Urbanization, industrialization and SO2 emissions in China: does the innovation ability of cities matter for air quality?

This paper aims to detail the relationships between urbanization, industrialization, the innovation ability of cities and local air quality in 284 cities in China using annual data. For the empirical outputs, the panel quantile regression analysis, which considers the heterogeneous nature of the data set, is employed. Initial findings indicate that (i) urbanization and industrialization negatively affect local air quality. (ii) Innovation capability of cities has a direct and improving impact on local air quality. Then, the paper estimates the moderating role of cities' ability to innovate in the polluting effect of urbanization and industrialization on local air quality. Remarkably, empirical evidence indicates that (iii) the innovation ability of cities also moderates the polluting impact of urbanization and industrialization on local air pollution. Based on the findings, the paper confirms the importance of both direct and moderator effects of the innovative environment in cities in tackling air pollution.

Greenhouse gas emissions, economic globalization, and health expenditures nexus: does population aging matter in emerging market economies?

Papers on population aging and the effects of environmental quality on health expenditure have critical policy consequences. However, findings in the relevant literature are mixed, and papers generally focus on developed countries. To provide new information to the literature, this paper examines the impact of globalization, economic growth, greenhouse gas emissions, and population aging on health expenditures in emerging market economies with annual data for the period 2000 to 2018. The paper follows a second-generation advanced panel data method that considers cross-sectional dependency. The estimation results reveal that population aging, economic growth, and greenhouse gas emissions have an increasing effect on health expenditures, while globalization has a decreasing effect. Furthermore, one-way causality running from population aging to health expenditures is confirmed, while a feedback causality relationship is observed between health expenditures and other indicators (globalization, economic growth, and greenhouse gas emissions). After all, the outputs of this paper can provide critical policy implications about the relationships between aging, globalization, air quality, and health expenditures in developing countries.

Dynamics and Co-movements Between the COVID-19 Outbreak and the Stock Market in Latin American Countries: An Evaluation Based on the Wavelet-Partial Wavelet Coherence Model.

The COVID-19 outbreak and the global uncertainty it causes produce an apparent panic in stock markets. Efforts to explain the economic spillover effects of COVID-19 can guide authorities to design a control policy against the financial impacts of pandemics. The paper examines the effects of the COVID-19 cases on the stock markets in the emerging Latin American countries of Argentina, Brazil, Chile, Colombia, Mexico, and Peru. The paper employs a continuous partial wavelet methodology to observe lead-lag relations between the daily variables of new COVID-19 cases and the stock market index for each Latin American country. Brazilian new COVID-19 cases led the Bovespa (BVSP) index to decline during the whole period, except February and June 2020, at one month-two month-frequency band. The wavelet and phase difference analyses indicate that, except for Brazil, COVID-19 cases did not affect the stock market indexes adversely during the whole sample period but did affect the stock exchange markets negatively during some sub-sample periods of the entire sample of each country. Dynamics of Latin American stock exchange markets in the short and long run can be explained by some other parameters of real and financial sectors and COVID-19 cases.

Dynamic correlations and portfolio implications across stock and commodity markets before and during the COVID-19 era: A key role of gold.

Novel Coronavirus (COVID-19) has affected stock markets around the globe, adding serious challenges to asset allocations and hedging strategies. This investigation analyses the dynamic correlations and portfolio implications among the S&P 500 index and various commodities (gold, WTI crude oil, Brent oil, beverages, and wheat) before and during the COVID-19 era. Using multivariate asymmetric GARCH models, the results show weak correlations during the standard period. However, the correlations intensify and become more complicated during the COVID-19 era, especially between gold and S&P 500. Similarly, bidirectional return and volatility spillovers across stock-commodity markets are more pronounced during the COVID-19 outbreak. Analysis involving the optimal portfolio weights and time-varying hedge ratios indicates that a $1long position in the S&P 500 can be hedged for 15 cents in crude oil during the standard period and for 33 cents in gold during the COVID-19 era. A portfolio of S&P 500 - beverages displays the highest VaR, while a portfolio of S&P 500 - gold displays the lowest VaR, especially during the COVID-19 era. This finding suggests that gold offers better portfolio diversification benefits and downside risk reductions, which are useful in determining strategies for portfolio investors during the COVID-19 outbreak.

