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"ENVIRONMENTAL EFFICIENCY OF GREEN TRANSPORTATION UNDER THE
BELT AND ROAD INITIATIVE: AN EMPIRICAL STUDY"
Bukhara State University
Faculty of Economics and Tourism 1st year student
Sanoyeva Ferangiz Yoshi kizi
Abstract:
This article studies the impact of green transport systems on environmental quality in
the context of economic infrastructure development within the framework of the ‘One Belt, One
Road’ initiative. The need to implement economic infrastructure projects in an environmentally
friendly manner is urgent today. The study uses a semi-experimental approach. The results show
that green transport, although a stabilizing factor for environmental quality, leads to an increase
in CO₂ emissions. This situation is explained on the basis of the theory of development
compatibility. In conclusion, the study highlights the following as a positive conclusion: the
development of green transport in developing countries reduces the increase in carbon emissions.
Keywords:
Green economy, sustainable development, ecological innovations, efficient use of
resources, air pollution, carbon footprint, renewable energy, environmental safety, bioeconomy,
economic efficiency.
Introduction.
The Belt and Road Initiative (BRI) is an innovative framework aimed at
promoting intercontinental economic cooperation, connectivity, and infrastructure development.
It requires in-depth research, considering its comprehensive impact on environmentally friendly
transport networks and sustainable environmental practices. It is essential to assess the potential
impact of the BRI on clean transport and the environment, including both positive and negative
impacts. The BRI will have significant impacts on land use, resource consumption, pollution
levels, and transport infrastructure.
. This study aims to explore the complex relationship
between green transport and environmental sustainability in BRI countries, and to provide useful
analysis for policymakers, urban planners, researchers, and stakeholders supporting sustainable
development. Green transport modes include electric vehicles (EVs), public transport systems,
bicycle and pedestrian infrastructure, renewable fuels and alternative energy sources, smart
transport systems, sustainable infrastructure, and carpooling services. Manufacturers are actively
engaged in EV research, battery technologies, charging infrastructure, and related services.
Public transport networks can enhance public use through smart mobility solutions, infrastructure
upgrades, and investment in new vehicles. Innovative transport systems optimize traffic flow,
reduce congestion, and minimize energy consumption.
. Sustainable infrastructure plays a key
1
[1] X. Chen, A. Guo, Z. Miao, P. Zhu, Assessing the performance of the transport sector within the global supply
chain context: decomposition of energy and environmental productivity, Appl. Energy 358 (2024) 122615,
https://doi.org/ 10.1016/J.APENERGY.2023.122615. [2] Q. Lu, K. Fang, R. Heijungs, K. Feng, J. Li, Q. Wen, Y. Li, X.
Huang, Imbalance and drivers of carbon emissions embodied in trade along the Belt and Road Initiative, Appl.
Energy 280 (2020) 115934, https://doi.org/10.1016/J. APENERGY.2020.115934. [3] C. Nedopil Wang, China Belt
and Road Initiative (BRI) Investment Report 2021, 2022.
2
[4] Z. Lv, W. Shang, Impacts of intelligent transportation systems on energy conservation and emission reduction
of transport systems: a comprehensive review, Green Technol. Sustain. 1 (1) (2023) 100002,
https://doi.org/10.1016/J. GRETS.2022.100002. [5] S. Singh, S.P. Upadhyay, S. Powar, Developing an integrated
social, economic, environmental, and technical analysis model for sustainable development usinghybrid multi-
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role in green transportation through practices such as the use of recycled materials and
consideration of environmental impacts at the design stage, especially in the construction of
environmentally friendly roads and bridges. In addition, car-sharing services (ridesharing and
carpooling) reduce the total number of vehicles, reduce emissions, and alleviate traffic
congestion. Environmental degradation and climate change have a wide-ranging impact on the
world, including BRI countries. Despite the fact that more than 200 countries that signed the
Paris Agreement in 2015, including BRI countries, aimed to keep global temperature increase
below 2 °C, in 2017, carbon dioxide (CO2) emissions from BRI countries amounted to 11.76
billion tons, equivalent to 35.61% of global emissions. That is, their gross domestic product
(GDP) is still 17% The BRI countries, which have not yet reached the 2020 target, produce
almost a third of the world's carbon dioxide emissions. Reconciling economic growth potential
with low-carbon emissions has become a major challenge for BRI countries. According to "A
review on global fuel economy standards, labels and technologies in the transportation sector,
Renew", the transport sector is responsible for 15% of greenhouse gas emissions and 23% of
carbon dioxide emissions. In addition, the transport sector's contribution to carbon emissions
increased by 71% from 1990 to 2016, accounting for a quarter of global emissions. In particular,
the movement of goods accounts for 42% of CO2 emissions and is projected to reach 60% by
2050. Green transport can be a solution to reduce these emissions and support environmentally
sound practices within the BRI. Low- or zero-emission vehicles, such as By introducing EVs and
hydrogen-powered vehicles, BRI countries can reduce the negative environmental impact of
traditional transportation. This study examines how green transportation impacts the BRI
economies on their environmental footprints (resources used and waste generated), particularly
in terms of energy consumption and greenhouse gas emissions. Countries in transition to market
