1 Urbanization and lifestyle trends in China: Implications for the carbon emissions problem Nicholas Apergis, Northumbria University, U.K., [email protected] Jun Li, Curtin University, Australia, [email protected] 1 Urbanization and lifestyle trends in China: Implications for the carbon emissions problem ABSTRACT Demographic changes have significant impacts on a country’s long term growth trajectory through the savings, consumption and labour market channels. Population changes, including ageing, migration and urbanization may affect significantly the growth prospects for fastgrowing developing countries, like China. Rural population migrates to cities and will need more energy services and will produce more CO 2 emissions since urban lifestyle turns out to be generally more energy-intensive. Population and household structures also keep changing across the majority of Chinese cities. Migration and urbanization together are likely to drive China’s energy consumption, CO2 emissions and air pollution upwards if the current trend is to continue. It is, thus, necessary for China to draw useful lessons from experiences in advanced economies in terms of reconciling population development and environment issues. This study aims to analyse, for the first time, the challenge of environmental sustainability, resulting jointly from population and lifestyle changes in China over the period 1978-2012. 3 The empirical analysis, through cointegration and instrumental variables methodologies, generates empirical findings documenting that urbanisation, population changes and consumption behavioural changes contribute significantly to increased carbon emissions. The results seem to be highly significant for policy makers who need to adopt new policies to mitigate the environmental problem China has to cope with over the next years. Keywords: Carbon dioxides; Urbanization; Life-style; China JEL Classifications: Q43; R23; D11 1. Introduction Over the past years, in the development process of the majority of developed countries, it has been documented that industry accounts for the largest proportion of carbon emissions. However, recently, a number of studies highlight that the contribution of residential energy consumption to carbon emissions has exceeded that of industrial sectors. Therefore, new research has focused on exploring the effect of population growth, the associated residential consumption and the adopted new lifestyles of the population on carbon emissions (Bin and Dowlatabadi, 2005; Druckman and Jackson, 2009). Moreover, the study of contemporary urbanization and its impact on the environment is increasingly central to a wide variety of scientific disciplines. Increasing attention is due to the rapid growth of cities in many parts of the world, the growing awareness of the importance of society-wide social, biophysical, and infrastructural changes that accompany urbanization, and how these dramatic shifts influence trends across a range of environmental issues at multiple geospatial and temporal scales (Douglas, 2013). Of particular concern is the role of cities and the urbanization process in climate change and specifically the carbon cycle (Seto and Reenberg, 2014). There are ongoing debates about either whether urbanization is fundamentally detrimental to environmental quality (Srinivas, 2000; Brown, 2001) or, with appropriate governance, incentives, and cultural capacities, urbanization can be a potential path toward low carbon societies (Owen, 2009; Glaeser, 2011)]. 3 The literature has recently started to closely monitoring urbanization levels, given that these levels are highly relevant to residential consumption as well as to consumption structures. Urbanization generally affects carbon emissions through three mechanisms: i) the use of energy in production is concentrated primarily in cities; as a result, residential consumption increases in line with urbanization. The total outcome leads to higher energy demand, resulting in carbon emission increases, ii) the requirements for infrastructure and dwelling houses grow, leading to higher levels of the demand for building materials, which are important sources of carbon emissions, and iii) urbanization involves the conversion of grasslands and woodlands, with such land-use changes increasing carbon emissions. The goal of this paper is to analyse the challenge of environmental sustainability resulting from population changes in the Chinese economy spanning the period 1978-2012. In particular, in this study we investigate, for the first time in the literature, the joint effect from both lifestyle characteristics and urbanization levels in China on carbon emissions. By doing so, we are expecting to get more complete and accurate information reflecting the impact of those drivers on carbon emissions. To this empirical end, we make use of both cointegration and Instrumental Variables (IV) methodologies. The empirical findings are expected to provide substantial guidelines for policy makers on how to mitigate carbon emissions, by explicitly intervening and targeting urbanization