The nexus between access to energy, poverty reduction and PM2.5 in Sub-Saharan Africa: New evidence from the generalized method of moments estimators.

Poverty reduction and environmental quality are the two main agendas of sustainable development goals. However, recent research suggests that there may be a dilemma between efforts to achieve these two goals. This paper aims to explore the existence of a dilemma between poverty and air pollution (PM2.5) in Sub-Saharan African countries using dynamic estimation methods. We also try to reveal the socio-economic dynamics that affect poverty and air pollution. Our findings are evaluated in four ways. First, there is strong evidence of a trade-off between poverty and PM2.5 emissions in African countries. Second, while economic growth and access to energy reduce poverty, they increase air pollution and thus confirm the dilemma. Third, population and trade do not significantly affect poverty, while population increases air pollution and trade decreases it. Fourth, and most notably, human development, property rights and economic freedom reduce both poverty and air pollution. Ultimately, this research supports the poverty-environment dilemma and provides empirical evidence for a solution.

The resilience of green firms in the twirl of COVID-19: Evidence from S&P500 Carbon Efficiency Index with a Fourier approach.

This paper investigates the resilience of environmentally friendly companies in an overwhelming economic and social environment that has been generated after the outbreak of the novel coronavirus disease (COVID-19) pandemic. To this respect, we have investigated the cointegration between the Standard & Poor's (S&P) 500 Carbon Efficiency Index (CEI) with COVID-19 cases, supplemented with covariates such as government response stringency to the pandemic, economic policy uncertainty, oil prices and global markets fluctuations. We have used daily data from 2nd January to 5th October 2020 and have employed a robust estimator within a Fourier approach to accommodate both sharp and smooth breaks. Our results suggest that green companies have been positively affected by the outbreak of COVID-19. Our paper provides practical implications for companies that wish to furnish themselves with resilience during rough times and stakeholders who wish to invest in safe, long-lasting returns.

Is gold favourable than bitcoin during the COVID-19 outbreak? Comparative analysis through wavelet approach.

The novel coronavirus (COVID-19) has tremendously oscillated the global financial markets. Consequently, investors feel pressured to find safe-haven investments during the pandemic crisis. Numerous studies have evaluated bitcoin's safe-haven properties during the COVID-19; however, the present study considered gold as a potential safe-haven for investors of renowned stock markets of Asia, Europe, and the US. The present investigation computed the ratio of gold to bitcoin (Gold_Bitcoin) and compared the safe-haven properties of gold in contrast to bitcoin. The present study analysed the Morlet Wavelet approach and found that most of the time during the COVID-19, gold investments proved to be more beneficial than bitcoin. Remarkably, the findings highlighted that the Gold_Bitcoin ratio increased in higher and lower frequencies combined with CAC40. In the long run, the return on investments in gold increased in contrast to bitcoin returns pooled with DAX30. Also, the Gold_Bitcoin ratio of the US stock market increased during the one-week and one-month cycles of January and August. Likewise, the Hang Seng Index caused the Gold_Bitcoin ratio to rise at a much higher frequency (i.e., the second half of January, the first half of February and April, and the first half of June and August), whereas IBEX35 surged Gold_Bitcoin at a lower frequency (i.e., during January, February, and August). In higher frequency bands, LSE increased the Gold_Bitcoin ratio (i.e., in February and March); nevertheless, Gold_Bitcoin showed a positive connection with FTSEMIB in the one-to-two month's frequency band (i.e., throughout January, February, and August). Interestingly, the returns on the Gold_Bitcoin ratio increased in the SSEC stock market in the high-frequency band (i.e., during March, May, and July 2020).

