Voluntary environmental programs have proven to be a viable tool of pollution abatement, supplementing the command-and-control approach and market-based policies such as emissions trading and taxes. ...These voluntary initiatives aim to achieve pollution reduction through several channels, including procedural changes, raw material changes, product and packaging redesign, and innovation in pollution control technologies. The ISO 14001 standard is such a voluntary program; first introduced in 1996 by the International Organization for Standardization (ISO), it has steadily grown since and has been widely adopted by organizations around the world. In this paper, we empirically study the effects of the ISO 14001 standard on carbon emissions using a panel dataset of Korean manufacturing firms. As the largest contributor to the warming of the earth's atmosphere, carbon emissions are the focus of national and international efforts to curb climate change. The Korean manufacturing industry is responsible for about 40% of greenhouse gases in the country and has experienced rapid growth in ISO 14001 certified facilities. Our econometric results indicate that ISO 14001 certification spurs a significant reduction in carbon emissions among certified firms, after accounting for its potential endogeneity with an instrumental variable strategy. The empirical results suggest that wider ISO 14001 certification among carbon-intensive industries can be a credible pathway to help achieve the Korean government's goal of cutting domestic carbon emissions by 37% by 2030.
•Impact of ISO 14001 certification on carbon emissions at the firm level.•Econometric analysis based on panel data of South Korean firms for the 2011–14 period.•The South Korean manufacturing industry is responsible for about 40% of greenhouse gases in the country.•The results show that ISO adoption spurs a 34% reduction in carbon emissions on average.•The reductions are larger in the first years after certification but linger for a number of years.
We explore the role of ISO 14001 certification in stimulating increased exports for certified firms. The rationale for the study is that certification conveys an important market signal that the ...certified firm's production process adheres to internationally accepted standards of environmental quality. That is, the perceived credibility of ISO 14001 certification lowers informational barriers about the environmental attributes of the certified firm's products, especially in foreign markets, boosting exports. We put this proposition to an empirical test using the gravity trade model and a panel of South Korean manufacturing industries exporting to 176 countries over the 1988–2015 period. Our results show that ISO 14001 certification generates a robust positive push effect for South Korean manufacturing exports. We further find that this effect varies based on the level of economic development of the destination market, with a more pronounced impact of certification on exports to high‐income countries than to middle and lower income countries.
This dissertation explores the effects of adopting ISO 14001, an international voluntary environmental program, on a firm's economic and environmental performance.The first chapter empirically ...investigates the economic benefits of adopting ISO 14001 on technical efficiency. The ISO 14001 program seeks to continually reduce inefficient resource usage and waste generation in the production process through the implementation of an environmental management system. Furthermore, through employee training, ISO 14001 can infuse a cost-saving mindset that permeates company-wide. Therefore, firms that adopt the program can expect efficiency improvements. The stochastic frontier approach is used to measure the individual firm’s inefficiency, while an instrumental variable approach is employed to account for the potential endogeneity of ISO adoption. Using a panel of South Korean manufacturing firms, the results reveal that the adoption of ISO 14001 significantly improves firm efficiency with an estimated 3.2 percent boost in output value, on average. The disaggregated analysis by the industrial sectors, based on pollution intensity, shows that low polluting firms experience significant efficiency improvements while high polluting firms do not. In other words, the overall positive effect of ISO is largely spurred by significant efficiency gains among low-polluting firms.In the second chapter, the gravity model is employed to examine whether or not the adoption of ISO 14001 boosts the volume of exports of the adopting firms. ISO 14001 can act as an eco-label in the international trade market, because the certification is audited by a third party, which represents identifiable information about a firm’s environmental record. We also analyze whether the effect differs based on destination countries, due to different levels of environmental governance and interests. We use the Poisson Pseudo Maximum Likelihood estimator with various fixed effects to account for zero-value trade data and heteroscedasticity-induced inconsistency in linear models (Santos-Silva and Tenreyro, 2006). Industry-level export panel data from South Korea to the various destination countries over the 1988-2015 period is analyzed. The results indicate that ISO 14001 has a positive impact on the export volume of the ISO certified South Korean firms. Furthermore, the size of the impact varies with the level of the economic development of the export destination countries. In particular, the impact is significantly larger when the importers are economically developed countries, implying that ISO 14001 is effective in circumventing stricter environmental requirements and mitigating the risk of export barriers.The third chapter analyzes the impact of ISO 14001 certification on environmental performance in South Korea using data on greenhouse gas (CO2) emissions from 2011 to 2014. Many of the benefits of ISO discussed in previous studies (e.g., reputational effect, compliance effect) are based on the expectation that firms would actually improve their environmental performance by adopting ISO 14001. An instrumental variable approach is employed to identify the causal effect of ISO 14001 on CO2 emissions. The empirical findings reveal that a firm’s ISO 14001 adoption significantly reduces the total amount of greenhouse gas emissions, as well as the intensity, on average. Furthermore, the results illustrate the possibility of a learning effect of ISO 14001; as firms accumulate experience with ISO 14001, their emissions decrease further.
