INFLUENCE OF ENVIRONMENTAL COSTS ON THE PERFORMANCE OF SOME SELECTED QUOTED MANUFACTURING COMPANIES IN NIGERIA

CHAPTER ONE: INTRODUCTION

1.1 Background of Study

The relationship between environmental costs and corporate financial performance has emerged as one of the most significant and debated issues in contemporary business management, accounting, and corporate governance. As global awareness of environmental degradation, climate change, and resource depletion has intensified, businesses have come under increasing pressure from multiple stakeholders—including governments, regulators, investors, customers, and civil society—to internalise the environmental costs of their operations. Manufacturing companies, particularly those in industries with high environmental impact (such as chemicals, cement, food and beverage, and packaging), face substantial environmental costs associated with pollution control, waste management, emissions reduction, environmental compliance, remediation of contaminated sites, and potential environmental liabilities. The question of whether these environmental costs impair or enhance corporate financial performance has profound implications for management decision-making, regulatory policy, and investment strategy (Gray and Bebbington, 2001; Schaltegger and Burritt, 2017; Porter and van der Linde, 1995a).

The concept of environmental costs encompasses a wide range of expenditures that manufacturing companies incur in their efforts to comply with environmental regulations, reduce their environmental footprint, prevent pollution, and remediate past environmental damage. These costs can be categorised into several types. Prevention costs are incurred to prevent environmental damage before it occurs, including investments in cleaner production technologies, process modifications, and environmental management systems. Detection costs are incurred to monitor and verify environmental compliance, including environmental monitoring equipment, testing, and auditing. Failure costs are incurred when environmental damage has occurred or regulations have been violated, including fines, penalties, clean-up costs, remediation expenses, and compensation for environmental damage. External costs are environmental damages caused by the company but borne by society (externalities), which may be internalised through taxes, fines, or regulatory requirements. The effective management of these environmental costs is essential for manufacturing companies to achieve both environmental and financial objectives (Schaltegger and Burritt, 2017; Epstein, 2018; USEPA, 1995).

The theoretical framework for understanding the relationship between environmental costs and financial performance draws from multiple perspectives that offer competing predictions. The traditional neoclassical perspective, grounded in the work of Friedman (1970), argues that environmental expenditures represent a financial burden that reduces profitability, as they divert resources from productive investments, increase operating costs, and create competitive disadvantages relative to firms with lower environmental standards. From this perspective, environmental costs are viewed as a necessary evil imposed by regulation, and the optimal response for firms is to minimise compliance costs while avoiding penalties. The empirical implication is that higher environmental costs should be associated with lower financial performance (Friedman, 1970; Palmer, Oates, and Portney, 1995).

In contrast, the resource-based perspective and the natural-resource-based view of the firm argue that environmental capabilities can be sources of competitive advantage. Firms that proactively invest in environmental management may develop unique capabilities—such as cleaner production technologies, eco-design expertise, waste reduction systems, and environmental management systems—that are valuable, rare, and difficult to imitate. These capabilities can lead to cost advantages (through reduced material and energy inputs, lower waste disposal costs, and lower compliance costs), differentiation advantages (through enhanced brand reputation, customer loyalty, and access to environmentally-sensitive markets), and risk reduction advantages (through lower exposure to environmental liabilities, regulatory sanctions, and reputational damage). The empirical implication is that strategic environmental investments can enhance financial performance, particularly when they are integrated into core business strategy rather than treated as compliance burdens (Hart, 1995; Barney, 1991; Russo and Fouts, 1997).

The Porter hypothesis, articulated by Porter and van der Linde (1995a, 1995b), provides a third perspective, arguing that properly designed environmental regulations can trigger innovation that more than offsets the costs of compliance. Strict but flexible environmental standards can create incentives for firms to innovate, developing new technologies, processes, and products that reduce environmental impact while also improving resource productivity, reducing costs, and enhancing competitiveness. The Porter hypothesis challenges the traditional trade-off thinking that environmental protection necessarily comes at the expense of economic performance. Empirical evidence on the Porter hypothesis is mixed, with some studies finding support (particularly for well-designed regulations that allow flexibility and encourage innovation) and others finding no effect or negative effects (Porter and van der Linde, 1995a, 1995b; Ambec, Cohen, Elgie, and Lanoie, 2013).

The concept of environmental costs has evolved significantly in the accounting literature, with the development of environmental management accounting (EMA) as a distinct field. EMA extends traditional management accounting by identifying, measuring, analysing, and reporting environmental costs that are often hidden in general overhead accounts. Environmental costs can be substantial in manufacturing industries, where material inputs, energy consumption, waste generation, and emissions are significant. Traditional accounting systems often fail to capture these costs, allocating them to general overhead accounts where they are not visible to managers. EMA provides tools for tracking environmental costs by product, process, or activity, enabling managers to identify cost-saving opportunities, improve resource efficiency, and make informed investment decisions. The implementation of EMA has been associated with improved environmental and financial performance in manufacturing companies (Burritt, Hahn, and Schaltegger, 2002; Jasch, 2009; IFAC, 2005).

The Nigerian manufacturing sector operates within a distinctive environmental regulatory framework that has evolved over several decades. The Federal Environmental Protection Agency (FEPA) was established in 1988 to coordinate environmental protection activities, but it was later replaced by the National Environmental Standards and Regulations Enforcement Agency (NESREA) under the NESREA Act of 2007. NESREA is responsible for enforcing environmental standards and regulations across all sectors of the Nigerian economy. Other regulatory bodies with environmental responsibilities include the National Oil Spill Detection and Response Agency (NOSDRA) for the oil and gas sector, and various state environmental protection agencies. Manufacturing companies in Nigeria are subject to environmental regulations covering air emissions, water pollution, waste management, hazardous substances, and environmental impact assessments for new projects (Federal Republic of Nigeria, 1988; Federal Republic of Nigeria, 2007; NESREA, 2019).

The key environmental regulations affecting manufacturing companies in Nigeria include the National Environmental (Air Quality Control) Regulations (2014), which set limits on emissions of pollutants such as particulate matter, sulphur dioxide, nitrogen oxides, and volatile organic compounds. The National Environmental (Base Metals, Iron and Steel Manufacturing/Recycling Industries Sector) Regulations (2011) and the National Environmental (Food and Beverage Sector) Regulations (2013) provide sector-specific requirements for manufacturing industries. These regulations require companies to install pollution control equipment, monitor emissions, report environmental performance, and comply with discharge limits. The costs of compliance with these regulations can be substantial, including capital expenditures for pollution control equipment, operating costs for monitoring and treatment, and administrative costs for reporting and record-keeping (NESREA, 2014; NESREA, 2011; NESREA, 2013).

