented a high correlation, of almost 0.8; therefore, there is a major positive correlation between the recycling of paper and the recycling of glass and plastic packaging.
• The indicators "Dispose of tyres of vehicles", "Dispose of motor oil" and "Dispose of vehicle batteries", belonging to the dimension "Occasional waste" also presented a high correlation, greater than 0.7. In this case, it seems that the main reason for the correlation is that in the three cases the recycling of the identified products (all originating from vehicles) requires prior knowledge before extraction/substitution/renewal.

As for the other variables, no significant correlation was found. The information obtained through the analysis of correlation is of vital importance for the assignation of weights to each of the simple and compound indicators associated to each of the dimensions that make up the general compound indicator that is described later.

Once the matrix of variable correlations had been made, a Factorial Analysis was performed. Details of the results obtained were outside of the aims of this document, and we should simply state that, due to the data matrix used, no factors were obtained that explain the variability of the data in a significant fashion.

Given the results obtained, the multidimensionality of the concept of environmental awareness being analysed is patently clear. The degree of awareness of a household or individual is determined by a broad set of behaviours, habits, attitudes and even convictions. All of these, moreover, can be applied to different areas and situations, such as water consumption, use of energy, use of transport, etc. No significant correlations were found between the different environmental behaviours and neither was a small number of factors detected that could enable, with any guarantee in terms of the explained variance, a reduction of the dimension of the phenomenon. This has lent statistical support to the high number of dimensions and simple indicators selected for the compound indicator.

Having analysed the data matrix and before proceeding with the aggregation of simple indicators, there was a need to standardise the data, on the understanding that the simple indicators presented different units of measurement. The different groups of experts on environmental issues that were consulted recommended the penalisation of certain answers associated to behaviours, attitudes and habits that are contrary to environmental conservation. This made it possible to introduce better matrixes (for example, to neutralise or compensate for some answers with others) and enrich the final result, because the levels of environmental awareness are measured with a higher level of demand.

The standardisation criteria proposed by the experts are detailed in the following table:

It can be observed that, given the standardisation of all of the simple indicators into values between −1 and 1, when there is penalisation, and between 0 and 1 for indicators without penalisation, the minimum possible aggregate score for a household is −47 points, and the maximum is 75 points.

Although this standardisation was correct, we later opted to transform the variables using the lineal function "y = 5x + 5", in such a way that the range of possible values was from 0 to 10 points. Thus, the interpretation of the aggregate scores was more immediate and intuitive.

Construction of the synthetic indicator

With the structure of the Environmental Indicator defined and criteria for the standardisation and transformation of the data adopted, the following stage was the aggregation of the simple indicators into compound or synthetic indicators, associated to the dimensions. In the same way, the compound or synthetic indicators of the seven dimensions were aggregated to form the overall synthetic indicator. The aggregation was performed using a weight vector in each of the two aggregation phases (from simple indicator to dimension, and from dimension to overall indicator).

Each team of experts consulted by the different statistical institutes, once the structure of the indicator had been defined, proposed one or several weight vectors (the INE, representing numerous Autonomous Communities, contributed the greatest number of weight vectors) which considered at all times the results derived from the previously made multivariate analysis. In the case of Idescat and for the data corresponding to Catalonia, the experts that defined the weight vector were a team of specialists from the Department for the Environment and Housing.

Once the vectors had all been obtained, the Work Group's task was to use the arithmetic mean to make it possible to:

• Represent all of the Communities in the best possible way, including both singularities and aspects common to all of them.
• Full comparability of all of the results obtained

The weight vector that was finally obtained is that which corresponds to the following table:

The aggregation for each family was performed in two phases. In the first phase, the values of the simple indicators were lineally aggregated to obtain a value for each compound synthetic indicator associated to each dimension. In the second phase, the values obtained for each of the dimensions were lineally aggregated, using the weights (third column) in order to obtain the value of the Environmental Indicator.

From here, the score was obtained (always positive but less than or equal to 10) for each occupied home that, as a whole, constitutes the evaluation that for each group of variables are obtained by the whole set of Catalan households with respect to their environmental behaviour (Table 1).

Table 2 presents the percentage households, grouped according to three levels of environmental awareness, for each of the dimensions studied before:

• Low level: percentage households with a score from 0 to <4 (0, <4)
• Medium level: percentage households with a score from 4 to <7 ( 4, <7)
• High level: percentage households with a score from 7 to 10 inclusive (7, 10)