economies, often with high pollution and energy consumption, are also included in the BRI
economies. Green transportation can stimulate economic growth, reduce greenhouse gas
emissions, and support sustainable development. It also reduces air pollution, which is beneficial
to both the environment and human health. Research J.A.F. Machado, J.M.C. The Quantile
Moments method developed by Santos Silva was used to identify cross-sectional differences and
long-term changes between selected countries. The main reason why the development of green
transport systems has not achieved significant reductions in carbon emissions is the large
differences in the development stages of the BRI countries. In order to fully understand the
impact of green transport on environmental quality, it is important to deeply assess the
development stages of countries. Although green transport has the potential to improve
environmental quality, it has now become a task of "reducing CO2 emissions completely" rather
than "reducing CO2 emissions completely". This means that the introduction of green transport
systems has stopped the increase in emissions, that is, carbon emissions would have increased
even more strongly without these systems. In short, green transport systems have played an
important role in curbing the growth of CO2 emissions. This study also examines the role of
various control variables – such as innovation, domestic investment, institutional quality and
urbanization – in shaping environmental sustainability outcomes. Innovation is seen as an
important factor in promoting environmentally friendly technologies and practices, thereby
contributing to the reduction of ecological footprints. Empirical studies by show that countries
with high levels of innovation have lower carbon dioxide emissions, creating a more sustainable
environment. A key example in this context is innovation in renewable energy technologies;
studies by show the positive impact of innovation on promoting a sustainable environment by
reducing carbon dioxide emissions. In addition, domestic investment is an important driver in
promoting a sustainable environment and reducing negative environmental impacts. G.E. Halkos,
E.A. Paizanos, The channels of the effect of government expenditure on the environment:
evidence using dynamic panel data, found a positive relationship between the level of domestic
criteria decision making methods, Appl. Energy 308 (2022) 118235,
https://doi.org/10.1016/J.APENERGY.2021.118235.
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investment and improved environmental quality, as reflected in reduced carbon emissions and
lower air pollution. In support of these results, empirical studies by [31,32] have found that
increased domestic investment in environmentally friendly infrastructure, such as public
transport networks and renewable energy projects, can significantly reduce carbon emissions.
Institutional quality – that is, governance structures, policy frameworks and enforcement
mechanisms – is a key determinant of environmental quality. Strong institutional quality is
positively associated with environmental sustainability, and studies by S. Dasgupta, B. Laplante,
H. Wang, D. Wheeler, have shown that countries with stricter regulations and stronger
institutions have lower pollution levels and better environmental outcomes. Another study by S.
Dasgupta, B. Laplante, H. Wang, D. Wheeler, examined the relationships between institutional
quality, economic development, and environmental sustainability, and found that countries with
strong institutional foundations perform better on environmental indicators. Urbanization, on the
other hand, has been shown by extensive empirical studies to have negative impacts on
ecosystem functions and services, including habitat degradation, fragmentation, and biodiversity
loss. For example, a study by Seto, K.C., Davis, S.J., Mitchell, R.B., Stokes, E.C., Unruh,
examined the ecological impact of global urban footprints, noting that urban areas have high
levels of energy consumption, carbon emissions, and resource exploitation, leading to serious
environmental constraints. Also X. Zhang, T. Feng, S. Zhao, G. Yang, Q. Zhang, G. Qin, L. Liu,
X. Long, W. Sun, C. Gao, G. Li
A study conducted by the Institute of Environmental Policy
and Social Policy of the University of Hong Kong (ICP) has shown that there is a negative
relationship between the increase in urban population and environmental quality. This study
makes an important contribution to the in-depth study of how Green Transport affects
environmental sustainability in BRI economies. In addition, the study introduces a new Green
Transport Index using heterogeneity testing techniques to analyze the relationship between
ecological footprints and green transport. The results of the study suggest that green transport
should be promoted in BRI economies to ensure environmental safety, use resources efficiently,
reduce traffic congestion, improve air quality, and restore healthy lifestyles. As
recommendations, the study suggests that BRI countries develop laws to encourage the use of
environmentally friendly vehicles by freight carriers and passengers. In addition, governments
should actively support the transition from conventional vehicles to environmentally friendly
transport systems. The following chapters of the study follow the following order: first, the
theoretical framework explains how environmentally friendly vehicles can help to build a
sustainable ecosystem and reduce carbon emissions. The literature review section provides an
analytical overview of previously published works, while the methodology section describes the
data sources and model used in the study. This is followed by empirical results and their
discussion, followed by research conclusions and recommendations for further research.
