Multidimensional effects decomposition of urbanization on energy 1 consumption based on a modified LMDI model

: Urbanization is important for population transfer, it triggers the coordination and adaptation process 6 among population, space and industries, which in turn have multiple effects on energy consumption (EC). This paper 7 conducted multidimensional effects decomposition of EC change in China (1998-2017) based on a modified LMDI 8 model. The findings revealed that urbanization has a greater pulling effect on EC of production side over life side. 9 Household consumption effect is the leading factor stimulating the increase in EC at production side. The 10 convergence of urban and rural residents' consumption behaviors has increasingly contributed to EC fluctuation at 11 life side, and become the handicap for energy sustainable development with population expansion. Unreasonable 12 land utilization from space aspect has intensified EC, however, the scale effect produced by population 13 agglomeration negatively caused fluctuation of living EC. The transformation and upgrading of traditional energy- 14 driven industries and technological progress have alleviated energy pressure, and the consumption inhibiting effect 15 has an inverted U-shaped effect on EC (promote first, decrease later). Thus, this paper further proposed that when 16 the development from industry aspect encounters bottleneck, more attention should be paid to improve residents' 17 consumption habits at population aspect, and release resource allocation momentum from space aspect to reduce EC.


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At present, China's urbanization has entered a period of rapid growth. The total number of large-21 scale cities has reached the first place in the world, and the urban population has accounted for 60% 22 of the country's total population. With the arrival of non-agricultural industries in urban areas and 23 the migration of rural populations to urban areas, urbanization has not only promoted the dual 24 transformation of manufacture and lifestyle, but has also led to an increasingly prominent problem 25 of energy consumption (EC) in urban development. From 1998 to 2017, China's urbanization rate 26 increased by 1.75 times, but behind it there is a 3.29 times increase in total EC. Related research 27 shows that urbanization exerts a number of influences on EC (Jones, 1991;Mrabet et al., 2019), as 28 the changes of consuming behaviors, expansion of land space and transformation of production 29 mode in China, creates increasing pressure on energy supply and the natural environment (Wang, 30 2014; , the EC level of an agricultural population transferred to a city will increase 31 to more than three times the original (Zhang et al., 2011). It can be seen that the current 32 urbanization model in China is characterized by high EC, and the energy problem is still a shackle 33 that restricts sustainable development. From a cross-country comparison, although China has had 34 over 660 million people relocating to cities and towns during its 40 years of rapid development, 35 there is still a gap of about 20 percentage points compared with the 80% urban rate in developed 36 countries. At the same time, the EC of Chinese residents is much lower than the world average, only 37 1/3 of the high level of urbanization in the United States and 1/2 of the United Kingdom (Wei and 38 (Sheng et al., 2017). For answer this question accurately, it is necessary to identify the affecting 48 factors and its mechanisms that drive EC in the process of urbanization in combination with the 49 specific development scenarios of the research samples, and to further quantify the direction and 50 intensity of different factors. 51 The contribution of this paper can be summarized in three aspects. 52 First, in terms of research perspectives, this research believes that the impact on EC should not 53 be considered only from a certain aspect of the urbanization process, but should be combined with 54 realistic development scenarios and consider the influence transmission mechanism of multiple 55 factors. Therefore, this research expands the existing research and constructed the impact 56 mechanism of population, space and industry on EC in the process of urbanization, discussed the 57 interaction path between them to support and supplement the existing economic development and 58 transformation theories, and can accurately identify EC trends, trends under urbanization and the 59 driving factors behind, and then further provide an analysis framework for subsequent in-depth 60