Objectives
The purpose of this study was to evaluate the 10-year overall survival and local tumor progression (LTP) of percutaneous radiofrequency ablation (RFA) for single nodular hepatocellular ...carcinoma (HCC) < 3 cm using a large longitudinal hospital registry and clinical factors associated with overall survival and LTP.
Methods
A total of 467 newly diagnosed patients with single nodular HCC < 3 cm who underwent RFA as first-line therapy between January 2008 to December 2016 were analyzed. Overall survival and LTP were estimated using the Kaplan-Meier method. Cox regression and competing risks Cox regression analysis were performed to identify prognostic factors for overall survival and LTP, respectively.
Results
The 5- and 10-year overall survival rates after RFA were 83.7% and 74.2%, respectively. LTP (hazard ratio (HR), 2.03; 95% confidence interval (CI), 1.19–3.47) was one of the important factors for overall survival after RFA. The 5- and 10-year LTP rates after RFA were 20.4% and 25.1%, respectively. Periportal location (subdistribution HR, 2.29; 95% CI, 1.25–4.21), subphrenic location (2.25, 1.34–3.86), size ≥ 1.5–< 2.0 cm (1.88, 1.05–3.39), and size ≥ 2.0 cm (2.10, 1.14–3.86) were independent factors for LTP.
Conclusion
Ten-year therapeutic outcomes of percutaneous RFA as first-line therapy were excellent for single HCC < 3 cm. LTP was an important prognostic factor for overall survival after RFA. Periportal and subphrenic location of HCCs and tumor size were predictors for the development of LTP after RFA.
Key Points
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Updated 10-year survival outcome of percutaneous radiofrequency ablation as first-line therapy for single hepatocellular carcinoma < 3 cm was higher than previously reported
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Local tumor progression was an important prognostic factor for overall survival after percutaneous radiofrequency ablation
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Periportal and subphrenic location of hepatocellular carcinomas and tumor size were predictors for the development of local tumor progression after percutaneous radiofrequency ablation
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Background and Aim
Non‐alcoholic fatty liver disease (NAFLD) is a multisystem disease associated with an increased risk of cardiovascular disease (CVD), diabetes, and chronic kidney disease. Indeed, ...CVD is the most common cause of death in NAFLD patients. This study aimed to evaluate the association between NAFLD and the risk of incident myocardial infarction.
Methods
This is a retrospective cohort study involving 111 492 adults over 40 years old without history of CVD, liver disease, or cancer at baseline who participated in a regular health screening exam between 2003 and 2013. Fatty liver was diagnosed by ultrasonography.
Results
During 725 706.9 person‐years of follow‐up, 183 participants developed myocardial infarction (incidence rate 0.3 cases per 1000 person‐years). The age, sex, and year of visit‐adjusted hazard ratio (HR) for incident myocardial infarction comparing participants with NAFLD with those without it was 2.14 (95% confidence interval 1.59, 2.89). This association remained significant in fully adjusted models (HR 1.54; 95% confidence interval 1.11, 2.14). Compared with participants without NAFLD, in participants with low NAFLD fibrosis score (NFS) (< −1.455) and with intermediate‐to‐high NFS (≥ −1.455), the fully adjusted HRs for incident myocardial infarction were 1.70 (1.22, 2.36) and 1.88 (1.24, 2.87), respectively.
Conclusion
In this large cohort study, NAFLD was associated with an increased incidence of myocardial infarction independently of established risk factors. In addition, this association was similar in participants with and without evidence of more advanced NAFLD as indicated by the NFS. NAFLD patients may need to be carefully monitored and managed early to prevent myocardial infarction.