Theoretical framework: As Papadis and Tsatsaronis (2020) point out, ensuring environmental
sustainability and reducing carbon dioxide (CO₂) emissions are among the most pressing global
challenges in the context of climate change. One of the ways to solve these problems is to use
green transport systems that include environmentally friendly vehicles. The theoretical
framework of this study is the “leapfrogging development theory”. This theory explores the
potential for achieving environmental sustainability and significantly reducing carbon emissions
through green transport systems. The study examines a broad range of technological advances,
behavioral changes, policy reforms, and their combined effects. According to the “leapfrogging
theory,” developing or underdeveloped countries can achieve development by directly adopting
advanced technologies and modern practices, without going through the complex and
environmentally harmful stages of industrial development. This theory is particularly important
in the context of the green economy, which argues that lagging countries can avoid the
3
X. Zhang, T. Feng, S. Zhao, G. Yang, Q. Zhang, G. Qin, L. Liu, X. Long, W. Sun, C. Gao, G. Li, Elucidating the impacts
of rapid urban expansion on air quality in the Yangtze River Delta, China, Sci. Total Environ. 799 (2021) 149426,
https://doi. org/10.1016/J.SCITOTENV.2021.149426
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environmental problems faced by developed countries by adopting advanced technologies. Thus,
these countries can achieve economic growth while also improving environmental quality by
introducing innovations such as digital infrastructure, renewable energy sources, and efficient
industrial practices. They can embark on a more sustainable development path by bypassing
energy- and resource-intensive, polluting phases. The study also examines the impact of foreign
direct investment (FDI) on pollutant emissions in countries that joined the “One Belt, One Road”
initiative before and after 2013. The study analyzes FDI investments in six areas: green transport,
technological progress, behavioral changes, infrastructure development, integrated planning, and
policy incentives. Previous studies have focused on developed countries, where the role of green
innovation in reducing emissions has been observed in the transition from stage B to stage C.
However, this study finds that FDI flows are being redirected from rich countries to less
developed countries within the framework of the “One Belt, One Road” initiative. As a result,
green transport systems are developed in these countries, and a specific change in pollution
levels is observed - a transition from stage A through B to stage C. This shows that there are
significant differences in the impact of green transport on environmental quality compared to
previous studies. The effective implementation of green transport systems requires technological
innovations that serve to reduce environmental impacts and reduce carbon emissions. In
particular, development is required in electric vehicle technology - battery efficiency, charging
stations and energy storage systems. Electric vehicles are considered an environmentally
acceptable alternative to traditional internal combustion engines due to their zero exhaust
emissions and reduced carbon footprint. At the same time, the use of biofuels and hydrogen fuels
is also promising for sustainable transport. In order to reduce carbon emissions, it is necessary to
encourage the transition from private cars to public transport. As part of this process, it is
envisaged to switch to the use of ecological means of transport, such as carpooling, cycling, and
walking instead of cars. Public transport systems equipped with smart technologies play an
important role in reducing traffic congestion and reducing CO₂ emissions. At the same time,
walking and cycling also serve to strengthen public health. Infrastructure investments that
promote environmental sustainability are important for the implementation of green transport.
For example, separate pedestrian and bicycle lanes, convenient public transport systems that are
interconnected encourage people to use environmentally friendly means of transport. It is also
necessary to establish charging networks for electric vehicles and connect these systems to
renewable energy sources. Green transport planning must consider the balance between land use,
urban sprawl and transport efficiency. Through the cooperation of city planners, legislators,
transport managers and other stakeholders, transport networks are being established that serve to
reduce CO₂ emissions. Intelligent transport systems, on the other hand, create opportunities for
real-time data collection, optimal routing and traffic management, reducing emissions and
increasing overall transport efficiency. Strict legislation and incentive mechanisms are needed to
popularize green transport, reduce CO₂ emissions and protect the environment. Strong pollution
control regulations, fuel efficiency standards and the promotion of renewable energy sources will
accelerate the transition to green transport. Tax incentives, subsidies and other financial support
should be provided to promote the use of electric vehicles and the development of charging
infrastructure. In addition, mixed-use land use, transport-oriented urban development, and
compact building policies reduce the number of private cars and promote the use of sustainable
transport.
