Assessing the spillover effects of research and development and renewable energy on CO(2) emissions: international evidence

The primary motivation of this paper is the lack of consensus on the impact of renewable energy (RE) and research and development (R&D) expenditure on CO(2 )emissions in the literature. Current literature has mostly ignored the spillover effect of R&D on CO(2 )emissions by increasing the intensity effect of technology, leading to biased results. Further, little is known about the impact of previous epidemics on CO(2 )emissions. This study fills these gaps by evaluating the spillover effects of RE and R&D on CO(2 )emissions in a global panel of 54 countries from 2003 to 2017. Using a two-way time- and spatial-fixed-effects panel analysis, we find both income-induced and scale effects of economic growth are present in our panel, though the scale effect is the dominant one. Our findings indicate that economic growth increases CO(2 )emissions at a decreasing rate, validating the Environmental Kuznets Curve hypothesis, and that urbanization and foreign trade worsen the environment. We also find that epidemic episodes before COVID-19 had a nonsignificant impact on CO(2 )emissions internationally. More importantly, our results confirm the presence of both the intensity and scale effects of R&D, with the intensity effect being the dominant one. We find overwhelming evidence that global R&D investment led to an overall (direct plus spillover) reduction of CO(2 )emissions, driven by its spillover effect, through two channels: RE and economic growth. Finally, we find that RE installations assist with reducing CO(2 )emissions internationally, though RE composition and state of R&D can lead to different findings. Our findings have significant policy implications for sustainable development. Our RE and R&D-spillover results support the policy recommendation of shifting to high-tech clean energy sources

The Circular Economy

When production resources are considered significant economic variables, the circular economy (CE) is viewed as a closed-loop economic system. It is a sustainable development strategy based on limited resources that addresses urgent problems of environmental degradation and resource scarcity and depletion. This study gives the definitions of such a strategy by thoroughly reviewing the growing research literature on the subject. Additionally, the paper reviews the rapidly growing body of literature on CE, examining its concepts and current practices and evaluating its implementation. Comparing the CE concept with the current linear economy of obtaining materials; producing, distributing, and consuming goods; and discarding waste reveals why a shift to regenerative sustainable industrial development with a closed-loop is necessary. It also compares CE with concepts like the Green Supply Chain Management in an effort to better understand their constituent dimensions. Additionally, while expressing the difficulties inherent in developing such a strategy, the paper examines the prospects and impediments to its development

Environmental effects of entrepreneurship indices on ecological footprint of croplands and grazing lands in the economy

When production resources are considered significant economic variables, the circular economy (CE) is viewed as a closed-loop economic system. It is a sustainable development strategy based on limited resources that addresses urgent problems of environmental degradation and resource scarcity and depletion. This study gives the definitions of such a strategy by thoroughly reviewing the growing research literature on the subject. Additionally, the paper reviews the rapidly growing body of literature on CE, examining its concepts and current practices and evaluating its implementation. Comparing the CE concept with the current linear economy of obtaining materials; producing, distributing, and consuming goods; and discarding waste reveals why a shift to regenerative sustainable industrial development with a closed-loop is necessary. It also compares CE with concepts like the Green Supply Chain Management in an effort to better understand their constituent dimensions. Additionally, while expressing the difficulties inherent in developing such a strategy, the paper examines the prospects and impediments to its development

Regional and spatial impacts of external and internal conflicts on ecological footprint: the case of Middle East and Africa

The economic and environmental structures of countries are greatly impacted by domestic and foreign conflicts. To promote sustainable development, it is crucial to understand the spatial impact of these conflicts on the ecological footprint of a region. With a focus on Middle Eastern and African countries, this paper investigates the impact of such conflicts on their environments, taking into consideration the unique spatial features of their ecological footprints. Using a spatial econometric model, the study assesses the contributions of ecological footprint determinants, particularly internal and external conflict indicators, across 46 Middle Eastern and African countries from 2001 to 2019. The results indicate that internal conflict can lead to increased pressure on natural resources and ecological systems in neighboring countries, while energy use and economic growth impose a significant ecological burden both domestically and abroad. While urbanization and resource rents were found to reduce the ecological footprint, trade openness was found to be nonsignificant. Conflicts such as war, foreign pressure, civil war, and civil disorder were found to have a significant negative impact on the environment, suggesting that reducing these conflicts would improve environmental circumstances. The findings highlight the need for conflict resolution measures to achieve a sustainable environment in the Middle Eastern and African regions and have implications for other countries facing similar issues

