نقش فناوری اطلاعات و ارتباطات و درآمد سرانه بر انتشار CO2 در کشورهای صادرکننده نفت اوپک پلاس با تاکید بر منحنی زیست محیطی کوزنتس

Abstract
Nowadays, the world has seen tremendous progress in the penetration of information and communication technology in individual and social life in countries worldwide, regardless of income level. While the increasing penetration of information and communication technology in economic, social, and energy dimensions creates exciting challenges and opportunities, examining its role in reducing or increasing CO2 emissions is essential. Therefore, the main goal of this research is to investigate the role of information and communication technology on the environmental quality of selected oil-exporting countries. The difference between this research and previous studies is that to investigate the impact of ICT on CO2 emissions, it uses a composite index of information and communication technology based on the principal component method (PCA), unlike previous studies that used only one dimension (for example, the Internet penetration rate). In addition to investigating the relationship between ICT and the environment, the study examines the existence of the Kuznets environmental curve and the relationship between foreign trade and the carbon dioxide index. The model estimation of the effect of information and communication technology on the environmental quality of selected oil-exporting countries, including Iran, from 2009 to 2019 has been carried out using the generalized method of moments. The estimation results indicate an inverse U relationship between information and communication technology and carbon dioxide emissions. Also, the results confirm the Kuznets curve hypothesis in the studied countries. According to the study, foreign trade has a positive and significant impact on CO2 emissions.

Introduction
After introducing information and communication technology in recent decades, investigating the effect of information and communication technology on the environment has become one of the favorite subjects of economists in most countries. Today, the world faces several major environmental crises, some of which seem irreversible. Identifying the factors that can aggravate or reduce these environmental damages is necessary to save the planet and humankind from the consequences of these crises. The impact of information and communication technology (ICT) on the environment is a complex and controversial issue. ICT can have positive and negative effects on the environment. ICT tools and devices can be used to improve energy efficiency, which reduces CO2 emissions. However, many ICT devices contain non-renewable and non-recyclable components that can cause significant environmental damage.
The first big wave of public concern for environmental problems arose mainly from pollution caused by industrialization in advanced economies. In the late 1970s, environmental concerns began to be included in trade analyses, and the 1980s, they were considered essential topics in international negotiations (Jayadevappa et al., 2000). On the other hand, the possibility of an inverted U relationship between per capita income and environmental pollution has received much attention in recent years. Additionally, trade liberalization can effectively reduce environmental impact by increasing productivity in production, according to the principle of comparative advantage of countries in producing goods in which they have a comparative advantage (Cole, 2004).

Trade openness can cause CO2 emissions to increase and decrease simultaneously through economic growth and technological effect. Many studies show that economic growth often contributes to the destruction of the environment (Bekun et al., 2019; Song, 2021). It means that during the initial stages of a country's economic development, environmental destruction increases, but after reaching a certain level of industrialization, it gradually subsides at the turning point. In the context of developing countries, policymakers must optimize the trade-off between economic growth and environmental protection. Globalization has been an essential supporter of trade openness for emerging economies. From a theoretical perspective, trade openness has three broad implications for pollution—scale effect, combination effect, and technology effect (Antweiler et al., 2001). The scale effect shows that the increase in trade leads to an increase in energy consumption, which in turn causes an increase in environmental destruction. The combination effect revolves around the assumption that the inherent relative advantages of a country determine its production mix for the spread of user or capital-intensive industries. Finally, the technology effect states that increased trade facilitates better technology transfer among trading partners, leading to the adoption of cleaner and more efficient practices.
The impact of international trade on CO2 emissions has recently attracted much attention. Indeed, there has long been concern that countries may reduce emissions through international trade only to offset those reductions with increases elsewhere (a phenomenon sometimes referred to as carbon leakage).
Considering global warming and its dangers for current and future generations, we aim to investigate the role of information and communication technology as an influential factor in the quality of the environment of selected oil-exporting countries. Compared to previous studies, the innovation of this study is that we investigate the impact of ICT on CO2 emissions using a composite index of information and communication technology obtained from the principal component method (PCA).
The article's structure in this review is as follows: after introducing the theoretical literature and the background of the research, we give the research model and introduce its variables. Then, we provide a data description before estimation. After interpreting the results, we summarize and present a policy strategy.

Methodology
In this study, we investigate the impact of the Information and Communication Technology (ICT) index on carbon dioxide emissions for selected oil-exporting countries from 2009 to 2019, using the maximum available data and a consolidated data method. In our research, the model was derived from a study by Higón et al. (2017). In this study, the variables are carbon dioxide emissions (dependent variable), the ICT index (explanatory variable calculated using the PCA method), and control variables based on the summary of studies that have been carried out on the selected countries. The statistical sources used in the study are data banks such as the World Bank and the World Development Index (WDI).

Conclusion
The present study utilizes the generalized method of moments to investigate the correlation between the information and communication technology (ICT) index and carbon dioxide (CO2) emissions as an indicator of environmental pollution, with a particular focus on the Kuznets environmental curve in selected oil-exporting countries during the 2009-2019 period. A data description was presented before conducting the model estimation and related tests. The analysis reveals that Bahrain, the United Arab Emirates, Kuwait, and Saudi Arabia had more extended survey periods than others. However, in 2019, Iran ranked eighth in terms of the pace of technology development after Malaysia. Kuwait, Bahrain, and the UAE were the top three countries in terms of CO2 emissions. The average per capita income of the UAE, Brunei, Kuwait, Saudi Arabia, and Oman exceeded the panel's average. Regarding foreign trade, Iran is ranked nineteenth out of twenty countries under review, coming before Nigeria.
The study employs Pesaran's (2003) dependence test to address cross-sectional dependence in the data. Pesaran's unit root test (2007) was used to verify the mean stationarity of the variables. The co-integration of the variables was investigated using Pedroni's (1999) and Kao's (1999) co-integration tests to avoid spurious regression. The generalized method of moments was then employed to estimate the research model derived from theoretical foundations and previous studies. The results confirm the existence of a non-linear relationship between the ICT index and CO2 emissions in oil-exporting countries. The inverted U-shaped relationship between the ICT index and per capita CO2 emissions is verified, suggesting that an increase in the ICT index initially causes a rise in CO2 emissions. However, the emissions begin to decrease after reaching the threshold point of around 70.332 (calculated from the derivative of the dependent variable concerning ICT). Approximately 25% of countries have yet to reach the threshold level, and the expansion and development of ICT are expected to increase pollution. Conversely, the other countries including Iran, have exceeded the threshold value, and the expansion of ICT is expected to help reduce CO2 emissions.
Furthermore, the study confirms the inverted U-shaped relationship between per capita production and per capita CO2 emissions, indicating that increased per capita production initially leads to increased CO2 emissions per capita. However, after reaching the average annual threshold of about 42.27 thousand dollars, the emissions start to decrease. With the panel average per capita income of 14.239 thousand dollars and a median of 9.630 thousand dollars, almost all of countries except Saudi Arabia, have not yet to reach the threshold level. Thus, policies that promote increased production without environmental considerations may result in increased pollution and per capita CO2 emissions unless the threshold level is reduced to less than this value through complementary policies. Allocating increased per capita production to the environmental sector and investing in its infrastructure can reduce pollution costs.
Finally, the study confirms the positive and significant relationship between foreign trade and pollution, supporting the hypothesis of pollution havens in the countries under investigation.