Petroleum Business Review

Abstract This study aims to map the knowledge structure and elucidate the research trends related to the “sustainable supply chain” in the petrochemical industry. To this end, a total of 906 documents indexed in the Scopus database from 2000 to 2025 were collected and subjected to bibliometric analysis using VOSviewer and Biblioshiny tools. The results indicate that the scientific output in this field has experienced significant growth since 2010 and reached a maturity stage after 2019. Collaboration network analysis highlights the prominent role of the United States, the United Kingdom, and China in shaping the literature of this domain, alongside the gradually increasing contributions of countries such as Iran, Malaysia, and Brazil. Co-occurrence analysis of keywords reveals several established thematic clusters and interdisciplinary linkages among engineering, management, and environmental studies. By providing a comprehensive overview of the intellectual, conceptual, and social structure of the field, the findings of this study can serve as a foundation for guiding future research and supporting practical decision-making aimed at enhancing sustainability in the petrochemical supply chain.

Abstract Purpose: This study examines the impact of product diversification on asset returns in petrochemical companies using a kernel density approach, addressing contradictory findings in the diversification-performance literature within this capital-intensive sector.
Design/methodology/approach: Employing an ex-post facto research design, we analyzed data from petrochemical companies listed on the Tehran Stock Exchange from 2011 to 2021. The study utilized a two-stage analytical approach: first classifying companies into life cycle stages (growth, maturity, decline) using discriminant analysis, then testing hypotheses through multivariate regression and cross-sectional analysis. The kernel density estimation provided a non-parametric assessment of diversification effects.
Results: The results demonstrate that product diversification significantly enhances asset returns in petrochemical firms, with the Herfindahl index revealing seven distinct market concentration levels. The positive effect of diversification was particularly pronounced in monopolistic market structures. Empirical evidence confirms that diversification serves as an effective strategy for improving financial performance and mitigating market dependence.
Originality/value: This research contributes to the literature by introducing kernel density estimation to diversification analysis, providing a more nuanced understanding of return distributions beyond traditional parametric methods. The study also offers unique insights into the petrochemical sector's dynamics in emerging economies, highlighting how market structure moderates the diversification-performance relationship.
Practical implications: The findings suggest that managers should prioritize diversification strategies, especially in monopolistic environments, to enhance asset utilization and financial resilience. Policymakers can use these insights to design industrial policies that encourage strategic diversification in response to Iran's economic conditions.

Abstract In recent years, the completion of the value chain and increased exportation of petrochemical products have been utilized to offset oil and gas export losses. As a result, this may have created various challenges and complexities within the oil and gas industry. The study aims to identify key challenges confronting Iran's petrochemical industry, with a particular focus on regulatory issues. It seeks to distinguish and prioritize the most critical regulatory factors necessary for establishing an effective regulatory framework in the petrochemical sector. For this study, data was collected through several interviews and questionnaire with Iran's petrochemical experts. With the collected data, the Delphi method was utilized to help identify the most critical challenges. The impact and significance of each challenge were determined through statistical analysis. The research findings indicate that the most important challenges are the weakness of laws to attract foreign and domestic investors, the lack of trust and lack of integration in this industry from upstream to downstream sector, respectively. Also, based on the research results, it show that it is essential for Iran's petrochemical industry to have two regulatory agencies. The "Competition Council" and the "Securities and Exchange High Council" as regulators of the physical and financial markets are considered, however, for them to regulate effectively the overall structure of these councils must first be dramatically reformed. The important effective regulating factors which should be emphasized by the regulator in Iran's petrochemical industry were indicated and ranked as allocation, responsiveness, financial independence, legal independence and political independence.

