Secondary Consequences of Consumption Decisions
This section provides an overview of the secondary consequences that purchase, use and end-of-life of a product can induce outside the actual product system itself. These consequences go beyond functional relationships with other products, i.e. beyond part-system and system-system relationships that are part of regular product LCA, and which are described in the ILCD Handbook, Chap. 7.2.2.
The following consumption-induced secondary consequences and aspects that modify them can be differentiated (compiled from Becker 1976; Eyerer and Wolf 2000; Hofstetter et al. 2006; Weidema 2008; Girod et al. 2010, with additions):
• Changes in the available household resources income, time, and space, as well as further constraints to consumption, particularly food calories uptake capacity, drink intake capacity, skills and information availability, and access to products
• Use of the freed household resources (or restrictions in case of reduced household resources)
• Cross category effects
• Mental secondary consequences
The above listed secondary consequences cause additional or reduced consumption.
Beyond these, other secondary consequences occur on local, regional, national
or international scales that are not addressed in this chapter.
In three additional sub-sections the authors look briefly into higher order consequences due to economic transactions, present a new measure of the environmental life cycle performance of products from consumption perspective and reflect on possible harm due to needs over-fulfilment.
Changes in Available Household Resources and Consumption Constraints
The following household resources have been considered for studies on sustainable consumption (compiled from Becker 1976; Eyerer and Wolf 2000; Hofstetter et al. 2006) Weidema 2008; Girod et al. 2010, with own additions and examples):
• Available income
• Space (volume, area)
Moreover the following elements, which are better understood as constraints to consumption, are to be considered (Hofstetter et al. 2006):
• Food calories uptake capability
• Drink intake capability
• Skills and information
• Access to products and technologies
2.2.1 Available Income
Changes in available income – always a decrease – occur with any purchase decision, while decisions during use (e.g. more efficient use, shared use) and when selling a used product, the available income can increase compared to the default case. This additionally available income allows for additional consumption.
While each purchased product initially reduces the consumer's time budget, due to the purchase process, some products have relative time saving advantages compared to the average product and others enable to actually increase the available time budget of the consumer on a net basis: car navigation systems or apps with traffic avoidance, integrated washing and drying machines, crease-free shirts, faster internet connection, etc. all save time. This time is made available for additional consumption but also for other activities (e.g. economic activity to generate extra income, or resting, i.e. (near) non-consumption).
Space (volume and area) to store or use goods is a physical limitation. Examples are the living area that limits the amount of furniture that can sensibly be put, storage space to keep clothes, parking space in cities that may relevantly limit the option to have a second car, the consumer's skin surface that can only so many times per day be treated with crèmes or lotions, or storage space on storage media in a computer. However, many products offer the possibility to increase or better use the available space, either as a secondary product property (e.g. a Smart car may be an option as second car even in city centres with severe parking space limits), or as a primary property (e.g. vacuum bags for storing bed clothes, shelves, external hard disks, etc.). While each Euro can only be spent once, and the number of things one can do at the same time is limited, spatial limitations are arguably less absolute, while at
least an asymptotic saturation of the available space can be observed in reality.
2.2.4 Food Calories, Drink Intake
The amount of calories that we can digest is also limited. The market growth potential of the food industry therefore lies in selling further processed food with higher value added as well as in convenience food in smaller packages at a higher per calorie price. Diet food is another key option to sell more food without surpassing the individual's overall calorie uptake limit. Eating more calories is formally one way to expand this limit, although again not limitless and with possibly harmful consequences (see Sect. 2.8). Still, certain limits exist in the volume that people can or at least want to eat.
Similar limitations exist for drinks, while our body is better able to put through
water than carbohydrates, proteins, and fat.
2.2.5 Skills and Information
Skills and available information can be an important limitation to consumption, but we argue that they are of a different nature than the previously listed ones: with the purchase of a good or service the consumer is not negatively affecting his or her skills and available information, in contrast to the situation for money, time, and space. If anything, they would be increased. Skills and available information are however a constraint to consumption of those goods that require a higher level of skills or information.
Next to absolute limitations of personal aptitude, the necessary money and time needed to acquire the specific skills can be a relevant obstacle to consumption. Examples are leisure activities such as operating a small sailing boat, constructing the own furniture, or playing the piano. However, the idea of a knowledge based society and the growing offers of online courses for virtually everything and instructions and courses offered by do-it-yourself markets are however eroding the limitation of information.
At the same time, the process of learning the required skill may be a key part of the activity and the success to have mastered the skill can be an important contribution to the individual's needs fulfilment. Legend are however the households that have a piano with nobody in the family being able to play it.
2.2.6 Access to Products
Similarly, limitations to access products are an obstacle, but they are not affected by the consumption of individual other products, while the wider consumption pattern can strongly affect them, particularly if consumption thresholds need to be surpassed to make them economically viable: A good example of such limitations is the availability of car sharing outside the larger cities' centre. Such access restrictions are partly a matter of relative demand limitations – while in a hen-and-egg situation, where limited demand means that the necessary threshold is not achieved to make the product available – but partly also absolute, where a frequent public transport service would not be economically or even environmentally sensible for very remote places with virtually no population.
2.2.7 Interchange Ability of Household Resources
While these household resources and other constraints have their own budget, we note here that compensation across some of these is possible to a large extent, firstly time and money: a consumer can free additional time by hiring another person for cleaning or other household work, or by buying time-saving equipment. Similarly, space and money: the available space can be extended by using some of the available household income for renting a larger flat or extra storage. And we have given already the example of using time (and potentially money) to acquire new skills or information. Finally, investment of time can mean to take up extra economic activities to increase the available household income.
However, where money transactions are involved – such as in the example of contracting a cleaning service – the service provider received additional household income, hence can consume more. We will come back to this characteristic of money being conserved, and what this implies for sustainable consumption.
-  Income is the sum of all the wages, salaries, profits, interests payments, rents and other forms of earnings received… in a given period of time. (Case et al. 2014)