research. 61
Second, in terms of research models, the factor decomposition method has been widely adopted 62 in the literature of energy economics and environmental economics because of its applicability. 63 However, the existing research generally uses the form of "single multiplication and sum", which 64 limits the content covered by the expression to a certain extent, causes the homogeneity of the effect 65 analysis, and ignores more influencing factors. Therefore, this paper divides the total EC into 66 production EC and domestic EC, and combines the characteristics of the dual structure of urban and 67 rural areas and the difference in consumption between urban and rural residents, and innovatively 68 constructs a vector form based expanded Kaya identity model. This method improves the LMDI 69 method to the form of "multiple multiplication and summation", and analyzes the dynamic 70 contribution of population, space, and industry to the fluctuation of EC in the process of urbanization 71 in China. 72 Third, in terms of research data, some literatures use cross-sectional data to make static and 73 horizontal comparisons of EC between regions at a certain point in time, lacking a time series of 74 phased EC evolution analysis, and ignoring the nature of the dynamic changes of urbanization. 75 Therefore, this study adopts the panel data in China in the past two decades and conducts the 76 empirical analysis which uncovers the reasons of the dynamic changes in EC during the process of 77 urbanization. On the one hand, it can provide scientific basis and policy recommendations for 78 analyzing EC issues under China's new urbanization. On the other hand, the dynamic trends and 79 transition that are in the early stages or in the process of urbanization. 81 The remainder of this paper is organized as follows. A brief overview of the existing literature 82 regarding EC in the process of urbanization is presented in section 2 with respect to three aspects of 83 population, space and industry, further reveals the effect mechanism between them. The proposed 84 Methodology is elaborated in section 3 for a modified LMDI model and a definition of the new data 85 source and variables. Our main findings are demonstrated and discussed with an empirical analysis 86 in Section 4. Finally, we conclude in Section 5 with three policy recommendations. 87 2. Literature review and effect mechanism reveal 88

Literature review 89
The effect of urbanization on EC cannot be simply limited to the impact of changes in the proportion 90 of urban and rural populations, as there must be a complex transmission mechanism formed by the 91 interaction of many factors (Avtar et al., 2019). By reviewing the existing literature, it is found that 92 industrial structure, spatial arrangement and household consumption are the three main factors. 93 The study literature in population aspect shows that urbanization is not only the simple process 94 of residents moving from rural to urban areas, but more significantly the process of changes in 95 consumer behavior and improvement of human capital, of which the influences on EC can be 96 roughly divided into two categories: on the one hand, the development of population urbanization, 97 as an intensive development method, has a clustering effect and a scale effect on the improvement 98 of energy efficiency and the promotion of efficient energy utilization technologies (Chen et al.,99 2019), further lower the original rural EC structure which mainly based on the fuel wood and straw 100 (Yang et al., 2019) , which can reduce EC to a certain extent. At the same time, the improved 101 awareness of energy conservation and the rising energy prices can also lead to a continuous decrease 102 in energy intensity (Kambara, 1992). On the other hand, population urbanization has promoted the 103 increase of residents' consumption levels. Khuong et al., (2019) pointed that the way in which 104 urbanization impacts EC depends strongly on the income level of the country studied. Cities have 105 richer energy equipment and consumption types, which greatly changed the EC behavior and 106 lifestyle of the immigrant families (Liu and Lei, 2018). With the upgrading of the consumption 107 structure of urban residents, the EC in the production of goods and services has been indirectly 108 promoted (Bin and Dowlatabadi, 2005), which has gradually become a major factor in the EC of 109 EC has also caused scholars to question the development of compact space (Rudlin and Falk, 1999). 135 Research from the perspective of industrial development shows that productive EC in urban areas 136 is significantly higher than that in rural areas (Li and Lin, 2015), and changes in industrial structure 137 at different stages of urbanization have different paths to EC (Mukhopadhyay and Forssell, 2005): 138 the biggest influencing factor affecting China's urbanization process is the industrial structure (Lu, 139 1999), of which the secondary industry accounts for the largest proportion of total EC (Lv et al.,140 2019), with the development of urbanization, the ratio of light industry to heavy industry has 141 changed significantly. The industrial focus has shifted from energy-dependent manufacturing to 142 environmentally friendly high-end technology industries. The upgrading of industrial structure 143 causes energy intensity to decline continuously over time (Fishervanden et al., 2004). However, 144 some scholars pointed out that the effect of industrial structure changes on energy efficiency has 145 gradually disappeared since the mid-1990s, and it is difficult to cope with the current huge energy 146 pressure by structural adjustment alone (Shi and Zhang, 2003). Further studies showed that the 147 influences of industry technological advance on EC present noticeable differences in different 148 development phases (Ji and Chen, 2017). At present, we should depend on technological innovation 149 to realize the energy intensity reduction and energy efficiency improvement (Adom and Kwakwa, the total EC will depend on the net effect of technological progress. 154