In addition to regulatory compliance costs, manufacturing companies in Nigeria face environmental costs from voluntary environmental initiatives. Many companies, particularly those quoted on the Nigerian Exchange (NGX) and those operating as subsidiaries of multinational corporations, have adopted environmental management systems (e.g., ISO 14001 certification), implemented cleaner production programmes, invested in resource efficiency improvements, and engaged in corporate social responsibility (CSR) activities related to environmental protection. These voluntary investments may be motivated by stakeholder pressures (investors, customers, local communities), risk management concerns (reducing exposure to environmental liabilities), or strategic considerations (enhancing brand reputation and competitive positioning). The costs of voluntary environmental initiatives add to the environmental cost burden faced by manufacturing companies (Ike, 2017; Okafor and Okafor, 2015; Egbunike and Onyemachi, 2019).

The environmental challenges facing manufacturing companies in Nigeria are substantial and affect their cost structures. Inadequate waste management infrastructure means that companies must invest in their own waste treatment and disposal facilities. Irregular electricity supply forces companies to rely on diesel generators, which increase air emissions and fuel costs. Water scarcity and pollution require companies to invest in water treatment and recycling systems. The costs associated with these challenges are environmental costs that affect financial performance. For example, a beverage company that must purify water to meet production standards incurs environmental costs that a company in a country with treated municipal water supplies would not face. These context-specific environmental challenges make Nigeria a unique setting for studying the relationship between environmental costs and financial performance (Ogwu, 2018; Uche, 2019; Adeyemi, 2017).

The performance of manufacturing companies in Nigeria has been a subject of concern for policymakers and stakeholders. The manufacturing sector’s contribution to Gross Domestic Product (GDP) has declined substantially from its peak in the 1970s and 1980s, when manufacturing accounted for approximately 10-15% of GDP, to less than 10% in recent years. Nigerian manufacturers face multiple challenges, including inadequate infrastructure (particularly electricity and transportation), policy inconsistency, currency volatility, import competition, and financing constraints. In this challenging environment, the additional burden of environmental costs may affect the viability and competitiveness of manufacturing companies. However, environmental costs may also create opportunities for efficiency improvements, innovation, and competitive differentiation. Understanding the influence of environmental costs on financial performance is essential for managers, investors, and policymakers (CBN, 2020; NBS, 2019; Okonkwo, 2018; Ogbu, 2017).

The concept of corporate performance is multi-dimensional, encompassing financial performance, operational performance, and market performance. Financial performance is typically measured by profitability ratios (such as return on assets (ROA), return on equity (ROE), and profit margin), which indicate how efficiently a company generates profits from its resources. Operational performance is measured by efficiency indicators (such as asset turnover, inventory turnover, and cost efficiency). Market performance is measured by stock market indicators (such as share price, market capitalisation, and Tobin’s Q). In the environmental cost literature, researchers have used various performance measures, with ROA and ROE being the most common. The relationship between environmental costs and performance may differ depending on which performance measure is used: environmental costs may reduce short-term profitability while enhancing long-term competitiveness and market value (Eccles, Ioannou, and Serafeim, 2014; Orlitzky, Schmidt, and Rynes, 2003; Margolis, Elfenbein, and Walsh, 2009).

The empirical literature on the relationship between environmental costs and financial performance has produced mixed findings, reflecting differences in methodology, measurement, context, and time period. Some studies have found a negative relationship, supporting the traditional view that environmental costs reduce profitability. Other studies have found a positive relationship, supporting the resource-based view and Porter hypothesis that environmental investments enhance performance. Still other studies have found no significant relationship or a relationship that is contingent on firm characteristics (industry, size, regulatory environment, management quality). The mixed findings suggest that the relationship is context-dependent and that the specific mechanisms linking environmental costs to performance matter. For Nigeria, where empirical research on environmental accounting is limited, there is a need for rigorous, context-specific analysis (Ambec et al., 2013; Dixon-Fowler, Slater, Johnson, Ellstrand, and Romi, 2013; Endrikat, Guenther, and Hoppe, 2014).

The selection of quoted manufacturing companies for this study is strategic for several reasons. Quoted companies (listed on the Nigerian Exchange, NGX) are subject to disclosure requirements that provide accessible financial data for analysis. Quoted companies are generally larger and more established, with more formal environmental management systems. Quoted companies face pressure from investors, analysts, and regulators that may influence their environmental practices. The manufacturing sector includes companies with diverse environmental profiles, including high-impact industries (cement, chemicals, food and beverage, packaging) and lower-impact industries, enabling comparative analysis. By focusing on quoted manufacturing companies, the study can analyse a relatively homogeneous set of firms with available data and environmental cost disclosures (NGX, 2020; Okafor and Okafor, 2015; Egbunike and Onyemachi, 2019).

The period of analysis (2007-2020 or the most recent available data) is appropriate because it captures the period following the establishment of NESREA (2007) and the strengthening of Nigeria’s environmental regulatory framework. The period includes the implementation of major sector-specific environmental regulations, including the Food and Beverage Sector Regulations (2013) and the Air Quality Control Regulations (2014). The period also includes the adoption of corporate governance codes (2006, 2011, 2018) that include provisions on environmental and social responsibility. The financial performance data for this period are available from company annual reports and the Nigerian Exchange. The period provides sufficient observations for econometric analysis while reflecting the contemporary regulatory environment (NESREA, 2019; SEC, 2019; NGX, 2020).

The measurement of environmental costs in financial statements presents challenges. Accounting standards do not require separate disclosure of most environmental costs, which are typically aggregated into general expense accounts (e.g., “administrative expenses,” “selling and distribution expenses”) or included in cost of goods sold. Environmental liabilities, such as provisions for remediation, are disclosed when they meet recognition criteria. Some companies voluntarily disclose environmental costs in their annual reports or sustainability reports, but the quality and completeness of disclosure vary substantially. Researchers must therefore use proxies for environmental costs, such as environmental compliance expenditures reported in sustainability reports, estimated pollution abatement costs based on industry characteristics, or the use of dummy variables indicating environmental certification or disclosure. This study will analyse the environmental cost disclosures of selected quoted manufacturing companies, using content analysis to identify and quantify reported environmental costs (Egbunike and Onyemachi, 2019; Okafor, 2017; Uche, 2019).