and lifestyle, without, however, reducing the households’ standard of living. China’s demography has been evolving rapidly. In Europe, population ageing started early but evolved slowly, it took 50-100 years to double the population aged 65 and over, or from 7% to 14% of the total population, whereas it took only 25 years to complete this process in China. Ageing population has long term implications for lifestyle changes and consumption behavioural shifts of the society. Today, urbanization in China is just over 50%. Rural population migrated to cities will need more financial support from the social security system, while it will produce more CO2 emissions, provided that urban lifestyle turns out to be more energy-intensive. Migration, urbanization and family miniaturizing together are likely to drive China’s energy consumption, CO 2 emissions and air pollution upwards if no control is put in place. More specifically, since the 1990s, the total living expenditures in both urban and rural areas have doubled. Across the Chinese territory there have been similar trends of changes in consumption patterns with a pronounced reduction of food and clothing and a gradual growth of shares for education and recreation, medical services, and communication and transportation, while the gap in the standard of living between urban and rural areas continued to widen. However, migration to urban areas contributed to a number of 5 serious problems. In particular, the urban housing shortage has been a dominant factor in contributing to poverty levels. The Housing Reform Policy launched in 1980 to solve the problems of urban housing shortages and poor housing conditions (Hubacek et al., 2007) promoted commercialization of the housing sector and private ownership, allowing people to buy their own apartments. At the same time, the government, state owned enterprises, domestic private companies and overseas developers invested significant funds into the urban housing development (Hubacek et al., 2007). In addition, the latest consumer items, such as air conditioners, personal computers, mobile phones and automobiles, which were previously only the sign of the wealthy part of the population, increased significantly as well (Feng et al., 2009). As a result, urbanization levels, new lifestyles, as well as the consumption of those new consumer items dramatically increased, therefore, giving rise to substantial problems related to rising pollution levels and, thus, they will signify that China will follow western trajectories with regards to CO2 emissions. In China, air pollution is a serious issue for the entire country. Particles smaller than 2.5 micron (PM2.5), may pass through the lungs to affect other organs, leading to health hazards such as heart disease, altered lung function and lung cancer. The concentration of PM2.5 in China is the highest in the world and air pollution is more pronounced in cities than in rural areas. From 2000 to 2010, the incidence of lung cancer in Beijing increased by 56.35%. China’s air pollution and CO2 emissions both contribute to an important part in global environmental changes. It is, thus, necessary for China to draw useful lessons from experiences in advanced economies in terms of reconciling population growth and environmental quality. Overall, population dynamics and lifestyle changes reflected upon consumption patterns are expected to substantially influence China's energy use and generated carbon emissions. The further investigation of these issues is expected to facilitate improvements in decision making for low carbon development. The paper is structured as follows: Section 2 reviews the literature, while Section 3 introduces methodological issues and data description. Section 4 presents the empirical analysis and, finally, Section 5 concludes the paper. 5 2. Literature review Most environmental degradation can be traced to the behaviour of consumers either directly, through activities like the disposal of garbage or the use of cars, or indirectly through the production activities undertaken to satisfy them (Daly, 1996; Duchin, 1998). Cultural and behavioural changes also affect energy use and carbon emissions. It is thus important to understand lifestyle changes in order to support urban planning policy making. Lifestyle factors may include societal values, norms, disciplines, cultural climate and others. Urbanisation in developing countries is likely to reshape household lifestyles in many cases, thus causing a shift in consumption behaviour (e.g. more intensive use of motorised vehicles or electric appliances and electronic devices). In general, the literature that investigates the relationship between population characteristics and carbon emissions has followed two major strands: One strand investigates the causalities and mechanisms of interaction between population characteristics and carbon emissions, and through the employment of statistical and econometric methodologies evaluates the impact of those population characteristics on carbon emissions. Lutzenhiser (1991) discusses different