3. Materials and Methods
3.1. Empirical Model. This study analyzes the relationship between environmental quality
(expressed in ecological footprint and CO2 emissions) and green transportation. This relationship
is studied in the context of renewable energy, institutional quality, innovation (measured by
patents), and urbanization factors, using the example of Belt and Road countries. The study
evaluates the impact of green transportation on BRI (Belt and Road Initiative) policies over the
period 1990–2021. To determine the impact of BRI, 2013 was selected as the main treatment
year, and then the analysis continued in 2014 and 2015. "Green transportation" was taken as the
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main independent variable. This concept includes investment and infrastructure development for
electric and low-carbon vehicles (trams, trains, buses and cars) (see Table 1). In accordance with
the research objectives, the following model is built in the form of a panel model:
lnEFit = αit + βlnGTPit + ξlnIQit + γlnINOit + θlnURBit + ϑlnREit + εit (1)Where:
i is the country in the panel,
t is the time period (1990–2021),
α is a constant value,
β, ξ, γ, θ, ϑ are coefficients for green transport, institutional quality, innovation, urbanization and
renewable energy,
εit is an error term.
3.2. Data and sources. The study used annual panel data covering the period 1990–2021. The
impact of green transport on the ecological footprint and CO2 emissions is analyzed using the
example of the Belt and Road countries. Data are taken from the following sources: the United
Nations Conference on Trade and Development (UNCTAD), World Development Indicators
(WDI), and the Global Footprint Network.
3.3. Econometric methodology. The study used difference-in-differences (DID) and DIDID
(Difference-in-Difference-in-Difference) methods. These methods are effective in assessing the
impact of policies in situations where there are variations over time and space, as well as
experimental and control groups. The DIDID model increases the reliability of the results by
introducing an additional dimension (e.g., time, treatment, region, or demographic group) to
address the endogeneity problem. The DIDID model allows for a clear isolation of the program
impact in the BRI participating countries.
The model is expressed as follows:
lnEFij = β0 + β1(Treati
⋅
Postt) + ηiControlsit + γt + λi + ϵit (2)Where:
lnEFij is the environmental quality (dependent variable),
Treati is an indicator of BRI membership (Treat = 1 – member; Treat = 0 – non-member),
Postt is the time when the policy came into effect (Post = 1 if time > September 2013, 0
otherwise),
Controlsit is the control variables (renewable energy, institutional quality, urbanization, patents),
γt, λi are time and country fixed effects.
The coefficient β1 represents the difference between BRI members and non-members after 2013.
In addition to this model, the following DIDID model was used: lnEFijk = β0 +
β1(Treati
⋅
Postt
⋅
lnGTPk) + ηiControlsit + γt + λi + ϵit (3) Here β1 represents the impact of
green transport development on environmental quality after 2013. For example, if β1 = 0.5, this
means that when green transport increases by one unit, environmental quality for BRI members
improves by 0.5 units. To ensure robustness, sub-sample regression analyses were also
conducted on the DID and DIDID models: Sub lnEFijk = β0 + β1(Treati
⋅
Postt
⋅
lnGTPk) +
ηiControlsit + γt + λi + ϵit (4) Here, "Sub" is the regression on selected subgroups.
3.4. Stability testing. Several stability tests were conducted to confirm the reliability of the model
results. Each of them checks the robustness of the main regression results through separate
methodological approaches:1. Parallel trend testing: An important condition of the DID
methodology is that the experimental and control groups have the same (or very similar) trends
before the policy is implemented. To check this, changes in the ecological footprint and CO2
emissions in the years before the policy is implemented are compared through graphical analysis
and formal tests.2. Placebo tests: Artificial (fake) treatment years are selected for the period
before the start of the BRI policy and their effects on environmental indicators are tested. If a
significant effect is not observed in these years, this indicates the presence of a real policy
effect.3. Neighborhood comparison: Differences between BRI members and their geographically
and economically similar neighboring countries that are not part of the BRI are studied. This
helps to determine whether the BRI impact is a policy outcome and not a result of other external
factors. 4. Other measures of variables: Regressions are rerun by replacing variables such as
green transport, innovation, and institutional quality with alternative (i.e., based on a different
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statistical source or calculation method) indicators. If the results do not change, this confirms
their robustness. 5. Sensitivity to public disclosures: Some countries may have a strong influence
on the results. The results are retested by removing such countries from the model. If the main
coefficients remain significant, the model is considered robust. The results of these tests show
that investment in green transport infrastructure under the BRI significantly improves
environmental quality. In particular, the ecological footprint is reduced and CO2 emissions are
reduced. The results are consistent across models, groups, and methodologies.