The practical implications of understanding the influence of environmental costs on performance are substantial for Nigerian manufacturing companies. If environmental costs are found to be associated with lower performance, managers may focus on cost minimisation and regulatory compliance. If environmental costs are found to be associated with higher performance, managers may view environmental investments as strategic opportunities for innovation, differentiation, and competitive advantage. Investors may use environmental performance as a criterion for investment decisions, favouring companies that manage environmental costs effectively. Regulators may design policies that encourage proactive environmental management rather than punitive compliance. The findings of this study will contribute to these practical decisions by providing evidence from the Nigerian context (Porter and van der Linde, 1995a; Hart, 1995; Schaltegger and Burritt, 2017).

1.2 Statement of Problems

Despite the growing importance of environmental management and the substantial environmental costs incurred by manufacturing companies in Nigeria, the influence of these costs on corporate financial performance remains inadequately understood. Nigerian manufacturing companies face increasing pressure from regulators, investors, customers, and communities to improve their environmental performance, yet the financial implications of environmental investments are not well documented. Managers lack empirical evidence on whether environmental expenditures are a drain on profitability or a source of competitive advantage. Investors lack information on how environmental performance affects financial returns. Policymakers lack evidence on the economic consequences of environmental regulation. The gap between the need for evidence and the availability of rigorous empirical research constitutes the central problem addressed by this study (Egbunike and Onyemachi, 2019; Okafor and Okafor, 2015; Ike, 2017).

The first critical problem concerns the limited disclosure of environmental costs in the financial statements of Nigerian manufacturing companies. While some companies voluntarily report environmental expenditures in annual reports or separate sustainability reports, the quality, completeness, and comparability of such disclosures are limited. Many environmental costs are aggregated into general expense accounts, making it difficult for stakeholders to identify the magnitude and trend of environmental expenditures. Researchers face challenges in measuring environmental costs, relying on proxies or limited disclosure data. The problem is that without adequate disclosure, the influence of environmental costs on performance cannot be reliably assessed, and managers, investors, and regulators lack the information needed for decision-making (Egbunike and Onyemachi, 2019; Okafor, 2017; Uche, 2019).

The second critical problem concerns the theoretical ambiguity and mixed empirical evidence on the relationship between environmental costs and financial performance. The traditional view holds that environmental costs reduce profitability, while the resource-based view and Porter hypothesis suggest that strategic environmental investments can enhance performance. Empirical studies in developed economies have produced mixed results, and very few rigorous studies have been conducted on Nigerian manufacturing companies. The problem is that without Nigeria-specific empirical evidence, managers cannot determine whether environmental investments are likely to benefit or harm their companies’ financial performance, and policymakers cannot assess the likely economic impact of environmental regulations (Ambec et al., 2013; Endrikat et al., 2014; Okafor and Okafor, 2015; Egbunike and Onyemachi, 2019).

The third critical problem concerns the potential endogeneity between environmental costs and financial performance. It is possible that more profitable companies invest more in environmental management (because they have resources to do so), rather than environmental investments causing higher profitability. Alternatively, companies with poor environmental performance may face higher costs (fines, penalties, remediation) that reduce profitability. The direction of causality is important for policy and management: if environmental investments cause higher profitability, companies should be encouraged to invest; if profitability enables environmental investments, policies that improve profitability may indirectly improve environmental performance. Most Nigerian studies have not adequately addressed endogeneity, limiting the validity of their findings (Okafor and Okafor, 2015; Egbunike and Onyemachi, 2019).

The fourth critical problem concerns the sectoral heterogeneity in environmental costs and their performance effects. Manufacturing companies in different subsectors (e.g., cement, food and beverage, chemicals, packaging) face different environmental challenges, different regulatory requirements, and different cost structures. The influence of environmental costs on performance may vary across sectors: in some sectors, environmental investments may be more easily recouped through efficiency savings or product differentiation; in other sectors, environmental costs may be pure compliance burdens with no offsetting benefits. Most Nigerian studies have aggregated across sectors or focused on a single sector, limiting the ability to identify sectoral differences. The problem is that without sector-specific analysis, recommendations may not be appropriately targeted (Egbunike and Onyemachi, 2019; Okafor, 2017).

The fifth critical problem concerns the time horizon over which environmental costs influence performance. Environmental investments often have long payback periods: capital expenditures for pollution control equipment may take years to generate returns through reduced compliance costs or improved efficiency. Proactive environmental management may enhance brand reputation and customer loyalty over the long term. Conversely, the costs of environmental non-compliance (fines, penalties, remediation, reputational damage) may persist for years. Most Nigerian studies have used short time periods (3-5 years) that may not capture the long-term effects of environmental investments. The problem is that without longer-term analysis, the full influence of environmental costs on performance may be underestimated or mis-specified (Egbunike and Onyemachi, 2019; Okafor and Okafor, 2015).

1.3 Aim of the Study

The specific aim of this research work is to empirically examine the influence of environmental costs on the financial performance of selected quoted manufacturing companies in Nigeria, with a particular focus on quantifying the relationship between environmental cost components and profitability measures, analysing the moderating effects of firm characteristics on this relationship, testing for causality and endogeneity, and developing recommendations for environmental cost management and disclosure.

1.4 Objectives of the Study

1. To identify and measure the environmental costs incurred by selected quoted manufacturing companies in Nigeria, including prevention costs, detection costs, and failure costs, based on available disclosures.

2. To examine the relationship between environmental costs and financial performance (profitability, return on assets, return on equity) of selected quoted manufacturing companies in Nigeria.

3. To analyse the moderating effects of firm size, industry sector, and environmental certification on the relationship between environmental costs and financial performance.

4. To test for causality and address potential endogeneity in the relationship between environmental costs and financial performance, distinguishing whether environmental investments cause higher profitability or profitable companies invest more in environmental management.

5. To develop recommendations for environmental cost management, environmental disclosure, and regulatory policy based on the empirical findings of the study.

1.5 Research Questions

1. What environmental costs are incurred by selected quoted manufacturing companies in Nigeria, and how are these costs disclosed in their annual reports and sustainability reports?

2. What is the relationship between environmental costs and the financial performance (profitability, return on assets, return on equity) of selected quoted manufacturing companies in Nigeria?

3. How do firm size, industry sector, and environmental certification moderate the relationship between environmental costs and financial performance among selected quoted manufacturing companies in Nigeria?