physical, economic, psychological and sociological models and points out that lifestyle research needs to take account the cultural perspective on household energy use. Knapp and Mookerjee (1996) discuss the nature of the relationship between global population growth and CO2 emissions through Granger causality tests. Their results document the absence of a long-term equilibrium relationship, and only the presence of a short-term dynamic relationship between CO2 emissions and population growth. Shui and Dowlatabadi (2003) indicate that a sectoral approach (categorization based on industrial, transportation, commercial, and residential sectors) is limited in its capacity to reveal the total impacts of consumer activities on energy use and its related environmental impacts proposed by the Consumer Lifestyle Approach (CLA) to explore the relationship between consumer activities and environmental impacts in the U.S. Their results highlight that more than 80% of the energy used and the CO2 emitted in the U.S. are a consequence of consumer demands and the economic activities to support these demands, while direct influences due to consumer activities (i.e., home energy use and personal travel) are 4% of the U.S. GDP, but they account for 28% and 41% of the U.S. energy use and CO2 emissions, respectively. Moreover, indirect influences (i.e., housing operations, transportation operations, and food) involve more than twice the direct energy use and CO2 emissions. Therefore, the characterization of both direct and indirect energy use and emissions is critical to the design of more effective 7 energy and CO2 emission policies. Satterthwaite (2009) investigates the CO2 emission levels in various nations for an extended time period (e.g., 1950 to 2005). His empirical findings indicate low association between rapid population growth and high emission increases, while Jiang and Hardee (2009) illustrate that consumption and production patterns across various population groups differ. However, a major drawback in these studies is that population size is the only demographic variable considered, while lifestyle trajectories and the role of urbanization are ignored. Hence, paying more attention to the variables of urbanization and lifestyle trends is an important necessity in investigating the impact of population on carbon emissions. The second mechanism is the effect of population growth-related emissions on deforestation. Birdsall (1992) concludes that reductions in population growth matter, but are not the key factor in levelling off carbon emissions. A different strand of the literature gives emphasis on the role of urbanization for carbon emissions. Satterthwaite (2009) considers the implications of population growth and urbanization for climate change. His empirical findings document that the dominant factor for higher greenhouse gas emissions is the increasing number of urban consumers along with their consumption levels. Poumanyvong and Kaneko (2010) empirically investigate the effects of urbanization on energy use and CO2 emissions. Their findings show that the impact of urbanization on carbon emissions is positive across all income groups, but that this effect is more pronounced in the middle-income group. The literature has also identified that urbanization affects the carbon cycle indirectly and directly by facilitating releases and absorptions of carbon dioxide (Hutyra et al., 2014). As cities grow, the concentration of population and concomitant changes in social, political, behavioural, and economic activities accelerates carbon releases through land use changes and increased use and consumption of energy and energy-related materials. Alternatively, urban vegetation can absorb carbon from the atmosphere and cities can temporarily store carbon in building materials and other infrastructure (Pataki et al., 2006). Although direct carbon sequestration by urban plants and soils is negligible as compared with urban carbon emissions, local cooling effects that reduce energy use can be also substantial (Pataki et al., 2011). In the strand of literature that focuses on the Chinese economy, there exists a significant number of studies investigating energy consumption and CO2 emissions (FisherVanden et al., 2004; Hubacek et al., 2007; Peters et al., 2007; Auffhammer and Carson, 2008; Guan et al., 2008; Lin et al., 2008). Pachauri and Jiang (2008) compare the household energy transitions in China and India by analysing aggregate statistics and nationally representative household surveys. The authors demonstrate that urban households in both countries consume 7 a disproportionately large share of commercial energy and are much further along in the transition to modern energy. Feng et al. (2009) trace lifestyle changes in China. Their descriptive statistics analysis shows that household consumption on a regional scale follows similar trajectories, driven by changes in income and the increasing availability of goods and services. They also find that technological improvements have not been capable of fully compensating for higher emissions levels