[1]
Where is the direct emissions related to household consumption; n refers to the fuel type used by households, such as electricity and natural gas; Fi is the annual energy consumption by fuel; Ci is the CO2 coefficient by fuel type. Input–output analysis is widely used to estimate indirect emissions related to household consumption. IOA is based on the Leontief quantity model[[] W.Leontief:1970. Review of Economics and Statistics 52（1970）, 262–271 ], the indirect emission of per unit final demand obtained through so-called Leontief inverse. The equation can be represented as: e=c(I-A)-1.Where e is a row vector of indirect emission coefficients. c is a row vector of direct emission coefficients. (I-A)-1 is the Leontief inverse matrix. The total indirect CO2 emission can be calculated through the formula:
DOI: 10.47915/jese.2016.v58i04.003
Google Scholar
[2]
Where is the direct emissions related to household consumption; m refers to the number of sectors the households consumed; ej is the CO2 coefficient of the sector j;Xj is the per capita expenditure of the household in the sector j;P is the population. Domestic emissions and imported emissions.At present, no country is isolated from other countries. International trade contacts the countries all over the world as a whole. Global trade means a country's carbon footprint is international. Here, imported emissions refer to CO2 emissions embodied in import final goods and services, which produced abroad and used by domestic consumers. Domestic emissions conclude two parts. The first one is the emissions embodied in goods and services produced and consumed all domestically. The second one is the direct emissions of the imported final goods and services consumed by households domestically. The formula for estimating the imported CO2 emissions related to household consumption is presented below:
Google Scholar
[3]
Where is the imported emissions related to household consumption; m refers to the number of sectors the households consumed; ej-im is the CO2 coefficient of imported goods and services in the sector j;Xj-im is the per capita expenditure of the household on imported goods and services in the sector j;P is the population. The accurate esimation of ej-im needs a global input–output table to get the individual emission coefficients of different importers. However, the global input–output table is much difficult to get and update. So the EAI ("emissions avoided by imported") assumption is widely adopted to estimate the emissions embodied in imports. The EAI assumption means that the emission coefficients of imported goods were the same as those manufacted domestically. In fact it measures the emissions of the imports if they are produced domestically. The domestic emissions are equal to the total emissions related to household consumption minus the imported emissions. The formula for estimating the domestic CO2 emissions related to household consumption is . At present, the Kyoto Protocol adopts "producer responsibility" to estimate CO2 emissions of one country. It means a country should be responsible for emissions due to the production of goods and services. To a certain extent, we can reduce the emissions by import high-emissions products. Autonomous emissions and induced emissions.Along with the concept of autonomous consumption, autonomous emissions refer to CO2 emissions embodied in autonomous consumptive goods and services which to satisfy households basic needs. And the induced emissions mean CO2 emissions embodied in induced consumptive goods and services which increase along with the income of households. The key to quantify the autonomous emissions is to estimate the autonomous consumption. It can be obtained through the basic formula :
Google Scholar
[4]
Where consumet and consumeau are the total and autonomous consumption respectively; β is the marginal propensity to consume. Then we can estimate the autonomous emissions as follows:
Google Scholar
[5]
Consistent with the previous definition, means the autonomous emissions ; is the per capita expenditure of the household on autonomous goods and services in the sector j . The implicit assumption is that the households have the same proprtions of autonomous goods and services. The induced emissions are equal to the difference between the total emissions and the autonomous emissions. Summary Different from the CO2 emissions related to the productive process, the emissions related to household consumption are determined by countless various households. Though the daily emission of a single household is limited, even negligible, the accumulated number is very enormous. Besides the economic factors, the psychological factors play an imortant role in a consumer's decision making. Of course, the psychological factors affect the emissions deeply. Changing the lifestyle can reduce the emissions, to a certain extent, at the cost of reducing the comfort of the household members. Extending the household metabolism model to open economy, the emissions related to household consumption can be divided into three categories: direct and indirect emissions; domestic and imported emissions; autonomous and induced emissions. According to the above results, we derived main policy implications as follows. Changing lifestyle is vital to reduce CO2 emissions related to household consumption. The government should take a variety of ways to the public's view of life. What we need is a healthy life, not just a comfortable life. The use of energy-saving equipments is important to reduce CO2 emissions related to household consumption as well. Accounting to the high prices, the government should give some subsidies to low-income households, helping them to use the energy-saving equipments. Based on the "producer responsibility" , it is a reasonable way to reduce the emissions by import high-emissions products. It is important to stress that this paper is only a preliminary study. Better understanding of CO2 emissions related to household consumption needs much further research in the future. Acknowledgements This work was financially supported by Natural Science Foundation of China (70873028). References
Google Scholar