4. Does environmental cost cause financial performance, or does financial performance cause environmental investment, or is the relationship bidirectional?

5. What recommendations can be developed for environmental cost management, environmental disclosure practices, and regulatory policy to enhance the financial performance implications of environmental investments?

1.6 Research Hypotheses

Hypothesis 1

H0₁: Environmental costs have no significant effect on the financial performance (ROA, ROE) of selected quoted manufacturing companies in Nigeria.

H1₁: Environmental costs have a significant effect on the financial performance (ROA, ROE) of selected quoted manufacturing companies in Nigeria.

Hypothesis 2

H0₂: The relationship between environmental costs and financial performance does not differ significantly across industry sectors (e.g., cement, food and beverage, chemicals, packaging).

H1₂: The relationship between environmental costs and financial performance differs significantly across industry sectors.

Hypothesis 3

H0₃: Firm size does not significantly moderate the relationship between environmental costs and financial performance.

H1₃: Firm size significantly moderates the relationship between environmental costs and financial performance.

Hypothesis 4

H0₄: There is no significant causal relationship from environmental costs to financial performance; any observed correlation is due to reverse causality (profitable companies investing more in environmental management).

H1₄: There is a significant causal relationship from environmental costs to financial performance, independent of reverse causality.

Hypothesis 5

H0₅: The level of environmental cost disclosure in Nigerian manufacturing companies does not significantly affect the relationship between environmental costs and financial performance.

H1₅: The level of environmental cost disclosure significantly affects the relationship between environmental costs and financial performance.

1.7 Justification of the Study

This study is justified by the critical importance of environmental management for the sustainability and competitiveness of Nigerian manufacturing companies. Manufacturing is a strategic sector for economic diversification, employment generation, and industrialisation, but it is also a source of significant environmental pressure. As environmental regulations intensify and stakeholder expectations rise, manufacturing companies must manage environmental costs effectively to remain viable. However, the empirical evidence on how environmental costs affect financial performance in Nigeria is extremely limited. Managers lack guidance on whether environmental investments are likely to pay off. Investors lack information for incorporating environmental factors into investment decisions. Policymakers lack evidence for designing cost-effective environmental regulations. This study addresses these gaps by providing rigorous, context-specific empirical evidence on the influence of environmental costs on the financial performance of quoted manufacturing companies in Nigeria (Egbunike and Onyemachi, 2019; Okafor and Okafor, 2015; Ike, 2017; Adeyemi, 2017).

1.8 Significance of the Study

This study makes significant contributions to multiple stakeholder groups with interests in environmental management and corporate performance in Nigeria. For managers of manufacturing companies, the study provides empirical evidence on the financial implications of environmental costs, enabling more informed decisions about environmental investments, cost management, and strategy. For investors and financial analysts, the study provides insights into how environmental performance affects financial returns, supporting environmental, social, and governance (ESG) integration in investment decisions. For regulators including NESREA and the Federal Ministry of Environment, the study provides evidence on the economic consequences of environmental regulation, informing policy design and enforcement strategies. For standard-setters including the Financial Reporting Council of Nigeria, the study provides evidence on the need for improved environmental cost disclosure requirements. For academic researchers in environmental accounting and corporate finance, the study contributes to the limited empirical literature on environmental costs and performance in developing economies, testing and extending theories developed primarily in Western contexts. For the Nigerian public and local communities affected by manufacturing pollution, the study promotes corporate accountability for environmental impacts and provides evidence on the trade-offs between environmental protection and economic performance (Egbunike and Onyemachi, 2019; Okafor and Okafor, 2015; Schaltegger and Burritt, 2017; Epstein, 2018).

1.9 Scope of the Study

The scope of this study is delimited to an examination of the influence of environmental costs on the financial performance of selected quoted manufacturing companies in Nigeria. The study focuses specifically on manufacturing companies listed on the Nigerian Exchange (NGX), excluding financial services, oil and gas, telecommunications, and other non-manufacturing sectors. The study examines environmental costs as defined in the environmental accounting literature: prevention costs (expenditures to prevent environmental damage), detection costs (monitoring and verification), and failure costs (remediation, fines, penalties). The study measures financial performance using accounting-based measures (return on assets, return on equity, profit margin) and, where available, market-based measures (share price, Tobin’s Q). The study covers the period from 2007 (establishment of NESREA) to the most recent year of available data (2019 or 2020). The study does not include non-quoted manufacturing companies, which may have different environmental practices and disclosure patterns. The study does not include the oil and gas sector, which is subject to different environmental regulations and cost structures. The study does not include state-owned manufacturing enterprises. The study relies on publicly available data from annual reports, sustainability reports, and the Nigerian Exchange; it does not include proprietary data or primary data collection from companies.

1.10 Definition of Terms

Environmental Costs: Expenditures incurred by a company to prevent, detect, remedy, or compensate for environmental damage, including prevention costs (cleaner production, pollution control equipment), detection costs (environmental monitoring, auditing), and failure costs (remediation, fines, penalties) (USEPA, 1995; Schaltegger and Burritt, 2017).

Prevention Costs: Environmental costs incurred to prevent environmental damage before it occurs, including investments in cleaner production technologies, process modifications, environmental management systems, and employee training (USEPA, 1995; Jasch, 2009).

Detection Costs: Environmental costs incurred to monitor and verify environmental compliance, including environmental monitoring equipment, testing, auditing, and reporting (USEPA, 1995; Burritt, Hahn, and Schaltegger, 2002).

Failure Costs: Environmental costs incurred when environmental damage has occurred or regulations have been violated, including fines, penalties, clean-up costs, remediation expenses, and compensation for environmental damage (USEPA, 1995; Epstein, 2018).

Financial Performance: The financial results of a company’s operations, typically measured by profitability ratios including return on assets (net income divided by total assets), return on equity (net income divided by shareholders’ equity), and profit margin (net income divided by revenue) (Orlitzky, Schmidt, and Rynes, 2003; Eccles, Ioannou, and Serafeim, 2014).

Return on Assets (ROA) : A profitability ratio calculated as net income divided by total assets, indicating how efficiently a company uses its assets to generate profits (Okafor and Okafor, 2015; Egbunike and Onyemachi, 2019).

Return on Equity (ROE) : A profitability ratio calculated as net income divided by shareholders’ equity, indicating the return generated on shareholders’ investments (Okafor and Okafor, 2015; Egbunike and Onyemachi, 2019).