due to population growth and increasing wealth. Li and Li (2010) by making use of data from 30 Chinese provinces, explore how the population structure and technology levels impact carbon emissions. Their findings display that the population driver affects positively carbon emissions, while Wang (2010) finds both positive (i.e., GDP per capita, population size, family income) and negative (i.e., energy intensity, transportation average length of transportation routes, residential energy intensity) effects on carbon emissions. Du et al. (2012) investigate the driving forces, emission trends and reduction potentials of China's CO2 emissions. Their empirical findings document that economic development, technology progress and industry structure are all the most important factors affecting China's carbon emissions, while the impact of energy consumption structure, trade openness and urbanization level is negligible. Their scenario simulations show that CO2 emissions in China will increase continuously up to 2020, but the reduction potential is significant. Finally, Zhu and Peng (2012) examine the impact of population size, population structure, and consumption levels on carbon emissions. By making use of a ridge regression model and expanding the stochastic impact on population, affluence, and technology, they highlight empirical findings revealing that changes in both consumption levels and population structure are the dominant drivers for carbon emissions. It is shrinking household sizes that significantly contribute to higher levels of residential consumption, resulting in higher carbon emissions. 3. Data and methodology This study makes use of annual data spanning the period 1978-2012, obtained from various sources, including United Nations (UN) Population Division, World Bank’s World Development Indicator database, National Bureau of Statistics of China (NBS), International Energy Agency, U.S. Energy Information Administration (EIA), and UN Food and Agriculture Organisation. The Appendix summarises the sources of data, while Table 1 provides a number of descriptive statistics in relevance to all the variables used in the empirical analysis. 9 In terms of the methodological approaches used, we first specify a log-linear model to estimate the determinants of per capita CO2 emissions in China. In this version we do not include disaggregated lifestyle consumption, only aggregate consumption. ln(PCO2)t = a + b1 ln(PCY)t + b2 ln(PCY)2t + b3 ln(URB)t + b4 ln(TRAD)t + b5 ln(CONS)t + ut (Model 1) where, PCO2 denotes per capita carbon missions, PCY is per capita income, URB is the urbanization measure, TRAD defines trade openness, CONS denotes total population consumption and, finally, u is the error term. In addition, we test the impact of both urbanization and lifestyle consumption through a model that explicitly introduces the two major components that dictate lifestyle consumption, i.e. housing (HOUS) and motor vehicle (MOTOR) expenses. The new model yields: ln(PCO2)t = a + c1 ln(PCY)t + c2 ln(PCY)2t + c3 ln(URB)t + c4 ln(TRAD)t + c5 ln(MOTOR)t + c8 ln(HOUS)t + ut (Model 2) Next, given that the economic system is commonly characterised by inertia, i.e. the effect of a random exogenous shock in previous periods may be carried over through a time path, although the behaviour of the economy is mainly influenced by explanatory factors during the current period (Hill et al., 2008). This characteristic is also relevant in our modelling framework. Carbon emissions at time t are inherently correlated with the emissions levels during a certain time period k precedent time t due to the strong inertia of their technical and urban infrastructures. For instance, it is impossible or extremely costly to replace all the power plants and freight infrastructure or remove all the private vehicles from expressways overnight. Upgrading road transport network turns out to be extremely capital and time intensive process. Thus, we proceeded to estimate the model by modifying explicitly introducing carbon dioxide lags. This allows us to draw further conclusions about the shortand long-term impacts of urbanization and lifestyle consumption on carbon emissions. The new version of the model yields: 9 ln(PCO2)t = a + b1 ln(PCY)t + b2 ln(PCY)2t + b3 ln(URB)t + b4 ln(TRAD)t + b5 ln(CONS)t + b6 ln(PCO2)t-1 + b7 ln(URB)t-1 + b8 ln(CONS)t-1 + ut (Model 3) and ln(PCO2)t = a + c1 ln(PCY)t + c2 ln(PCY)2t + c3 ln(URB)t + c4 ln(TRAD)t + c5 ln(MOTOR)t + c6 ln(HOUS)t + c7 ln(PCO2)t-1 + c8 ln(URB)t-1 + c9 ln(MOTOR)t-1 + c11 ln(HOUS)t-1 + ut (Model 4) Finally, we will examine how a number of demographic changes contributes to the evolution of carbon intensity. To this end, we add life expectancy (LIFE), fertility (FERTILITY) as well as three age variables representing the population up to 14 years old (POP14), the population between 15 and 64 years old (POP1564) and finally, the population above 64 years old (POP>64). This form of the model yields: ln(PCO2)t = a + b1 ln(PCY)t + b2 ln(PCY)2t + b3 ln(URB)t + b4 ln(TRAD)t + b5 ln(FERT)t + b6 ln(CONS)t + b7 ln(LIFE)t + b8 ln(POP14)t + b9 ln(POP1564)t + b10 ln(POP>64)t + ut (Model 5) and ln(PCO2)t = a + c1 ln(PCY)t + c2 ln(PCY)2t + c3 ln(URB)t + c4 ln(TRAD)t + c5 ln(FERT)t + c6 ln(LIFE)t + c7 ln(MOTOR)t + c8 ln(HOUS)t + c9 ln(POP14)t + c10 ln(POP1564)t + c11 ln(POP>64)t + ut (Model 6) 11 4. Empirical analysis 4.1. Unit Root Testing To test the stationarity properties of the variables involved in the modelling process, we make use of two modified Dickey–Fuller tests with good power. These are the DF-WS test, proposed by Park and Fuller (1995), making use of the WSLS estimator, which is more efficient than the OLS estimator in estimating autoregressive parameters, and the DF-GLS test, proposed by Elliot et al. (1996), which analyses the sequence of Neyman–Pearson tests of the null hypothesis of the presence of a unit root. The results are reported in Table 2. They indicate that all the variables are integrated of order one. [Insert Table 2 about here] 4.2. Cointegration Testing and Estimates Next, Johansen and Juselius (1990) cointegration tests are performed in the cases of Models 1, 2, 5, and 6. They reveal evidence in favour of cointegration between carbon emissions and the above mentioned control variables across all versions of the modelling approach. The cointegration results are reported in Table 3. Both the eigenvalue test statistic and the trace test statistic indicate that there is a single long-run relationship across the variables under study as well as across the various versions of the model examined. [Insert Table 3 about here] Once the presence of a cointegrating relationship is established, the analysis is carried out by obtaining the estimations of the cointegration vector. In particular, normalizing the cointegration vector on carbon emissions, we obtain the estimates reported in Table 4. [Insert Table 4 about here] GDP growth is illustrated to exert a strong impact on CO2 emissions, reflecting both the income effect and the specificity of industry dominance in China’s economic growth model. The negative sign of squared GDP growth is in accordance with the diminishing marginal income effect, indicating the presence of an inverted-U shaped Kuznets effect associated with income and suggesting that China is in a position to mitigate the negative spillovers from carbon emissions and air pollution as the country gets more affluent. Our results are in accordance to those reached by de Leon Barido and Marshall (2014) who provide supportive 11 evidence for the positive association between income/level of development and carbon emissions across many countries. Urbanisation is also shown to contribute to carbon emission intensity per capita in a positive manner. This is mostly due to the presence of a higher demand for goods and services supplied as well as lifestyle changes. The positive effect of urbanization on carbon emissions indicates that China is not characterized by strong environmental policies, therefore, underscoring the importance of pollution problems. Our results receive statistical report by those in Elliott and Clement (2014) who provide empirical evidence about the strength of urbanization in leading to higher levels of carbon emissions. These findings strongly indicate that urbanization requires substantial and ongoing inputs related to energy and other sectors, which seems to occur through highly inefficient and environmentally destructive means. The three major characteristics associated with urbanization, i.e. population concentration, landscape transformation and systematic interaction, all seem to be substantially conducive to the positive impact on carbon emissions. In terms of lifestyle consumption, the effect on carbon emissions is also positive. Higher levels of such consumption by Chinese households indicate that these households tend to consume more electronics and electrical appliances as a result of becoming more affluent, indicating a spillover effect on carbon emissions growth. Our findings are in accordance with those provided by Wei et al. (2007) who suggest that a very high percentage of higher energy production and their spillover effects on carbon emissions are a consequence of people’s lifestyles, and the economic activities that support these demands. Both urbanization and changing lifestyles lead to more energy intensive consumption, shaped by the familiar western societies and values brought via the mass media. The analysis also shows that population variables are significantly important as influential drivers for carbon emissions. In addition, both extended life expectancy and an ageing population has negative impacts on per capita emissions, indicating that older people generally have lower consumption of energy intensive goods and services than people in younger generations, highlighting again the importance of the lifestyle driver for carbon emission projections. With respect to the population variables, our findings seem to be receiving statistical support by Shi (2003) and Cole and Neumayer (2004) who find a firm positive relationship between population changes and carbon dioxide