COVID-19 and Spillover Effect of Global Economic Crisis on the United States' Financial Stability.

Due to the novel coronavirus pandemic (COVID-19), the lockdown engendered has had a vicious impact on the global economy. This analysis' prime intention is to evaluate the impact of the United States' economic and health crisis as a result of COVID-19 on its financial stability. Additionally, the investigation analyzed the spillover impact of the worldwide economic slowdown experienced by COVID-19 on the United States' financial volatility. The study applied an autoregressive distributed lag (ARDL) model and discovered that the economic and health crises that occurred in the United States portentously upset the future expectations of its investors. Conspicuously, the health crisis in Spain and Italy were ominous spillovers of the United States' financial instability in the short-run. Likewise, an economic crisis ensued in the United Kingdom because of COVID-19 causing spillover for the United States markets' financial instability. The examination evaluated that Asian and African nations' economic crises perilously affects the United States' financial stability. The study determined that financial instability occurred in the United States due to its own economic and health crises persisted for a longer period than financial disequilibrium that occurred in other nations. The analysis suggested some strategies of smart lockdown that the government of the United States and other nations should follow to restart the economic cycle through tighter controls to minimize losses by following the steps of (a) preparing a lockdown checklist, (b) monitoring completion of lockdown tasks, and (c) complete a close-down stock take or count.

COVID-19 outbreak, lockdown, and air quality: fresh insights from New York City.

The outbreak of the COVID-19 pandemic has adversely affected all aspects of life and poses a severe threat to human health and economic development. New York City administration enacted a strict isolation decision at the end of March 2020 to tackle the COVID-19, creating a unique opportunity to assess air quality. Therefore, we investigated the impact of the lockdown on air quality in New York City. We evaluated the air pollutants concentration, i.e., PM2.5, CO, NO2, SO2, and O3, during the lockdown and compared them with pre-COVID-19. We explored the first phase of lockdown through a spatial approach, then formulated the air quality index (AQI) of each pollutant before and during the lockdown. Our findings revealed that (1) there was a significant decline in the concentration level of PM2.5 from 10.3 to 4.0 µg/m3 during phase one of lockdown. (2) NO2 concentrations have been decreased by up to 52% in 1st phase of lockdown. (3) O3 concentration has been increased by 44.4%. (4) Brooklyn, Manhattan, Queens, and Staten Island County encountered 18.75%, 55.62%, 47.14%, and 47% diminution in AQI due to lockdown as compared to 2018, respectively. Our key findings can provide critical environmental implications for policymakers, researchers, academics, and the US government.

Environmental efficiency of disaggregated energy R&D expenditures in OECD: a bootstrap DEA approach.

Two essential topics of Sustainable Development Goals (SDGs) are accessible which are clean energy (SDG-7) and climate change action (SDG-13). Developments and innovations in energy technologies play an essential role in achieving these goals. Therefore, any country should use energy R&D expenditures, which are the primary source of energy innovation, most optimally. This paper aims to investigate the environmental efficiency of R&D expenditures for energy efficiency, renewable energy, hydro and fuel cells, fossil energy, nuclear energy, and other power and storage technologies in OECD countries using data envelopment analysis (DEA) and bootstrap DEA. Estimation findings indicate that only the USA ensures the environmental efficiency in energy R&D expenditures among OECD countries. Although Japan, Canada, France, Germany, and Italy cannot provide environmental efficiency in energy R&D, their scores are very close to the efficiency frontier. Portugal, Hungary, and Slovak Republic are the countries with the lowest environmental efficiency in energy R&D expenditures. At the end of the investigation, this paper also provides an empirical estimation of the extent to which inefficient countries should change their R&D spending to achieve efficiency.

The nexus between tourism, economic growth, renewable energy consumption, and carbon dioxide emissions: contemporary evidence from OECD countries.