Assessing the environmental efficiency of OECD countries through the lens of ecological footprint indices

Environmental efficiency plays a crucial role in achieving sustainable economic development. This study aims to enhance the current understanding of dynamic environmental efficiency by using Data Envelopment Analysis (DEA) in conjunction with the ecological footprint index. This study evaluates 27 OECD countries' environmental performance from 2000 to 2017, employing net capital stock, labor force, and energy consumption as inputs, ecological footprint as undesirable output, and GDP as desirable output. We utilize 16 window Slack-Based Measurement DEA (SBM-DEA) models, each representing consecutive years within the observation period. Additionally, we adopt the Global Malmquist-Luenberger Index (GMLI) techniques to facilitate a simultaneous evaluation of the efficiency levels for each country. Our findings reveal that the United Kingdom and Lithuania were the most and least ecologically efficient countries among the 27 OECD countries, respectively. Over the 18-year observation period, all countries showed both progress and setbacks in environmental efficiency, with a modest overall improvement. Poland, Denmark, Slovakia, and Lithuania were the most improved countries in environmental performance, while Canada and Japan showed the most significant regressions in environmental efficiency. We highlight the need for policymakers to prioritize sustainable economic growth and consider ecological footprints when making economic decisions to enhance environmental efficiency in OECD countries. Our findings have can guide policymakers in designing effective policies and strategies to enhance environmental efficiency and promote sustainable economic development

Exploring non-linear causal nexus between economic growth and energy consumption across various R&D regimes: cross-country evidence from a PSTR model

Purpose: This study endeavors to elucidate the divergent conclusions encountered in empirical research regarding the interplay of Economic Growth (EG) and Energy Consumption (EC). Design/methodology/approach: For this purpose, we employ the Panel Smooth Threshold Regression (PSTR) model to intricately examine the non-linear impacts of independent variables on EC and EG within a dataset encompassing 46 countries over the period from 1996 to 2021. Findings: The outcomes of our investigation can be summarized as follows: First, the findings underscore the positive impact of the logarithm of net capital formation on EG. This impact is particularly pronounced at low levels of Research and Development (R&D), gradually waning beyond a certain threshold. Second, the ratio of capital to labor exhibits a negative influence on EC at lower R&D levels. Notably, these detrimental impacts become more pronounced as R&D levels increase. Third, trade openness contributes positively to EG, particularly evident at low R&D levels. However, with increasing R&D levels, the incremental benefits from trade diminish. Finally, our findings lend support to the feedback hypothesis. Nevertheless, the impact of R&D expenditures in countries moderates these positive effects. Practical implications: Policymakers should strategically balance resource allocation between capital formation and research endeavors, considering diminishing returns at elevated levels of R&D spending, to ensure sustained EG

Source identification and ecological risk assessment of polycyclic aromatic hydrocarbons in surface sediments (Case study: Pars special economic energy zone)

Background and purpose: Polycyclic aromatic hydrocarbons (PAH) compounds are amongst the most hazardous environmental pollutants due to some features such as chemical stability, low degradation, bioaccumulation, and high toxicity for living organisms. Their resources are found in Persian Gulf beaches, so, this study aimed at investigating the concentration, source identification, and ecological risk of PAH compounds in coastal sediments in Pars Special Economic Energy Zone (PSEEZ), Iran. Materials and methods: In order to assess the concentration of PAHs, 16 stations along the coast were selected and in each station two samples were collected. After preparation and extraction of samples using Soxhlet, the concentrations of these compounds were determined by HPLC. The toxicity evaluation indicators and diagnostic ratios were used to assess the ecological risk and determining their origin. Results: Mean concentration of PAHs in sediment was 292.72±54.44 ng/g dry weight. The mean effects range-median quotient of the PAHs (M-ERM-Q, M-PEL-Q), toxic equivalence quotient (TEQ), and mutagenic equivalence quotient (MEQ) showed that current values were less than the permissible limit. Comparison of PAHs concentration with sediment quality standards (NOAA, SQGs, and EPA) showed that the values for all compounds were lower than the standard limits (PEC, TEC, PEL, TEL, ERM). However, among these compounds, the average concentration of Acl was higher than the ERL standard and the concentrations of Acl, Ace, and Phe were higher than the EPA toxicity threshold. Conclusion: In this study, moderate PHAs pollution was seen in the region. Both petrogenic and fuel sources were found to be involved in introduction of these compounds into coastal sediments depending on the location of the station and its sources of contamination. Also, in terms of ecological risk, these compounds have low risks for living organisms. © 2018, Mazandaran University of Medical Sciences. All rights reserved