emissions, mostly due to higher demand for energy consumption. Extended life expectancy leads to lower carbon intensity, whereas fertility declines over the last five decades seem to contribute to increasing carbon intensity. These two 13 findings have significant policy implications for China’s demographic and environmental policy. The literature has provided mixed results. For instance, O’Neill and Chen (2002) provide evidence for the U.S., showing that the increase in the life expectancy increase residential energy use, while it decreases transportation energy use, with substantial consequences for carbon emissions. By contrast, Fan et al. (2006) generate conclusions similar to ours, given that their study documents a negative impact on CO2 emissions for countries with high income and a positive impact for countries at other income levels. The demographic shift has complex effects on carbon emissions intensity changes. The positive sign of the fertility driver suggests that the demographic changes over the next decades will continue to increase carbon intensity across the Chinese cities, as the general trend would be higher levels of life expectancy and a declining child-bearing rate, as a result of economic development. In effect, both fertility and lifetime variables embody the underlying lifestyle and consumption patterns changes driving carbon emissions upward. The findings on the positive association between fertility and carbon emissions find empirical support by Stephenson et al. (2010) who document that although the contribution of highfertility countries to global carbon emissions is low, it is increasing with the economic development it needs to reduce their poverty levels. Rapid population growth endangers the capacity of these communities to adapt to climate changes. Significant mass migration, mostly to urban areas, occurs as a response to climate changes and should be regarded as a legitimate response to the effects of such climate changes. 4.3. Robustness Checks: Instrumental Variables (IV) Estimates Finally, to avoid potential endogeneity problems across our primary variables under study, i.e. carbon dioxide, urbanization and lifestyle consumption, in estimating models 3 and 4, we make use of the instrumental variable least squares (IVLS) methodological approach. In the presence of endogeneity, OLS estimators are inconsistent and biased. Nevertheless, the choice of a valid instrument is always a complicated task. The results appear in Table 5 and are based on White’s standard errors to avoid potential problems of heteroskedasticity. They also remain robust across both models. All variables show the expected sign, while they are statistically significant at the 1% level. The empirical findings are similar to those obtained in Table 4. There also exists a lagged income effect. In particular, it is also interesting to note that the long-run income elasticity of carbon emission is higher than its short-run counterpart, suggesting that China would be less capable of controlling the carbon dioxide problem as the 13 country becomes more affluent; in other words, carbon intensity would increase at a faster pace in the longer run, unless a number of serious policy responses are undertaken soon that will eventually mitigate the pollution problem. [Insert Table 5 about here] 5. Conclusions and policy implications This paper examined the impacts of population structure, urbanization and consumption life-style changes on carbon emissions in China from 1978 to 2012. Through the methodologies of cointegration and instrumental variables (IV) the empirical analysis managed to rectify the positive influence of urbanization, consumption life-style, population structure, fertility and life expectancy on carbon emissions. Policymakers should find a way to control emissions without sacrificing standards of living. The empirical analysis revealed that the population structure played a highly significant role in affecting carbon emissions. Therefore, policies that respond to changes in urbanization level and age structure should be also seriously considered, given that China will continue to undergo urbanization in the next several decades, and the pressure of emission increase to grow will be stronger. Policy makers in China have reoriented their policies towards urbanization from ‘control the scale of large cities, rationally develop medium cities, and actively develop small towns’ to ‘develop large, medium, and small cities in a synchronized manner and form city groups with large radiation effects’. This conversion reflected the awareness of the vital function of concentrating the use of resources and environmental treatment in large-scale or medium-scale cities. Policymakers should more strongly emphasize the assembly and scale effects of cities to reduce emissions and initiate low carbon development. The working age population profile also indicates that the trend of population aging will be the major characteristic of China's age structure in the future. Given this backdrop, the empirical findings imply that changes in