The relationship between tourism development, economic growth, renewable energy consumption, and carbon dioxide emissions has been examined in a variety of contexts; however, the extant studies report contradictory findings mainly due to utilizing arbitrary empirical techniques. We present a comprehensive literature review and the effects of tourism development, economic growth, and renewable energy consumption on the carbon dioxide (CO2) emission. Specifically, the effects of gross domestic product, renewable energy consumption, and tourism receipts on carbon dioxide emissions in OECD countries are examined utilizing the bootstrap panel cointegration technique and the augmented mean group estimator. The results showed that tourism development has negative and significant effects on CO2 emission in Canada, Czechia, and Turkey, while tourism development has positive and significant effects on CO2 emission in Italy, Luxembourg, and the Slovak Republic. Also, Belgium, France, New Zealand, and the Slovak Republic have shifted towards sustainable tourism practices. Theoretical and practical implications are discussed.

Towards sustainable development in China: do political rights and civil liberties matter for environmental quality?

China is a rising power of the twenty-first century with its brilliant economic performance as a result of the transition to the free market economy model. However, China's economic development process has caused high environmental costs. For the past decade, China has been the leading country responsible for global carbon dioxide emissions (CO2). Therefore, determining the dynamics that have a reducing effect on CO2 emissions in China is very important for the development of sustainable environmental policies. This paper aims to examine the impacts of the institutional structure on environmental sustainability in China. To this end, the study follows the method of cointegration with multiple breaks that produce robust econometric results and consider structural changes. According to the results, (i) the validity of an N-shaped EKC relationship is supported between economic growth and environmental pollution. (ii) Industrialization and trade have an increasing impact on environmental pollution. (iii) Political rights and civil liberties have a reducing effect on environmental pollution. Consequently, this study implies that political rights and civil liberties can make an important contribution to achieving sustainability goals in China.

The use of ecological footprint in estimating the Environmental Kuznets Curve hypothesis for BRICST by considering cross-section dependence and heterogeneity.

A vast body of literature estimates the impact of economic growth on environmental degradation in the framework of EKC model. Typical empirical studies proxy environmental degradation with CO2 emissions; however, this indicator does not consider the complex nature of environmental degradation. To fulfill this omission, ecological footprint that tracks the use of multiple categories of productive surface areas is used as proxy for the environment. Moreover, studies that do not consider issues of heterogeneity and cross-sectional dependence may not produce reliable outcomes. Hence, the present study re-investigates the validity of the EKC hypothesis for BRICST (Brazil, Russia, India, China, South Africa, Turkey) by using ecological footprint and considering the mentioned issues in the estimation process. Based on the annual data covering the period of 1980-2014, excluding Russia due to data unavailability, empirical results show that the EKC hypothesis is not valid, and energy intensity and energy structure are important determinants of environmental degradation. In line with the empirical outputs, possible policy suggestions are discussed in the present study.

Effect of diode laser application as an adjunct to nonsurgical periodontal therapy on the reduction of red complex microorganisms in type 2 diabetics with chronic periodontitis.

Bactericidal and detoxification effects of diode laser (DL) have been reported in periodontal treatment. The objective of this study was investigating the additional effect of DL with nonsurgical periodontal treatment on the red complex bacteria in type 2 diabetes mellitus (DM) patients with chronic periodontitis (CP). Sixty type 2 DM patients with chronic periodontitis (CP) were randomly assigned in two parallel groups to receive scaling root planning (SRP, n = 30) or SRP followed by DL periodontal pocket irradiation (SRP + DL, n = 30). Recording of clinical parameters and subgingival plaque sampling were performed at baseline, and post therapy (1 and 3 months after treatment). Amounts of Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia were evaluated with quantitative RT-PCR. Significant reductions for numbers of all three bacterial species were observed at 1 and 3 months compared with baseline for both treatments (p < 0.001), but no significant differences were found between two groups regarding bacterial reductions at these follow-up time points. No additional benefit of DL as an adjunct to nonsurgical periodontal therapy was recognized in the reduction of P. gingivalis, T. denticola, and T. forsythia for type 2 DM patients with CP. Further studies are required to clarify the effects of diode laser on the other periodontopathogens.