Abstract One of the most important factors that investors pay attention to in stock markets is stock price fluctuations, which is the basis for evaluating the performance of company managers. The performance of the company's stock includes the yield from the resources under the company's control and is considered a suitable criterion for reaching the set goals. In the meantime, one of the things that influenced widely on the world financial markets is the outbreak of the 2019 Covid-19 epidemic. The Covid-19 pandemic is known as a black swan event since it was a rare, unexpected, unknown phenomenon with a high and universal impact. Therefore, the current research purpose is to investigate the fluctuations in the stock prices of petrochemical industry companies affected by the Covid-19 pandemic. For this purpose, 19 petrochemical companies of Tehran stock exchange were studied between 2017 to 2022. The data gathered daily and included 19 petrochemical companies in 220 working days for 5 years. The results showed that the shock caused by the growth of the corona virus initially caused a decrease in price volatility in petrochemical companies, but after two periods, the reaction of price volatility to the shock was positive. Finally, the shock effect disappeared after seven cycles.

Abstract As a significant consequence of internal and external characteristics in auditors, independence plays a vital role in promoting professional judgment in auditing. This dimension of individual audit functions has always been considered one of the areas studied in this profession due to its integration with the perceptual and often intangible features of auditors’ behavior. Therefore, this study, understanding the importance of independence functions in the auditing profession, seeks to identify the characteristics of inertia as a stimulus for independence in auditing in the petrochemical industry to act on its interpretive ranking. This research is a mixed method due to the nature of data collection. It first uses interviews to identify the characteristics of inertia in the auditing profession and then employs the checklists of the pair scale to determine the interpretive ranking. Accordingly, the grounded theory and the quantitative part are used in the qualitative part, and Delphi analysis and the interpretive ranking process are used. The statistical population in the qualitative section were 12 auditing professionals who, in terms of theoretical knowledge, had the necessary capabilities to develop the concept studied in this study. They were selected through theoretical sampling based on the snowball technique. The statistical population in the quantitative part were 19 auditors with work experience in the petrochemical industry and a level of technical and specialized knowledge; they were selected using homogeneous sampling. The research results in the qualitative part indicate the existence of 3 categories, 8 components, and 35 concept codes that have laid the inertial features in the auditing profession in the form of an 8-dimensional integrated model. On the other hand, the results in the quantitative part show that the percentage of influence of the locus of control feature is higher than other inertial features in the audit profession in the petrochemical industry, implying that the auditor’s encirclement on individual control in success and failure can avoid a set of external factors such as chance and lead fate in audit functions. In other words, an auditor with the characteristics of an internal locus of control tries to use his/her ability to express independent behavior in professional comments and judgments, regardless of external reasons

Abstract As one of the mother industries, the petrochemical industry is one of the essential pillars of development and the driving engine of various sectors of the country’s economy. This industry will achieve several important goals, such as increasing export income, expanding downstream sectors, creating jobs, and increasing GDP. This importance has been emphasized in the country’s upstream documents, such as the general policies of the resistance economy, focusing on developing petroleum refineries to prevent the vulnerability of oil and gas revenues by extending the value chain and increasing the export of these products. The current work aims to investigate the value chain of the petrochemical industry with the new approach of petrochemical refineries, as well as the pathology and evaluation of the current state of the chains mentioned above in the country with the descriptive research method and the library method using policy research. The research results show that the chain of petrochemical products with the approach of creating petrochemical refineries has relatively high advantages compared to focusing on chains with the traditional method.

Abstract Though it is generally accepted that information asymmetry has an impact on capital structure policy, the nature of the information asymmetry is not well understood. Recent theoretical works and empirical evidences suggest that financing choice depends upon the information asymmetry about investment risk of the particular use of funds (Halov & Heider, 2012) (Rao, Mohanty, & Baxamusa, 2015). Consistent with this view, we analyzed the data gathered among 199 companies listed in Tehran Stock Exchange during 2009-2016 by The Multiple Linear Regressions in order to test research’s hypotheses have been applied. We also examined the influence of Petrochemical industry on that relationship. The findings show that equity is used to fund projects with greater information asymmetry about their risk such as intangible assets and capital expenditure, while debt is used to fund investments with lower information asymmetry about their risk such as liquidity enhancement. We also found that the membership in petrochemical industry has no effect on the intangible assets and cash holding’s financing method, but concerning with capital expenditure and working capital the impact is significantly negative.