4. Empirical results and discussion
Table 2
Descriptive statistics
Variable
Average
value
Distribution
rate
Smallest(min) The
largest
(max.)
General
2.3829
1.0321
-0.4971
4.0716
InEF
Among
1.647
20.296
27.592
Countries
0.821
19.464
24.876
InGPT
Within
16.345
1.674
13.074
21.078
General
1.678
13.701
20.979
Among
0.195
14.182
17.271
Countries
− 0.733
1.043
− 8.849
1.693
InINO
Within
0.925
− 3.145
1.442
General
0.498
− 6.437
1.277
Among
4.384
0.314
3.040
5.053
InURB
Countries
0.271
3.402
4.806
Within
0.163
3.442
4.957
General
1.9657
0.8245
0.549
3.576
InCO2
Among
0.7947
0.733
3.217
Countries
0.3310
0.789
3.1383
InRE
Within
14.871
1.734
11.174
20.242
General
1.716
12.177
20.008
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This section presents the results of the main econometric analysis conducted under different
economic scenarios in the countries of the "One Belt, One Road" (BRI). First, we predict our
model representing the impact of green transport on the ecological footprint and carbon dioxide
emissions over time. In the final step, we check whether our findings are consistent with the
results of the main analysis.
Table 3
Correlation matrix
Table 4
Base model (years after 2013)
Table 5
Base model (years after 2014)
Variable
1
2
3
4
5
6
InEF
1,000
(0.000)
InGPT
0.648
1.000
(0.000)
InINO
0,358
0.067
1.000
(0.000)
(0.007)
InURB
0.093
-0.304
0.128
1.000
(0.000)
(0.000)
(0.000)
InCO2
0,698
0.968
0.056
-0.292
1.000
(0.000)
(0.000)
(0.023)
(0.000)
InRE
0.445
-0.357
0.402
0.487
-0.331
1.000
(0.000)
(0.000)
(0.000)
(0.000)
(0.000)
O’zgaruvchilar
InEF
InCO2
InEF
InCO2
Treat#post
-0.0938
0.0172
0.0553
0.122
(-1.009)
(0.186)
(1.301)
(3.278)
RE
1.026
1.006
(77.96)
(81.09)
InQI
-0.0881
-0.154
(-1.427)
(-2.640)
InURB
-0.0327
0.241
(-0.665)
(5.253)
InGPT
0.943
0.780
(47.75)
(31.09)
InINO
-0.0840
0.0462
(-6.229)
(3.684)
Doimiy qiymat
23.35
23.93
-0547
(53.61)
(59.66)
(-1.435)
(4.260)
Kuzatuvlar soni
2042
2042
2042
2042
Mamlakatlar
soni
66
66
66
66
Variables
InEF
InCO2
InEF
InCO2
Treat#post
-0.0867
0.0185
0.0622
0.125
(-0.851)
(0.181)
(1.437)
(3.184)
RE
1.023
1.005
(79.43)
(82.79)
InQI
-0.0867
-0.154
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Table 2 presents descriptive statistics. The standard deviations of the “within” and “between”
measures of the variables indicate the variability of the variables over time and across BRI
countries. As can be seen from Table 2, most variables have significant standard deviations in
the “between” and “within” differences. Table 3 presents the results of the correlation matrix.
Green transport is strongly correlated with the ecological footprint and CO₂. Table 4 presents the
regression results of the main model, with environmental quality (lnEF) and carbon dioxide
emissions (lnCO₂) as dependent variables, respectively. The models in the first and second
columns do not include control variables, while the models in the third and fourth columns
include control variables. The results in the first and second columns of Table 4 indicate that
control variables are necessary because environmental quality is influenced by many factors.
