This chapter is dedicated to defining the role of accounting and accounting principles in relation to evaluating corporate performance. This analysis concentrates on firm-level reporting for two main reasons. First, from a historical standpoint, the focus of reporting has traditionally been on a firm as an organization that interacts with its internal and external stakeholders as well as with other companies in the supply chain. Second, firm-level reporting is essential for understanding supply chain-level impacts: After all, any analysis of value-chain effects requires a precise and comparable assessment of aggregated and consolidated outcomes at the firm-level. Moreover, this focus on the corporate (micro-)level of analysis anticipates a discussion of the elements and dynamics involved in the core focus at the supply chain level, as discussed in Chap. 4 . To that end, this chapter illustrates the evolution of stakeholders’ expectations that has prompted a move toward new methodologies and standards that can be used to estimate firms’ financial and non-financial impacts, such as integrated reporting (IR) and the Global Reporting Initiative (GRI). These tools help analyze the informational needs of various stakeholders and, by extension, broaden the scope and transparency of reporting. Consequently, scholars have shifted their attention to identifying the scope of disclosure in line with the double materiality perspective.