the age structure will present an alleviationdominant impact on carbon emissions in the future. In terms of consumption life-styles and experiencing a shift from household budgets dominated by expenditures on food and clothes to increasing shares of expenditures for services, housing and luxury items, such as automobiles, driven by changes in income and the increasing availability of goods and services, China will keep following ascending trajectories regarding CO2 emissions. Based on those findings, there is a lot of room for improvement on the consumer side as well as an awareness of the interaction of infrastructure and consumption. Future expenditures and 15 consumer behaviour depend to a large extent on the infrastructure that is built today. Consumers' choices are bound by the availability of alternatives (i.e., public transportation). Thus, the trajectory of future emissions needs to be addressed by the infrastructure choices of today (Hubacek et al., 2007). In terms of the consumption items, there are only a few alternatives in sight as Chinese consumers try to emulate Western lifestyles and thus, inadvertently, western levels of emissions. Overall, policies regarding urbanization and derived residential consumption will extensively influence carbon emission trends. Policymakers should immediately initiate overall planning for population development and residential consumption by establishing the necessary assessment frameworks and guidance systems that promote low carbon development in China. For instance, policies directed to enhance efforts to target home energy reduction should focus on building attributes. Such efforts should focus on changing behaviours by taking an approach that makes efficiency more convenient, increases motivation, and provides more actionable and pertinent information (Carrico et al., 2011). Therefore, an effective reduction in energy use and emissions will come from building efficiency, energy conservation actions based on human behaviours, and conservation education. Discussions around the processes of urbanization should incorporate the political discourses surrounding fossil fuels, land use, and lifestyle choices when accounting for pollutants. Recent research has examined the politics and power dynamics engaged in resistance to low-carbon transitions (Geels, 2014). A directed effort to embed studies of energy consumption in the political and institutional aspects of urbanization is necessary. A greater deployment of policy analysis tools, methods, and theoretical approaches would substantially contribute to an improved understanding of the way policy interventions try to accomplish in a mission to influence the trajectory of urbanization as it relates to both energy use and carbon emissions. Appendix Data sources Data series Population (total, by age group) Life expectancy Fertility GDP ( PPP, MER) Source UN population division WDI UN, WDI WDI 15 Urbanisation Per capita GDP Trade openness Export/import Energy consumption Energy productivity (GDP/energy) Electricity production and consumption Energy price (oil) CO2 emissions PM10 Meat consumption (mutton, pork, beef) number of motor vehicle per capita WDI WDI WDI WDI WDI, EIA, IEA WDI WDI, EIA, IEA EIA, BP IEA, WDI WDI FAO , research publications NBS, research publications References Auffhammer, M., Carson, R.T., 2008. Forecasting the path of China's CO2 emissions using provincelevel information. Journal of Environmental Economics and Management 55, 229-247. de Leon Barido, D.P., Marshall, J.D., 2014. Relationship between urbanization and CO2 emissions depends on income level and policy. Environmental Science and Technology 48, 3632-3639. Bin, S., Dowlatabadi, H., 2005. 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Dev. _______________________________________________________________________________ Fertility 3.07681 2.69600 0.00000 6.16100 1.69880 Per capita GDP 6.05826 5.95215 4.44869 8.11612 1.10851 Per capita CO2 7.53933 7.59504 6.35291 8.80373 0.68783 Per capita motor vehicles 3.57647 3.57521 1.29048 6.58893 1.60998 Urbanization 3.24792 3.17562 2.80817 3.94692 0.37380 Consumption 530.186 460.141 143.8334 1229.966 311.319 Life expectancy 65.2392 68.4617 0.00000 75.04200 12.1210 Squared per capita GDP 37.9076 35.4303 19.79090 65.87140 13.8380 Housing 32030.4 9750 1103 159313 43402.3 Trade openness 33.5788 31.6746 5.31418 70.56707 18.8394 Popul. up to 14 31.2878 30.1907 17.98437 41.13266 7.75763 Popul.15-64 63.0201 64.1573 55.24876 73.50738 6.27837 Population>64 5.69216 5.65193 3.618581 8.679630 1.49548 __________________________________________________________________________ 21 Table 2 Unit root tests ___________________________________________________________________________ Variable DF-WS test DF-GLS test ___________________________________________________________________________ co2 -1.20(3) -1.18(3) Δco2 -5.46(2)* -5.73(2)* pcy -1.34(3) -1.30(3) Δpcy -5.27(1)* -5.58(2)* 2 pcy -1.32(3) -1.26(4) Δpcy2 -5.30(2)* -5.81(3)* urb -1.18(4) -1.14(3) Δurb -5.83(2)* -6.16(2)* trad -1.15(3) -1.09(3) Δtrad -5.76(2)* -5.96(1)* fert -1.26(3) -1.21(3) Δfert -5.28(2)* -5.62(1)* life -1.29(4) -1.17(3) Δlife -6.11(2)* -6.58(1)* motor -1.35(3) -1.24(3) Δmotor -6.24(1)* -6.46(2)* hous -1.37(3) -1.28(3) Δhous -5.69(2)* -5.87(1)* pop14 -1.24(3) -1.15(3) Δpop14 -5.11(1)* -5.47(2)* pop1564 -1.29(4) -1.20(3) Δpop1564 -5.48(3)* -5.72(1)* pop>64 -1.18(3) -1.12(3) Δpop>64 -5.39(2)* -5.85(1)* ___________________________________________________________________________ Notes: Small letters indicate variables in logarithms. Δ indicates first differences. Numbers in parentheses denote the optimal number of lags used in the augmentation of the test regression and were obtained through the Akaike criterion. * indicates the rejection of the unit root null hypothesis at 5%. 