Without control variables, the Treat#Post parameters are −0.0938 (t = −1.009) and 0.0172 (t =
0.186), respectively, and are not statistically significant. However, when control variables are
included, the Treat#Post parameter in the third column is 0.0533 (t = 1.301), which is not
statistically significant, but the direction is consistent with the expected effect. The parameter in
the fourth column is 0.122 (t = 3.278), which is statistically significant, indicating that
environmental quality has improved in BRI member countries since 2013. To account for the
possibility of time lag in the DID analysis, the regression results for years after 2014 (Post =
Years > 2014) are presented in Table 5, confirming the results in Table 1.
Table 6
Main DIDID model (years after 2013)
(-1.404)
(-2.641)
InURB
-0.0370
0.238
(-0.755)
(5.197)
InGPT
0.941
0.777
(48.05)
(31.18)
InINO
-0.0835
0.0466
(-6.188)
(3.1717)
Constant value
23.40
23.97
-0.473
1.950
(53.76)
(59.77)
(-1.259)
(4.443)
Number
of
observations
2042
2042
2042
2042
Number
of
countries
66
66
66
66
Variables
InEFI
InCO2
InEFI
InCO2
Treat#post
InGTP
-0.0665
-0.109
0.0746
0.0486
(-1.243)
(-2.042)
(2.942)
(2.093)
RE
1.026
1.006
(78.51)
(80.60)
InQI
-0.0783
-0.154
(-1.281)
(-2.646)
InURB
-0.0227
0.250
(-0.461)
(5.382)
InINO
-0.0803
0.0472
(-5.970)
(3.754)
Constant Value
-1.969
-1.201
(-0.392)
1.838
(-1.097)
(-0.648)
(-0.604)
(2.229)
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BRI membership has had a significant positive impact on environmental quality compared to
non-member countries. This improvement is due to three main factors: 1. International
cooperation and exchange of experiences within the BRI have led to the formation of a common
understanding of green development, which has improved environmental outcomes. 2. The
integration of green innovations into the BRI has helped enterprises improve their production
technologies and reduce polluting emissions. 3. The financial support provided by the BRI has
helped modernize production technologies, thereby reducing their environmental footprint.
However, no significant results have been observed in the parameters of the LnEF model, which
is in contrast to the impact more clearly expressed in the LnCO₂ model. This difference may be
due to the statistical settings of the LnEF model and the fact that other factors are not taken into
account. The results of the DIDID (Difference-in-Difference) regression analysis are presented in
Table 6 (Post = Years > 2013) and Table 4 (Post = Years > 2014). In Table 6, the corresponding
coefficients for Treat#Post#lnGTP in models 3 and 4 are significant: 0.0746 (t = 2.942) and
0.0569 (t = 2.324). These results indicate that green transport significantly improves
environmental quality. There are two ways to reduce environmental damage and improve quality
under the BRI: 1. Countries that receive BRI investment will have financial resources to develop
green transport infrastructure, which will lead to reduced CO₂ emissions through electric vehicles,
pedestrians, and bicycle lanes. 2. BRI cooperation will enable the introduction of advanced green
transport technologies through technological spillover effects. This will reduce pollutant
emissions and contribute to a healthy ecosystem. The effectiveness of these routes depends on
the level of development of the recipient country. For less developed countries, the positive
regression parameters, for example, the values of 0.0746 (t = 2.942) and 0.0569 (t = 2.324) in
Models 3 and 4 in Table 7, indicate a technological leapfrogging process, rather than a negative
one, of green transport. In addition, to maximize the positive environmental impact of the BRI, it
is necessary to carefully plan and implement projects, take into account environmental factors,
and introduce transparent monitoring and evaluation systems. In summary, green transport
within the BRI will bring environmental benefits in two main directions: 1. Reduction of CO₂
emissions and improvement of environmental quality through the development of green transport
Observation
2042
2042
2042
2042
Number
of
Countries
66
66
66
66
Variables
InEFI
InCO2
InEFI
InCO2
Treat#post
InGTP
-0.0694
-0.103
0.0746
0.0569
(-1.199)
(-1.771)
(2.774)
(2.324)
RE
1.023
1.006
(79.90)
(82.38)
InQI
-0.0773
-0.155
(-1.263)
(-2.665)
InURB
-0.0283
0.251
(-0.576)
(5.419)
InINO
-0.0798
0.0486
(-5.929)
(3.861)
Constant value
-2.672
-1.664
-0.333
2.043
(-1.506)
(-0.906)
(-0.522)
(2.557)
Observation
2042
2042
2042
2042
Number
of
countries
66
66
66
66
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infrastructure at the expense of financial resources. 2. Reduction of polluting emissions and
improvement of environmental performance through the introduction of advanced technologies
at the expense of technological diffusion. The control variables (lnQI, lnURB, lnINO) play a
significant role in reducing CO₂ emissions and improving environmental quality. Although the
results for RE (renewable energy) are statistically positive, in practice this occurs through
technological leapfrogging in developing countries. Therefore, future research should focus on
refining statistical adjustments and further studying the environmental impact of BRI
membership.
