Vertical structure and efficiency assessment of the US oil and gas companies

Abstract

Global warming and climate change have been critical global issues in recent years. Investors and consumers expect corporate management to battle these issues and guarantee the sustainability of the firm and society. Operational and environmental efficiency assessments would be an effective first step toward sustainable management for firms. This study examines two types of unified efficiency measures—operational and environmental—for 34 US oil and gas companies over the period 2011–2015. The data set comprises seven major petroleum companies (integrated firms) and 27 independent companies. Integrated companies operate along the entire supply chain from upstream exploration to downstream retailing. On the contrary, independent firms only engage in upstream activities, such as exploration and development. This study measures unified efficiency by applying non-radial DEA models to the data set. The Kruskal-Wallis rank sum test is applied to examine whether the two types of unified efficiency measures change over time and whether there are differences between integrated and independent oil and gas companies. The results reveal that integrated companies outperformed independent ones in environmental efficiency. The reasons are the higher environmental protection standards at integrated companies and their efforts in consumer-targeted strategic branding to promote sales.