Effect mechanism reveal 155
Based on the literature review, in the process of urbanization, population migration promotes the 156 transfer and interaction of people and materials between regions. To be specific, at the micro level, 157 urbanization directly affects people's lifestyles such as consumption, shopping, transportation and 158 travel, and promotes the coordinated development of low-energy-consumption tertiary industries. 159 At the macro level, urbanization also resets the spatial layout of the elements required for industrial 160 development, provides input of manpower, land and other elements for industrial development, and 161 broadens the consumer market for products. It is also helpful for large-scale planting after the land 162 is transferred, and provides an opportunity for the development of modern agriculture. Thus, there 163 will be the following complicated effect transmission mechanism of EC in urbanization process 164 the side effect is that while feeding back the development of other economic units, it will also cause 176 a rebound in total energy demand. 177 To sum up, academia has done extensive and useful research in the field of urbanization on EC 178 and its influencing factors, but there is still some gap for further research. This study believes that 179 the impact on EC should not only be considered from a certain aspect of the urbanization process, 180 but should be combined with realistic development scenarios and consider the interaction 181 transmission mechanism of multiple factors. Hence, based on the multidimensional mechanism of 182 urbanization for EC established above, the traditional effects decomposition method needs to be 183 improved to cover more influence factors to quantify and decompose the influential effect of three 184 aspects including population, space and industry on EC in urbanization process, further compare 185 and dissect the directions and intensities of various effects. Kaya identity (Kaya,1989), then improved the LMDI method proposed by Ang (2004) to further 197 enrich the influencing factors covered by the function. The EC impact model constructed based on 198 the influence and effect transmission mechanism as in Equation (1): 199 E is the total energy consumption, EP is the amount of EC in production (i=1, 2, 3 respectively 201 represent the primary industry, secondary industry and tertiary industry), EL is the amount of EC in 202 daily life (u, r= respectively represent the urban and rural), G is the gross domestic product (GDP), 203 HC is the household consumption, P is population quantity, and A is land area. Household 204 consumption is incorporated into the production EC impact formula in order to reflect the impact of 205 consumption demand on the indirect EC of the production side. Additionally, space expansion is 206 also incorporated into the EC impact formula to reflect the impact of space layout on the direct EC 207 of residents. Considering the differences of separate urban-rural structure in urbanization process of 208 China, the further vector decomposition of household consumption is shown as Equation (2) Perform differential conversion on the left side and right side of the plus sign in equation (4), and 227 the following functional formulas can be obtained: 228 Pu and Pr indicate the number of urban and rural populations respectively, 229 In Equation (5) , respectively indicate the 232 proportions of urban and rural residents' total consumption in total residents' consumption. The 233 influence equation of total energy consumption can be derived as Equation (7) which can reflects 234 the urban-rural dual structure of energy consumption in the process of urbanization. 235 Based on previous work (Li and Yang, 2014), we decomposes Equation (7)    this not only reflects the operating status of the regional economy, but also reflects changes in the 266 environment, concepts and policies of EC. Urbanization is usually reflected through the proportion 267 of urban population in the total population. In terms of regional spatial expansion, this study selects

Empirical results and analysis 272
The urbanization rate of China risen from 33.35% to 58.52% between 1998 and 2017, 397 million 273 people moved to cities during the period, with an average annual growth rate of 3.59%.    we can predict that with the deepening of urbanization, more urban residents will expand their 343 demand for non-food commodities. This will undoubtedly become the main factor to promote EC 344 at the production end in the future. 345 From specific analysis of the impact of demographic factors on EC fluctuations at life-side, the 346 difference in lifestyles and living standards between urban and rural residents in the early days 347 resulted in very different energy utilization and consumption behaviors. In 1998, the ratio of urban 348 and rural living EC per capita was as high as 3.07, however, the improvement of residents' living 349 standards is accompanied by the homogenization of consumption behaviors between urban and rural 350 areas. The substantial increase in rural EC has caused the urban rural per capita EC ratio to drop 351 year by year to 0.99 in 2017, and the EC gap in living has almost disappeared ① . Therefore, the 352 urbanization structure effect is not the major influence factor, but the per capita life effect (national 353 EC per capita) has the highest contribution to the variation of life EC. In addition, due to the previous 354 one-child policy, the rate of population change was relatively low, and the growth rate remained at 355 around 0.5% for many years, thus the current positive contribution to production EC is low. 356 However, with the implementation of China's two-child policy in 2016, a substantial increase in 357 population is likely to provide a broader consumer market for industrial development, and thereby 358 provide a stronger driving force for EC. 359