Environmental Management Accounting (EMA) : The identification, measurement, analysis, and reporting of environmental costs and their financial implications, integrating environmental information into management accounting systems (IFAC, 2005; Burritt, Hahn, and Schaltegger, 2002).

Porter Hypothesis: The proposition that properly designed environmental regulations can trigger innovation that more than offsets the costs of compliance, enhancing competitiveness (Porter and van der Linde, 1995a, 1995b; Ambec et al., 2013).

Natural-Resource-Based View (NRBV) : A strategic management framework that argues that firms can achieve competitive advantage through environmental capabilities that are valuable, rare, and difficult to imitate (Hart, 1995).

Quoted Manufacturing Companies: Manufacturing companies whose shares are listed (quoted) on the Nigerian Exchange (NGX), subject to NGX listing requirements, disclosure rules, and corporate governance codes (NGX,

CHAPTER TWO: LITERATURE REVIEW

2.1 Theoretical Review

The theoretical foundation for examining the influence of environmental costs on the performance of quoted manufacturing companies in Nigeria draws from multiple theoretical perspectives in strategic management, environmental economics, accounting, and corporate finance. This section critically reviews the principal theories informing understanding of the relationship between environmental costs and financial performance, including the neoclassical economics perspective, the resource-based view of the firm, the natural-resource-based view, stakeholder theory, legitimacy theory, the Porter hypothesis, and environmental management accounting theory.

2.1.1 Neoclassical Economics Perspective

The neoclassical economics perspective, rooted in the work of Friedman (1970) and traditional microeconomic theory, provides the foundational framework for understanding the traditional view that environmental costs represent a financial burden that reduces corporate profitability. From this perspective, firms operate within a competitive market environment where profit maximisation is the primary objective. Environmental regulations impose costs on firms—such as expenditures for pollution control equipment, waste treatment, monitoring, and reporting—that do not contribute directly to productive output or revenue generation. These costs increase the firm’s cost of production, reducing profit margins, and put the firm at a competitive disadvantage relative to firms in jurisdictions with weaker environmental standards or relative to firms that evade compliance (Friedman, 1970; Palmer, Oates, and Portney, 1995; Jaffe, Peterson, Portney, and Stavins, 1995).

The neoclassical perspective argues that environmental regulations force firms to internalise externalities—the environmental damages that were previously borne by society. While internalisation is socially desirable (it corrects market failures), it imposes private costs on firms without generating offsetting private benefits. The costs of compliance are deadweight losses from the firm’s perspective, reducing the resources available for investment in productive activities, research and development, or shareholder returns. The theory predicts a negative relationship between environmental costs and financial performance: firms that incur higher environmental costs will have lower profitability, all else equal. The magnitude of the negative effect depends on the stringency of environmental regulations, the competitiveness of product markets (ability to pass costs forward to customers), and the availability of cost-effective compliance options (Palmer et al., 1995; Jaffe et al., 1995; Walley and Whitehead, 1994).

The neoclassical perspective has been influential in shaping the policy debate on environmental regulation, particularly in the United States during the 1970s and 1980s when environmental regulations were perceived as a drag on economic growth. However, the perspective has been criticised for assuming that environmental costs are purely burdensome and that firms have no ability to innovate or find cost-saving opportunities in environmental management. Critics argue that the neoclassical perspective ignores the potential for “win-win” opportunities—environmental improvements that also reduce costs or enhance revenues. The empirical evidence on the relationship between environmental costs and performance has challenged the simple negative relationship predicted by neoclassical theory, with many studies finding no significant relationship or even a positive relationship (Ambec et al., 2013; Porter and van der Linde, 1995a; Hart, 1995).

The application of the neoclassical perspective to Nigerian manufacturing companies must consider the competitive environment in which Nigerian firms operate. Nigerian manufacturers face intense competition from imports, particularly from Asia, which may have lower environmental standards and lower compliance costs. In this context, environmental costs may indeed be a burden that reduces competitiveness. However, Nigerian manufacturers also face context-specific environmental challenges (inadequate waste management infrastructure, water scarcity, electricity unreliability) that may create opportunities for efficiency improvements. The net effect of environmental costs on performance in Nigeria is an empirical question that this study addresses (Ogwu, 2018; Uche, 2019; Adeyemi, 2017).

2.1.2 Resource-Based View of the Firm

The resource-based view (RBV) of the firm, developed by Barney (1991) and Wernerfelt (1984), provides a strategic management framework for understanding how firms can achieve competitive advantage through the acquisition, development, and deployment of valuable, rare, imperfectly imitable, and non-substitutable (VRIN) resources. Unlike the neoclassical perspective, which views firms as identical in their cost structures and technology, RBV emphasises firm heterogeneity: firms differ in their resource endowments, and these differences can be sources of sustained competitive advantage. From an RBV perspective, environmental capabilities—such as pollution prevention technologies, waste reduction systems, environmental management systems, and eco-design expertise—can be VRIN resources that generate competitive advantage (Barney, 1991; Wernerfelt, 1984; Peteraf, 1993).

Environmental capabilities may generate cost advantages through improved resource productivity. Firms that invest in pollution prevention and waste reduction often discover that reducing waste also reduces material and energy inputs, lowering production costs. The Toyota production system, which emphasises waste reduction (including environmental waste), is a classic example of how environmental improvements can generate cost savings. Environmental capabilities may generate differentiation advantages through enhanced brand reputation, customer loyalty, and access to environmentally-sensitive market segments. Firms with strong environmental performance may command price premiums, increased market share, or preferred supplier status. Environmental capabilities may generate risk reduction advantages by reducing exposure to environmental liabilities, regulatory sanctions, reputational damage, and shareholder activism (Hart, 1995; Russo and Fouts, 1997; Sharma and Vredenburg, 1998).

The RBV perspective predicts a positive relationship between environmental investments and financial performance, but only when those investments develop VRIN capabilities. Not all environmental investments are strategic: compliance-oriented investments that simply meet regulatory minimums may not generate competitive advantage because they are easily imitated by competitors. Proactive environmental investments that go beyond compliance, that are integrated into core business strategy, and that develop unique organisational capabilities are more likely to generate positive performance effects. The relationship between environmental costs and performance is therefore contingent on the strategic nature of the environmental investments (Hart, 1995; Russo and Fouts, 1997; Christmann, 2000).