Does high-dose metformin cause lactic acidosis in type 2 diabetic patients after CABG surgery? A double blind randomized clinical trial

Metformin is a dimethyl biguanide oral anti-hyperglycemic agent. Lactic acidosis due to metformin is a fatal metabolic condition that limits its use in patients in poor clinical condition, consequently reducing the number of patients who benefit from this medication. In a double blind randomized clinical trial, we investigated 200 type 2 diabetic patients after coronary artery bypass surgery in the open heart ICU of the Mazandaran Heart Center, and randomly assigned them to equal intervention and control groups. The intervention group received regular insulin infusion along with 2 metformin 500 mg tablets every twelve hours, while the control group received only intravenous insulin with 2 placebo tablets every twelve hours. Lactate level, pH, base excess, blood glucose and serum creatinine were measured over five 12 h periods, with data averaged for each period. The primary outcome in this study was high lactate levels. Comparison between the 2 groups was made by independent Student’s t-test. To compare changes in multiple measures in each group and analysis of group interaction, a repeated measurement ANOVA test was used

Exploring the impact of entrepreneurial indicators on CO2 emissions within the environmental Kuznets curve framework: a cross-sectional study

Many countries emphasize entrepreneurship promotion as a policy focus. However, empirical research has often neglected the complex environmental consequences associated with such initiatives. In this study, we analyzed data using a panel model from 14 countries, covering the years 2002 to 2018. Our goal was to thoroughly assess the impact of eleven distinct entrepreneurship indicators on CO2 emissions. Our findings indicate that some control variables, like trade liberalization, are fundamental in reducing emissions. This contrasts with traditional views, which typically revolve around a consistent Kuznets curve that depicts the environmental effects of economic growth. Instead, our research uncovers a dynamic pattern transitioning from a concave upward trajectory to an inverted U-shaped curve, primarily due to increased levels of entrepreneurship. Remarkably, various entrepreneurial indicators, such as government support and policies, taxes and bureaucracy, governmental programs, and cultural and social norms, demonstrate direct positive impacts on CO2 emissions. Conversely, other indicators show a mix of positive and negative effects. Furthermore, examining the spill-over effects of entrepreneurship indicators, particularly in their role in energy use intensity and GDP per capita, reveals significant implications for improving energy consumption efficiency. However, it is important to acknowledge that despite the potential for enhanced efficiency, the negative effects resulting from an increased scale of output may not be completely counteracted

Vehicle miles traveled induced demand, rebound effect, and price and income elasticities: a US spatial econometric analysis

The economic literature on transportation is extensive, with travel demand being a well-studied topic. However, research on light-duty vehicle travel has not fully explored spatial dependencies arising from neighboring regions' driving activities. This study uses state-level panel data from 2000 to 2019 to examine U.S. vehicle miles traveled (VMT), focusing on spatial spillover effects through a Spatial Durbin Model. Our results reveal significant spatial interactions between states. Increased VMT in one state leads to spillover effects, increasing VMT in neighboring states. We present our findings as marginal effects, distinguishing between direct and indirect impacts. The direct price elasticity is estimated at −0.257, with a positive spillover impact of 0.036, yielding a total elasticity of −0.221. Induced travel exhibits a larger indirect effect than a direct effect, resulting in an overall impact of 0.276. Additionally, direct and total income elasticities are 0.194 and 0.146, respectively, while direct and total fuel economy rebound effects are 0.546 and 0.496, respectively. Moreover, higher numbers of licensed drivers, registered vehicles, and urbanization significantly influence a state's VMT. This research highlights the importance of regional planning among states, especially considering transportation infrastructure and environmental concerns related to driving and vehicle emissions