The shale gas production and economic growth in local economies across the US.

Recently, several seminal works have been drawing attention to the revolution of shale gas production technology of the USA, the impact of shale gas on energy sectors, as well as the influences of shale gas on macroeconomic variables of employment, economic growth, etc. Nevertheless, one may claim that two gaps appear in literature. The first gap is the absence of an econometric study estimating the effect of shale oil/gas on national economies. The more considerable second gap is the absence of econometric analyses revealing the impulses of shale gas on local economies. Therefore, this paper observes the possible causalities between the shale gas and local gross domestic product (GDP) employing quarterly data covering the period 2007-2016 for 12 states in the US. After performing the tests of cross-sectional dependence, heterogeneity, stationarity, and cointegration, the paper conducts the panel Granger causality analyses. The empirical findings depict that (i) there is available unidirectional relationship from local shale gas production to local GDP in Colorado, Ohio, and West Virginia; (ii) there occurs an impulse from GDP to local shale gas production for Louisiana, North Dakota, and Oklahoma; (iii) a bidirectional causality coexists between local shale gas production and GDP in Arkansas, California, and Texas; and (iv) there exists no association between local GDP and local shale gas extraction in Montana, New Mexico, and Wyoming.

Does globalization matter for environmental sustainability? Empirical investigation for Turkey by Markov regime switching models.

Many efforts have been made to theoretically explain and/or empirically investigate how globalization plays a role on environmental quality. However, as in theoretical explanations, empirical literature as well has not reached a consensus yet to enlighten possible effects in developing countries especially. On the one hand, Globalization is expected to contribute to decrease environmental degradation through the technique effect that underlines the role of obtaining clean technologies. On the other hand, this expectation may become reversed since globalization triggers economic activities through the scale effect and movements of dirty industries to developing countries. This paper focuses on how environmental sustainability reacts to globalization in Turkey. To this end, ecological footprint as a proxy for environmental sustainability and KOF globalization measurements are analyzed by using Markov regime switching models. Estimations indicate that growth in financial globalization, politic globalization, trade globalization, human capital, and capital stock reduce the ecological footprint growth of Turkey. Results reveal as well that interpersonal globalization growth diminishes ecological footprint growth. All three regime-switching models yield that growths of economic globalization and social globalization result in an increase in ecological footprint growth in Turkey.

The effect of energy R&D expenditures on CO2 emission reduction: estimation of the STIRPAT model for OECD countries.

Energy innovations are critical to combating global warming and climate change. In this context, we focus on the impact of energy research-development (R&D) expenditures, which are the input of energy innovations, on CO2 emissions. For this purpose, we investigate the effect of disaggregated energy R&D expenditures on CO2 emission in 19 high-income OECD countries over the period 2003-2015. The dynamic panel data method is followed for empirical analysis. The results of the study show that R&D expenditures for energy efficiency and fossil energy have an increasing effect on CO2 emissions. Contrary to expectations, there is no significant relationship between renewable energy R&D expenditures and CO2 emissions. Remarkably, there is strong evidence that the power and storage R&D expenditures have a reducing effect on CO2 emissions. In light of the empirical findings, policy implications and recommendations to potential readers and authorities are further discussed.

The impact of foreign direct investment on CO2 emissions in Turkey: new evidence from cointegration and bootstrap causality analysis.