The application of RBV to Nigerian manufacturing companies must consider the resource endowments of Nigerian firms. Nigerian manufacturers may have limited financial resources for proactive environmental investments, and the institutional environment (weak enforcement, corruption) may reduce the competitive advantage from environmental capabilities. However, Nigerian firms that develop environmental capabilities may differentiate themselves in export markets where environmental standards are higher, or may attract foreign investment from multinationals seeking environmentally responsible suppliers. The RBV perspective provides a framework for understanding why some Nigerian manufacturers may benefit from environmental investments while others do not (Ike, 2017; Okafor and Okafor, 2015; Egbunike and Onyemachi, 2019).

2.1.3 Natural-Resource-Based View of the Firm

The natural-resource-based view (NRBV) of the firm, developed by Hart (1995), extends the resource-based view to explicitly incorporate the natural environment as a strategic factor. Hart (1995) argued that as environmental constraints intensify (resource depletion, pollution, climate change, population growth), firms that develop capabilities to address these constraints will achieve competitive advantage. The NRBV identifies three interconnected strategic capabilities: pollution prevention (reducing emissions, waste, and effluents), product stewardship (integrating environmental concerns into product design and lifecycle management), and sustainable development (addressing environmental constraints in the firm’s value chain and the broader social context). Each capability is associated with different sources of competitive advantage (Hart, 1995; Hart and Dowell, 2011).

Pollution prevention capabilities focus on minimising emissions, waste, and effluents at the source, rather than treating them after they are created. These capabilities generate cost advantages through reduced material and energy inputs, lower waste disposal costs, and reduced compliance costs. The continuous improvement orientation of pollution prevention is consistent with total quality management (TQM) principles. Product stewardship capabilities extend environmental management beyond the firm’s boundaries to include the entire product lifecycle: design, raw material extraction, manufacturing, distribution, use, and disposal. These capabilities generate differentiation advantages through enhanced brand reputation, customer loyalty, and access to green markets. Sustainable development capabilities address the firm’s role in broader social and environmental challenges, such as poverty, inequality, and resource scarcity. These capabilities generate competitive advantage through positioning for future regulatory changes, building relationships with stakeholders, and creating barriers to imitation (Hart, 1995; Sharma and Vredenburg, 1998; Hart and Dowell, 2011).

The NRBV predicts that firms that develop these environmental capabilities will achieve superior financial performance over the long term. However, the relationship is not automatic: environmental investments may take years to generate returns; firms may face short-term costs while developing capabilities; and the benefits may depend on the firm’s strategic positioning and industry context. The NRBV also recognises that environmental capabilities are path-dependent: firms that have invested in environmental management over time develop knowledge, routines, and relationships that are difficult for competitors to imitate. This path dependence creates first-mover advantages for firms that adopt proactive environmental strategies early (Hart, 1995; Russo and Fouts, 1997; Aragon-Correa and Sharma, 2003).

The application of the NRBV to Nigerian manufacturing companies must consider the stage of environmental management development in Nigeria. Most Nigerian manufacturers are likely still in the pollution prevention stage, focusing on compliance with basic regulations rather than product stewardship or sustainable development. However, Nigerian firms that export to developed economies may be compelled to adopt product stewardship practices to meet international standards. The NRBV provides a framework for understanding how Nigerian firms can progress along the environmental capability continuum and how each stage relates to financial performance (Ike, 2017; Okafor, 2017; Egbunike and Onyemachi, 2019).

2.1.4 Stakeholder Theory

Stakeholder theory, developed by Freeman (1984) and subsequent scholars, provides a framework for understanding how firms manage relationships with multiple stakeholders who have interests in corporate environmental performance. Stakeholders include primary stakeholders (shareholders, employees, customers, suppliers) and secondary stakeholders (local communities, regulators, non-governmental organisations, the media, the general public). Each stakeholder group has legitimate expectations regarding corporate environmental behaviour, and firms that fail to meet these expectations face risks (regulatory sanctions, consumer boycotts, employee turnover, community opposition) that can harm financial performance. Conversely, firms that manage stakeholder relationships effectively can build trust, legitimacy, and social capital that enhance financial performance (Freeman, 1984; Donaldson and Preston, 1995; Clarkson, 1995).

From a stakeholder theory perspective, environmental costs are incurred to meet stakeholder expectations. Regulatory stakeholders (government agencies) impose compliance costs; firms that violate regulations face fines, penalties, and legal costs. Customer stakeholders may prefer environmentally responsible products, creating market opportunities for firms that invest in environmental quality. Employee stakeholders may prefer to work for environmentally responsible employers, affecting recruitment, retention, and productivity. Community stakeholders may oppose polluting facilities, causing delays, litigation, and reputational damage. Investor stakeholders increasingly consider environmental performance in investment decisions, affecting cost of capital and share price. The stakeholder theory perspective predicts that firms that manage environmental costs effectively—by anticipating stakeholder expectations and investing proactively—will achieve better financial performance than firms that react defensively to stakeholder pressures (Freeman, 1984; Clarkson, 1995; Donaldson and Preston, 1995).

Stakeholder theory also explains variation in environmental performance across firms: firms facing greater stakeholder pressures (e.g., visible consumer brands, firms in sensitive locations, firms with institutional investors) are more likely to invest in environmental management. In the Nigerian context, quoted manufacturing companies face stakeholder pressures from multiple sources: regulatory pressure from NESREA, community pressure from host communities affected by pollution, customer pressure from consumers and industrial buyers, and investor pressure from institutional shareholders and stock exchange listing requirements. The stakeholder theory perspective provides a framework for understanding why some Nigerian manufacturers incur higher environmental costs than others and how these costs affect performance (Egbunike and Onyemachi, 2019; Okafor, 2017; Uche, 2019).

The stakeholder salience framework (Mitchell, Agle, and Wood, 1997) identifies three attributes that determine which stakeholders receive managerial attention: power (ability to influence the firm), legitimacy (perceived validity of their claims), and urgency (time-sensitivity of their claims). Stakeholders with all three attributes are most salient. For Nigerian manufacturers, regulatory stakeholders (NESREA) have high power, legitimacy, and urgency, making them highly salient. Community stakeholders may have high legitimacy but variable power; they become more salient when they take disruptive action (protests, blockades). Investor stakeholders have high power (they can sell shares, vote proxies, engage management) and increasing legitimacy as environmental, social, and governance (ESG) investing grows. Understanding stakeholder salience helps explain variation in environmental investments (Mitchell, Agle, and Wood, 1997; Okafor, 2017).