4.2. Placebo tests
To strengthen the results, we repeated each DIDID (difference of differences) analysis 500 times,
in which the value of “Treat” was randomly assigned. If the regression results in Tables 6 and 7
were truly significant, then the results in these tables should be within the bounds of the 500
regression parameters. The results presented in Figures 3–5 show that Models 3 and 4 (in Table 3)
successfully passed the placebo test. The true regression parameters are within the bounds of the
500 randomly assigned regression results with “Treat”, indicating that these results are reliable.
Figure 3 plots the distribution of the 500
regression parameters using the SK kernel
method, with the true parameter indicated by
the red line.
Figure 1 Parallel trend test
6 Figures 1 and 7 confirm that models 3 and
4 in Table 7 pass the placebo test. The true
parameters are within the limits of the results
obtained for the randomly assigned “Treat”
values in 500 regressions, which indicates
the reliability of the conclusions. These
results indicate that the development of
green transportation and the country’s
participation in the BRI (One Belt, One Road) initiative are important in reducing CO2
emissions.
Figure 2 Placebo Trial (Model 3 in Table 6)
Figure 3 Placebo Trial (Model 4 in Table
6)
Figure 4 Placebo test (Model 3 in Table 7)
6- and the placebo test results for model 7 show that
the parameters in Table 7 are reliable. To further
ensure the reliability of the results, all countries were
divided into two groups using the median distance
clustering method based on carbon emissions (lnCO2)
and environmental quality (lnEF). There is a high
degree of similarity within these groups. DID and
DIDID analyses were then conducted, and the results
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are presented in Tables 8 and 9.
Figure 5 Placebo test (model 4 in Table 7)
8- and the results of Table 9 show a significant
positive trend in the cross term coefficients. This
means that green transport has an unexpected impact
on environmental quality after the inclusion of BRI.
However, this positive result should not be interpreted
as green transport worsening environmental quality.
On the contrary, it indicates that the transport
infrastructure in the host countries is developing
rapidly – that is, in a “leap” manner. The placebo test
results for Models 1, 2, 3 and 4 (in Table 9) once again confirm these conclusions.
Table 8 DID analyses
Table 9 DIDID analyses
Cluster 1
Cluster 2
Cluster 1
Cluster 2
Variables
InEF
InEF
InCO2
InCO2
Treat#post
0.0241
-0.0850
0.106
0.295
(0.700)
(-0.626)
(3.009)
(2.761)
RE
0.903
1.012
0.974
0.944
(51.20)
(45.95)
(53.37)
(51.96)
InQI
-0.159
0.0454
-0.274
-0.0642
(-2.533)
(0.419)
(-4.211)
(-0.690)
InURB
0.00785
-0.0141
0.366
0.0214
(0.145)
(-0.181)
(6.559)
(0.316)
InGTP
0.742
0.979
0.696
0.862
(33.34)
(32.73)
(25.24)
(28.41)
InINO
0.0231
-1.137
-0.0182
0.0392
(1.369)
(-6.056)
(-1.038)
(2.085)
Continuous
Indicators
3.168
-1.319
3.282
1.718
(6.877)
(-2.144)
(6.380)
(2.968)
Observations
1101
941
1101
941
Number
of
Countries
52
47
52
47
Cluster1
Cluster2
Cluster1
Cluster2
Variables
InEF
InEF
InCO2
InCO2
Treat#post
0.0681
0.311
0.0757
-0.0712
(3.228)
(2.006)
(3.477)
(-0.583)
RE
0.896
1.017
0.982
0.941
(51.03)
(45.89)
(53.21)
(51.96)
InQI
-0.131
0.0212
-0.259
-0.0819
(-2.113)
(0.190)
(-4.001)
(-0.875)
InURB
0.0361
-0.0314
0.370
0.0264
(-0.670)
(-0.395)
(6.565)
(0.391)
InINO
0.0293
-0.150
-0.0171
0.0380
(1.769)
(-6.410)
(-0.908)
(1.972)
Continuous
6.415
-2.960
5.345
-0.568
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One of the main results is that the coefficient on renewable energy consumption (RE) is -1.006 (t
= 82.38). This means that there is a positive, statistically significant relationship between the use
of renewable energy and the increase in pollution. That is, as countries start to pay more attention
to renewable energy, the level of pollution also increases. The second important finding is the
coefficient on institutional quality (lnQI) is -0.155 (t = -2.665), which indicates a negative
relationship. Countries with lower institutional quality tend to have higher pollution levels. The
coefficient on urbanization (lnURB) is also found to be -0.251 (t = 5.419). This suggests that
there is a positive relationship between urbanization and pollution: as the level of urbanization in
a country increases, pollution also increases. The coefficient on the number of patents (lnINO) is
0.046 (t = 3.684), which also indicates a positive and significant relationship. Countries with
more patents have higher pollution levels. Analysis of the control variables shows that reliance
on renewable energy, low institutional quality, urbanization level, and a large number of patents