21 Table 3 Cointegration tests ___________________________________________________________________________ r n-r ml 95% Tr 95% ___________________________________________________________________________ Model 1: Lags = 4 r=0 r=1 48.914 40.219 95.773 86.544 r≤1 r=2 33.209 34.397 72.329 75.328 r≤2 r=3 23.549 28.167 49.806 53.347 r≤3 r=4 18.741 21.894 30.163 35.068 r≤4 r=5 10.844 15.752 14.395 20.168 r≤5 r=6 2.356 9.094 2.356 9.094 Model 2: Lag = 3 r=0 r=1 r≤1 r=2 r≤2 r=3 r≤3 r=4 r≤4 r=5 r≤5 r=6 r≤6 r=7 57.893 38.429 31.936 21.883 16.126 10.249 2.014 51.258 40.219 34.397 28.167 21.894 15.752 9.094 109.852 82.315 70.308 45.627 29.318 12.537 2.014 102.326 86.544 75.328 53.347 35.068 20.168 9.094 Model 5: Lag = 3 r=0 r=1 r≤1 r=2 r≤2 r=3 r≤3 r=4 r≤4 r=5 r≤5 r=6 r≤6 r=7 r≤7 r=8 r≤8 r=9 r≤9 r=10 r≤10 r=11 110.935 81.637 65.328 52.624 40.925 31.863 24.658 20.326 15.637 8.924 1.452 95.962 84.007 72.549 60.016 51.258 40.219 34.397 28.167 21.894 15.752 9.094 226.547 160.836 124.702 105.863 90.725 69.527 52.831 36.725 19.836 9.711 1.452 197.435 172.814 146.739 129.817 102.326 86.544 75.328 53.347 35.068 20.168 9.094 23 Model 6: Lag = 2 r=0 r=1 126.594 118.753 248.994 231.709 r≤1 r=2 87.515 95.962 157.782 197.435 r≤2 r=3 80.005 84.007 139.613 172.814 r≤3 r=4 59.814 72.549 115.204 146.739 r≤4 r=5 51.426 60.016 101.316 129.817 r≤5 r=6 38.515 51.258 87.515 102.326 r≤6 r=7 28.371 40.219 64.714 86.544 r≤7 r=8 22.810 34.397 49.005 75.328 r≤8 r=9 17.626 28.167 31.139 53.347 r≤9 r=10 13.711 21.894 15.638 35.068 r≤10 r=11 8.427 15.752 4.119 20.168 r≤11 r=12 0.246 9.094 0.246 9.094 ___________________________________________________________________________ Notes: r is the number of cointegrating vectors, n-r is the number of common trends, ml = maximum eigenvalue statistic, Tr = Trace statistic. The number of lags was determined through Likelihood Ratio tests, developed by Sims (1980). 23 Table 4 Long-run estimates – Models 1, 2, 5, and 6 ___________________________________________________________________________ Variables Model 1 Model 2 Model 5 Model 6 __________________________________________________________________________ Intercept 0.964 0.873 1.006 0.993 (1.09) (0.94) (1.32) (1.08) pcy 0.438* 0.416* 0.386* 0.392* (6.58) (6.24) (6.14) (5.84) pcy2 -0.061* -0.048* -0.042** -0.039** (-4.13) (-3.86) (-2.64) (-2.75) urb 0.228* 0.215* 0.204* 0.211* (6.19) (6.42) (5.91) (6.09) trad 0.185* 0.172* 0.153* 0.162* (5.61) (5.28) (5.09) (5.46) cons 0.307* 0.258* (6.53) (5.63) motor 0.195* 0.173* (5.41) (5.29) hous 0.158* 0.129* (5.26) (5.14) fert 0.116* 0.093* (5.18) (4.95) life 0.084* 0.069* (5.28) (5.02) pop14 0.249* 0.226* (6.15) (5.94) pop1564 0.191* 0.174* (6.03) (5.82) pop>64 0.072** 0.046** (2.61) (2.37) Diagnostics R2 LM 0.62 [0.32] 0.57 [0.28] 0.64 [0.38] 0.69 [0.41] 25 RESET [0.24] [0.22] [0.31] [0.35] ___________________________________________________________________________ Notes: Numbers in parentheses denote t-statistics. LM and RESET are tests for serial correlation and model functional misspecification, respectively. Figures in brackets denote p-values. *, ** denote significance at the 1% and 5% statistical levels, respectively. Table 5 IV Estimates – Models 3 and 4 ___________________________________________________________________________ Variables Model 3 Model 4 __________________________________________________________________________ Intercept 0.758 0.762 (1.16) (1.03) Δpcy 0.393* 0.377* (6.15) (5.86) 2 Δpcy -0.053* -0.042* (-4.28) (-3.59) Δurb 0.214* 0.192* (6.35) (6.28) Δtrad 0.167* 0.151* (5.83) (5.58) Δcons 0.348* (6.61) Δmotor 0.226* (5.80) Δhous 0.184* (5.71) Δco2(-1) 0.583* 0.514* (6.17) (5.92) Δurb(-1) 0.086* 0.064* (5.29) (5.11) Δcons(-1) 0.118* 0.103* (6.03) (5.82) Δmotor(-1) 0.095* (5.68) Δhouse(-1) 0.047* (5.41) Diagnostics R2 Sargan 0.66 [0.28] 0.61 [0.24] 25 LM [0.25] [0.26] RESET [0.21] [0.18] ___________________________________________________________________________ Notes: The instruments used for Model 3 are: a constant, three lags of income, 4 lags of urbanization and 4 lags of consumption, while those for Model 4 are: a constant, 4 lags of income, 4 lags of urbanization, 3 lags of motor vehicle expenses and 3 lags of housing expenses. Sargan tests the null validity of instruments used. The remaining notes remain similar to those in Table 4.
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