2.1.5 Legitimacy Theory

Legitimacy theory, rooted in institutional sociology (Suchman, 1995; Dowling and Pfeffer, 1975), provides a framework for understanding why firms voluntarily disclose environmental information and invest in environmental management. Legitimacy is defined as “a generalised perception or assumption that the actions of an entity are desirable, proper, or appropriate within some socially constructed system of norms, values, beliefs, and definitions” (Suchman, 1995, p. 574). Firms seek to maintain legitimacy because illegitimate firms face risks: loss of customers, difficulty attracting employees, regulatory scrutiny, negative media coverage, and shareholder activism. Environmental performance affects legitimacy because environmental damage is increasingly viewed as illegitimate behaviour in contemporary society (Suchman, 1995; Dowling and Pfeffer, 1975; Deegan, 2002).

Legitimacy theory predicts that firms will manage their environmental performance and environmental disclosures to maintain or restore legitimacy. When a firm experiences a legitimacy-threatening event (e.g., an environmental spill, a regulatory violation, negative media coverage), it will engage in legitimation strategies: changing its environmental practices, making symbolic gestures, or increasing environmental disclosures. Firms also proactively build legitimacy by adopting environmental management systems, obtaining environmental certifications (e.g., ISO 14001), and disclosing environmental information in annual reports. The cost of these legitimacy-building activities is an environmental cost that affects financial performance, but the cost of illegitimacy (reputational damage, regulatory sanctions) may be even higher (Deegan, 2002; Gray, Kouhy, and Lavers, 1995; Patten, 2002).

Legitimacy theory has been extensively applied to explain environmental disclosure practices. Firms in highly visible industries (oil and gas, chemicals, mining) and firms with poor environmental performance tend to disclose more environmental information, consistent with legitimacy theory predictions. For Nigerian manufacturing companies, legitimacy concerns may drive environmental investments and disclosures. Companies that export to developed economies may face legitimacy pressures from international customers and regulators. Companies located in environmentally sensitive areas or areas with active civil society may face legitimacy pressures from local communities. Quoted companies face legitimacy pressures from investors and the stock exchange. Legitimacy theory provides a framework for understanding why Nigerian manufacturers incur environmental costs even when direct financial returns are uncertain (Egbunike and Onyemachi, 2019; Okafor, 2017; Uche, 2019).

The relationship between legitimacy and financial performance is complex. In the short term, legitimacy-building activities (environmental investments, certifications, disclosures) impose costs that may reduce profitability. However, in the long term, maintaining legitimacy may protect the firm from costly conflicts (community protests, boycotts, litigation) and may enhance stakeholder relationships that support performance. The net effect of legitimacy-seeking environmental costs on performance depends on the firm’s legitimacy risk: firms with high legitimacy risk (visible, controversial industries) may benefit more from legitimacy-building investments (Deegan, 2002; Patten, 2002; Okafor, 2017).

2.1.6 Porter Hypothesis

The Porter hypothesis, articulated by Porter and van der Linde (1995a, 1995b), challenges the traditional neoclassical view that environmental regulation imposes costs that harm competitiveness. The hypothesis argues that properly designed environmental regulations can trigger innovation that more than offsets the costs of compliance. When regulations are strict but flexible (allowing firms to find the most cost-effective solutions), when they provide long-term certainty (enabling firms to plan investments), and when they encourage rather than stifle innovation, they can create “win-win” outcomes: environmental improvements accompanied by enhanced competitiveness. The Porter hypothesis has been highly influential in policy debates, though empirical evidence remains mixed (Porter and van der Linde, 1995a, 1995b; Ambec et al., 2013).

The Porter hypothesis identifies several mechanisms through which environmental regulation can enhance competitiveness. First, regulation signals resource inefficiencies that firms had not previously recognised; pollution is often a form of economic waste (inefficient use of materials, energy, or resources). By reducing pollution, firms also reduce resource inputs and waste disposal costs. Second, regulation creates pressure that stimulates innovation; without regulatory pressure, firms may be complacent about environmental inefficiencies. Third, regulation can create first-mover advantages for firms that innovate in response to regulation, enabling them to export technologies and processes to firms in jurisdictions with weaker regulations. Fourth, regulation can improve product quality, as environmentally conscious consumers may prefer products from firms with strong environmental performance (Porter and van der Linde, 1995a, 1995b; Ambec et al., 2013).

The Porter hypothesis distinguishes between the static effects of regulation (the immediate compliance costs) and the dynamic effects (innovation-driven cost reductions over time). In the static view, regulation imposes costs. In the dynamic view, regulation stimulates innovation that reduces costs over time, potentially leading to net benefits. The hypothesis does not claim that all environmental regulations generate net benefits; poorly designed regulations (prescriptive, inflexible, short-term) may not trigger innovation and may indeed harm competitiveness. The design of regulation matters: performance-based standards (specifying environmental outcomes) are more likely to stimulate innovation than technology-based standards (specifying specific technologies) (Porter and van der Linde, 1995a; Ambec et al., 2013).

The application of the Porter hypothesis to Nigeria must consider the nature of Nigeria’s environmental regulations. Nigeria’s regulations include both performance-based standards (e.g., emission limits) and technology-based requirements (e.g., pollution control equipment). Enforcement has historically been weak, reducing the pressure on firms to innovate. However, as enforcement strengthens and as Nigerian firms export to markets with higher environmental standards, the Porter hypothesis may become more relevant. The empirical testing of the Porter hypothesis in Nigeria is limited, providing an opportunity for this study (Uche, 2019; Adeyemi, 2017; Okafor, 2017).

2.1.7 Environmental Management Accounting Theory

Environmental management accounting (EMA) theory, developed by Burritt, Hahn, and Schaltegger (2002), Jasch (2009), and the International Federation of Accountants (IFAC, 2005), provides a practical framework for identifying, measuring, analysing, and reporting environmental costs. EMA extends traditional management accounting by making environmental costs visible to managers. Traditional accounting systems typically allocate environmental costs to general overhead accounts, where they are “hidden” and not attributed to specific products, processes, or activities. EMA traces environmental costs to the activities that cause them, enabling managers to identify cost-saving opportunities, evaluate environmental investments, and make informed decisions (Burritt, Hahn, and Schaltegger, 2002; Jasch, 2009; IFAC, 2005).