lead to increased pollution. That is, countries with a low level of development, low institutional
quality, and high urbanization face more pollution. The relationship between the number of
patents and pollution also suggests that economic development (patent accumulation) can lead to
increased pollution. To strengthen the results, placebo tests were conducted on the four models in
Table 9. By randomly grouping the samples, models 1, 2, 3 and 4 were re-estimated 500 times
each. The kernel density distribution of the parameters was calculated and the true parameters
are shown as red lines in Figures 8, 9, 10 and 11 (Appendix 1). The placebo test results showed
that models 1, 2 and 3 passed the test, but model 4 failed the test. This proves the positiveness of
the parameters in Table 9. The presence of a sample of developed and developing countries
allows the study to have a deep analysis and helps to better understand the complex relationship
between the control variables and pollution. These observations strengthen the theoretical
framework and interpretation of the difference-in-differences (DID) model. The DID analysis
sheds light on the additional pollution caused by economic growth and the pollution levels
associated with growth constraints.
5. Conclusions and Policy Recommendations. In our empirical study, we have identified a
paradoxical and complex phenomenon regarding the impact of green transport within the Belt
and Road Initiative (BRI) member states. Our results show that there is an unexpected negative
relationship between the introduction of green transport and environmental quality in the context
of less developed countries within the BRI. This result contradicts existing theoretical views,
which generally associate the introduction of green transport systems with reduced carbon
dioxide (CO₂) emissions and improved environmental conditions. However, our study suggests
that this unusual phenomenon, when observed within the BRI, requires an alternative theoretical
framework that takes into account the specific dynamics.
6-chart Placebo test (model 1 in Table 7)
Chart 7 Placebo test (model 2 in Table 7)
indicators
(7.713)
(-2.988)
(5.497)
(-0.614)
Observations
1101
941
1101
941
Number
of
countries
52
47
52
47
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According to our proposed theoretical view, the reason for this contradictory result lies in the
complex process of green transport adoption and economic development in the less developed
BRI member countries that is taking place simultaneously. As these countries adopt green
transport strategies, their economic landscape undergoes significant changes, resulting in
increased CO₂ emissions. This complex interplay suggests that the positive environmental
impacts of green transport are offset by the negative environmental impacts of rapid economic
growth—which opens up a unique and new development path. The concept of “leapfrogging”
(development by bypassing intermediate stages) is central to our proposed theoretical framework.
This approach explains the development path of the less developed BRI countries. They jump to
previously developed stages rather than passing through the traditional stages. This process
causes the positive environmental impact of green transport to be overshadowed by the rate of
economic growth, thus creating a situation that contradicts classical theories.
Figure 8 Placebo test (Model 3 in Table 7) Figure
10 Placebo test (Model 4 in Table 7).
Also, the wealth disparity among the BRI members plays an important role. The cooperative and
supportive nature of this initiative leads to the investment of rich member states in their poorer
partners and the transfer of advanced technologies. Thanks to this cooperation, less developed
countries quickly move towards industrialized societies, bypassing the intermediate stages. This
process is a unique path that reveals the relationship between wealth disparity, leapfrogging, and
the environmental consequences of green transport. In conclusion, our study reveals a
multifaceted contradiction in the environmental consequences of green transport in the BRI
countries. The theoretical framework we propose, based on leapfrogging development and
wealth disparity, serves to explain the observed discrepancies. This new development path is a
stark departure from the traditional paradigm and requires a deeper understanding of the
environmental implications of green transport initiatives in collaborative organizations like the
BRI. Our research broadens the scope of ecological analysis by illuminating the complex
interactions between transport systems, economic development, and wealth inequality.
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