Effects decomposition from space aspect 360 ①
Non-commercial energy such as firewood, straw, and biogas in rural may account for a large proportion of the EC structure, and this part is not reflected in official statistics, thus the rural life EC may be underestimated. agglomeration density effect of space is accumulated to contribution degree of -8.16% to the total 363 EC. The scale effect of energy utilization caused by the population agglomeration is apparent, which 364 relieves energy pressure to a certain extent. On the contrary, the positive contribution of the spatial 365 expansion effect to the total EC is 9.18%, which exceeds the EC saved by the density agglomeration 366 effect. On the whole, the space expansion in urbanization process of China has promoted the EC. 367

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The reason is that with the expansion of population activity space in the process of urbanization, 369 both the natural and socio-economic attributes of the land will change. Since 1998, the China has 370 continued to optimize and adjust urban housing and land-use policies, the urban built-up area 371 increased by 162.98% during the inspection period, which was much higher than the 95.51%  The consumption inhibiting effect has the positive contribution degree of 6.19% to production EC 397 in total, but from the overall trend, the inhibiting effect on EC is increasingly enhancing. An 398 important point that should not be ignored is that the effects of technological progress and structural 399 adjustment have rebounded in recent years, and the effectiveness of alleviating EC is weakening. 400 short term, so industrial development must never be the only way to reduce EC. 420 The production effect in the process of urbanization has promoted EC. This is mainly due to the 421 expansion of the consumption market after the migration of rural populations to cities, which 422 indirectly stimulated EC at the production side. This point is in sharp contrast with the conclusion 423 of the urbanization structure effect on the life side mentioned above, indicating that the urbanization 424 rate has a much greater effect on the EC of the production side than on the daily life side. The (1) On the whole, with the development of urbanization, the total energy consumption of China has 446 been rising. The average annual growth rate of urbanization in China within the inspection 447 period is higher than the average annual growth rate of total energy consumption, and the 448 process of urbanization in China has accelerated energy consumption. From the perspective of 449 variation range, although the variation amount of production energy consumption is 6.80 times 450 of the one of living energy consumption, it presents the tendency of decreasing year by year. 451 From the perspective of growth multiples, the growth rate of energy consumption from daily 452 life is higher than that from production side, and the gap is increasing year by year. Therefore, 453 the domestic energy consumption in the process of urbanization in China is more worthy of 454 attention. 455 (2) From the population aspect, we conclude that the rise of energy consumption in production side indicating that the restraining effect of these two factors will be bottlenecked in the short term. 477 Therefore, industrial development must not be the only way to reduce energy consumption. 478

Policy Recommendations 479
and ecology; On the other hand, we suggest to revitalize the space inventory, release industrial 501 space through urban renewal, and at the same time, to expand infrastructure compatibility, 502 improve the utilization rate of public facilities, avoid dysfunction and repeated construction, 503 develop a sharing economy, reduce commuting energy consumption, and reduce infrastructure 504 energy consumption and promote intensive living energy consumption. 505 (3) In the aspect of industry, it is advisable to strengthen resource and environmental constraints 506 and develop high value-added industries. The industries in the early stages of urbanization were 507 mainly labor-intensive and depended strongly on resources and the environment. The influx of 508 low-end labor and extensive industrial development have made the energy intensity much 509 higher than that of European and American countries, but the proportions of secondary industry 510 in GDP of those developed countries during the urbanization process have surpassed 55%, and 511 theirs high-tech industries have a prominent proportion and low energy consumption. Therefore, 512 the industrial development under the new urbanization process cannot simply reduce the 513 proportion of the secondary industry, instead, we must strengthen the environment and resource 514 restrains, upgrade development models, focus on industrial quality and efficiency, develop 515 high-tech industries and high-end service industries, and strive to achieve the decoupling of 516 economic development and energy consumption. 517

-Ethical Approval and Consent to Participate 518
Not applicable, this manuscript does not report on or involve the use of any animal or human data 519 or tissue. 520

-Consent to Publish 521
Not applicable 522

-Authors Contributions 523
Xiang Yan contributed to the conception of the study, analysis and manuscript preparation. 524 Yongchun Huang helped perform the analysis with constructive discussions. 525 All authors read and approved the final manuscript.