EMA distinguishes between different types of environmental costs. Conventional costs are raw material and energy costs that have environmental implications but are typically captured in conventional accounting. Hidden costs are environmental costs that are captured in accounting systems but allocated to general overhead where they are not visible to managers (e.g., environmental monitoring, record-keeping, reporting). Contingent costs are environmental costs that may occur in the future (e.g., remediation costs, legal liabilities, fines). Image and relationship costs are intangible costs related to environmental performance (e.g., brand reputation, customer loyalty, community relations). External costs are environmental damages caused by the firm but borne by society (externalities). Each type of cost requires different measurement approaches and has different implications for decision-making (USEPA, 1995; IFAC, 2005; Jasch, 2009).

EMA provides tools for environmental cost allocation, including activity-based costing (ABC), which traces environmental costs to the activities that cause them; material flow cost accounting (MFCA), which tracks material and energy flows through the production process, identifying losses and inefficiencies; and lifecycle costing (LCC), which considers environmental costs over the entire product lifecycle. These tools enable managers to identify the most cost-effective environmental investments, to price products to reflect their environmental costs, and to evaluate the financial implications of environmental decisions (Burritt, Hahn, and Schaltegger, 2002; Jasch, 2009; Schaltegger and Burritt, 2017).

The application of EMA to Nigerian manufacturing companies is limited by data availability and accounting system capabilities. Many Nigerian companies have not implemented EMA systems, and environmental costs remain hidden in general overhead. However, the growing demand for environmental disclosure from investors, regulators, and customers may drive EMA adoption. This study, by analysing the relationship between environmental costs and performance, provides evidence that may support the business case for EMA adoption in Nigeria (Egbunike and Onyemachi, 2019; Okafor, 2017; Ike, 2017).

2.2 Conceptual Framework

The conceptual framework for this study specifies the relationship between environmental costs (independent variables) and financial performance (dependent variable) of quoted manufacturing companies in Nigeria. The framework identifies the components of environmental costs, the dimensions of financial performance, and the moderating variables that affect this relationship.

2.2.1 Independent Variables: Environmental Cost Components

The first independent variable is prevention costs, defined as environmental expenditures incurred to prevent environmental damage before it occurs. Prevention costs include investments in cleaner production technologies (equipment that reduces emissions, effluents, or waste at the source), process modifications (changes to production processes that reduce environmental impact), environmental management systems (ISO 14001 certification, environmental policy development, staff training), and eco-design (designing products to reduce environmental impact throughout the lifecycle). Prevention costs are expected to have a positive effect on financial performance in the long term (through efficiency gains and risk reduction) but may have a negative effect in the short term (due to upfront investment costs) (USEPA, 1995; Epstein, 2018; Schaltegger and Burritt, 2017).

The second independent variable is detection costs, defined as environmental expenditures incurred to monitor and verify environmental compliance. Detection costs include environmental monitoring equipment (air emissions monitors, water quality testing equipment), environmental testing (sampling and analysis), environmental auditing (internal and external audits of environmental performance), and environmental reporting (preparation of environmental reports, regulatory submissions). Detection costs are typically viewed as necessary compliance costs with limited potential for value creation, though effective monitoring can identify inefficiencies and prevent costly failures (USEPA, 1995; IFAC, 2005; Jasch, 2009).

The third independent variable is failure costs, defined as environmental expenditures incurred when environmental damage has occurred or regulations have been violated. Failure costs include remediation costs (clean-up of contaminated sites), fines and penalties (regulatory sanctions for non-compliance), legal costs (defence of environmental claims, litigation), and compensation payments (damages to affected parties). Failure costs are expected to have a negative effect on financial performance, as they represent value destruction rather than value creation. Firms with high failure costs are likely to have lower profitability. Failure costs also include less tangible costs such as reputational damage, loss of customer goodwill, and increased regulatory scrutiny (USEPA, 1995; Epstein, 2018).

2.2.2 Dependent Variables: Financial Performance Dimensions

The first dependent variable is return on assets (ROA), calculated as net income divided by total assets. ROA measures how efficiently a company uses its assets to generate profits. Environmental costs affect ROA through both the numerator (net income) and the denominator (total assets). Prevention costs increase total assets (if capitalised) and reduce net income (if expensed). Failure costs reduce net income directly. The net effect on ROA depends on the magnitude and timing of environmental costs and their impact on revenues (through improved reputation, customer loyalty, or market access) (Okafor and Okafor, 2015; Egbunike and Onyemachi, 2019).

The second dependent variable is return on equity (ROE), calculated as net income divided by shareholders’ equity. ROE measures the return generated on shareholders’ investments. Environmental costs affect ROE through their impact on net income. Because equity is the residual after liabilities, environmental liabilities (provisions for remediation) reduce equity, affecting the denominator. ROE is particularly relevant for investors, as it measures the return they receive on their investment (Okafor and Okafor, 2015; Egbunike and Onyemachi, 2019).

The third dependent variable is profit margin, calculated as net income divided by revenue. Profit margin measures how much profit a company generates from each naira of sales. Environmental costs affect profit margin by increasing costs (reducing margin) or by enabling revenue increases (through access to green markets, price premiums, or enhanced reputation). Profit margin is a useful performance measure because it isolates the cost and pricing effects from the asset base effects captured in ROA and ROE (Orlitzky, Schmidt, and Rynes, 2003; Endrikat, Guenther, and Hoppe, 2014).

2.3 Summary of Literature Review in Tabular Format

Author(s) and Year	Strengths of the Study	Weaknesses of the Study	Limitations of the Study	Gaps Identified
Friedman (1970)	Articulated classic neoclassical position that social responsibility reduces profits; highly influential in policy debates	Normative rather than empirical; does not consider innovation or strategic differentiation	Theoretical essay with no empirical testing	Empirical testing in developing economy manufacturing not conducted
Porter and van der Linde (1995a, 1995b)	Developed Porter hypothesis arguing regulation can stimulate innovation; shifted policy debate	Based on case studies; critics argue evidence is anecdotal; “win-win” opportunities may be limited	Case study methodology with limited statistical generalisation	Empirical testing in Nigerian manufacturing not conducted; regulatory design in Nigeria not analysed
Hart (1995)	Developed natural-resource-based view of the firm; integrated environmental strategy into strategic management	Theoretical framework with limited initial empirical testing; many subsequent empirical studies	Theoretical development with case study illustration	Application to Nigerian manufacturing not examined; NRBV capabilities in Nigeria not assessed
Barney (1991)	Developed resource-based view of the firm; foundational framework for strategic management	VRIN criteria difficult to operationalise; tautological tendencies (successful firms have valuable resources)	Theoretical framework with extensive empirical testing in developed economies	Application to environmental resources in