Energy Demand by Households and Household Characteristics
In the present study private households' energy expenditures according to National Accounts and according to the consumer survey were analysed in order to enhance the understanding of their energy demand. Statistics Austria's consumer survey represents an important data base regarding the consumption structures of Austrian households. In addition to illustrating the development of consumption expenditures (according to National Accounts) over time the consumer survey allows for an analysis of more profound interrelations between socio-economic characteristics and energy consumption. The interpretation of results requires, however, taking into account information from various other databases as well. This approach was chosen for the present analysis.
As was also shown by other national and international studies transport in general and private households' mobility demand in particular are a main area of concern in climate change policy. This is also confirmed by various indicators from the present analysis regarding the development of transport volumes and emissions from passenger transport.
Residential energy use (heating) is to a large extent determined by climatic factors. The increase of total and per capita electricity demand is another remarkable aspect in this context. The electricity use for selected household appliances is considerably rising mainly due to an increase in the number of households. At the aggregated level a certain rebound effect can be observed, i.e. increases in efficiency of categories of appliances are offset by higher demand (see Figure 3.2 in the final report). Changes in lifestyles, like the trend towards single households, increases in living space per capita and a change in household equipment determine residential energy demand while in transport the driving factors are an increase in individual motorised traffic (in terms of the number of cars and mileage) and the trend towards more powerful cars.
In order to analyse the structure and development of energy expenditures (according to National Accounts) changes in demand were decomposed into a quantity and a price effect. Thus, for example, the substitution of liquid fossil fuels by natural gas could be demonstrated. Especially for liquid fossil fuels the quantity and price effects point into opposite directions. Consumption expenditures for public transport in turn are characterised by a negative quantity effect (see Figures 4.3 and 4.5 in the final report).
Using the data from the consumer survey energy expenditures of all households were analysed dependent on various relevant characteristics (location, legal status of the dwelling, etc.) in a first step. In the following also household size and composition were controlled for in order to calculate standardised expenditures and thus reducing the variance of expenditures between households with differing characteristics.
Transport as well as energy expenditures for dwelling are strongly determined by the households' location. For energy expenditures for heating also the availability of net based energy sources (e.g. district heating) is an important factor. The legal status of a dwelling affects the possibilities for energy saving.
Finally, differences in preferences were determined with econometric methods using data from the consumer survey and it was analysed how households with different characteristics would behave given an equal level of income. In this analysis, disparities in expenditure shares between observed and hypothetical consumption cannot be attributed to differences in preferences or income but are caused by other determining factors (e.g. technologies used, thermal quality of the building).
According to the theory of Engel curves the share of a household's energy expenditures declines when income rises (satiation). If differences in wealth are eliminated the contrary is observed. Climatic factors, technologies used or the thermal quality of buildings plays a larger role in determining residential energy expenditures than do differences in income. When transport is analysed a close relationship between expenditures and land use planning becomes evident, i.e. expenditures are widely determined by car ownership.
Angela Köppl, Michael Wüger
Österreichischen Instituts für Wirtschaftsforschung (WIFO)