Pollution haven hypothesis (PHH), which is defined as foreign direct investment inducing a raising impact on the pollution level in the hosting country, is lately a subject of discussion in the field of economics. This study, within the scope of related discussion, aims to look into the potential impact of foreign direct investments on CO2 emission in Turkey in 1974-2013 period using environmental Kuznets curve (EKC) model. For this purpose, Maki (Econ Model 29(5):2011-2015, 2012) structural break cointegration test, Stock and Watson (Econometrica 61:783-820, 1993) dynamic ordinary least square estimator (DOLS), and Hacker and Hatemi-J (J Econ Stud 39(2):144-160, 2012) bootstrap test for causality method are used. Research results indicate the existence of a long-term balance relationship between FDI, economic growth, energy usage, and CO2 emission. As per this relationship, in Turkey, (1) the potential impact of FDI on CO2 emission is positive. This result shows that PHH is valid in Turkey. (2) Moreover, this is not a one-way relationship; the changes in CO2 emission also affect FDI entries. (3) The results also provide evidence for the existence of the EKC hypothesis in Turkey. Within the frame of related findings, the study concludes several polities and presents various suggestions.

The influence of biomass energy consumption on CO2 emissions: a wavelet coherence approach.

In terms of today, one may argue, throughout observations from energy literature papers, that (i) one of the main contributors of the global warming is carbon dioxide emissions, (ii) the fossil fuel energy usage greatly contributes to the carbon dioxide emissions, and (iii) the simulations from energy models attract the attention of policy makers to renewable energy as alternative energy source to mitigate the carbon dioxide emissions. Although there appears to be intensive renewable energy works in the related literature regarding renewables' efficiency/impact on environmental quality, a researcher might still need to follow further studies to review the significance of renewables in the environment since (i) the existing seminal papers employ time series models and/or panel data models or some other statistical observation to detect the role of renewables in the environment and (ii) existing papers consider mostly aggregated renewable energy source rather than examining the major component(s) of aggregated renewables. This paper attempted to examine clearly the impact of biomass on carbon dioxide emissions in detail through time series and frequency analyses. Hence, the paper follows wavelet coherence analyses. The data covers the US monthly observations ranging from 1984:1 to 2015 for the variables of total energy carbon dioxide emissions, biomass energy consumption, coal consumption, petroleum consumption, and natural gas consumption. The paper thus, throughout wavelet coherence and wavelet partial coherence analyses, observes frequency properties as well as time series properties of relevant variables to reveal the possible significant influence of biomass usage on the emissions in the USA in both the short-term and the long-term cycles. The paper also reveals, finally, that the biomass consumption mitigates CO2 emissions in the long run cycles after the year 2005 in the USA.

Nonsurgical periodontal therapy with/without diode laser modulates metabolic control of type 2 diabetics with periodontitis: a randomized clinical trial.

In order to evaluate whether nonsurgical periodontal treatment with/without diode laser (DL) decontamination improves clinical parameters, the levels of IL-1ß, IL-6, IL-8, intercellular adhesion molecule (ICAM), and vascular cell adhesion molecule (VCAM) in gingival crevicular fluid and metabolic control (HbA1c) in chronic periodontitis (CP) patients with diabetes mellitus type 2 (DM2). Sixty patients with DM2 and CP were randomly assigned into two groups to receive scaling and root planing (SRP, n = 30) or SRP followed by diode laser application (SRP + DL, n = 30). Clinical periodontal and gingival crevicular fluid (GCF) parameters were assessed at baseline, 1, and 3 months after periodontal treatment. HbA1c levels were evaluated at baseline and 3 months post-therapy. Total amounts of cytokines and molecules were analyzed by ELISA. Nonsurgical periodontal treatment with/without DL appeared to improve clinical, biochemical parameters, and glycemic control in DM2 patients (BMI < 25 kg/m(2)) with CP. The SRP + DL group provided better reductions in probing depth (PD) and clinical attachment level (CAL) parameters compared to the SRP group (P < 0.05). Significant reductions were found in the total amounts of GCF levels of IL-1, IL-6, IL-8, ICAM, and VCAM after treatment (P < 0.05). HbA1c levels decreased significantly at 3 months after treatment (P < 0.05). SRP + DL reduced HbA1c levels more significantly compared to SRP alone (0.41 vs. 0.22 %, P < 0.05). SRP, especially in combination with DL, shows improvement of glycemic control for DM2 patients with CP.