THE ROLE OF ACCOUNTING IN THE CONTROL OF PUBLIC EXPENDITURE IN NIGERIA (A CASE STUDY OF CENTRAL BANK OF NIGERIA)

CHAPTER ONE: INTRODUCTION

1.1 Background of Study

The control of public expenditure is a fundamental pillar of sound public financial management, democratic accountability, and good governance in any nation. Public expenditure refers to the spending by government entities of public funds—resources collected from taxpayers, borrowed from domestic and international sources, or derived from natural resources (such as oil revenues in Nigeria). Effective control of public expenditure ensures that public resources are spent as intended by law (legality), that they are spent efficiently (economy and efficiency), that they achieve their intended purposes (effectiveness), and that they are properly accounted for (accountability). The consequences of weak expenditure control are severe: waste, fraud, corruption, macroeconomic instability (excessive deficits and inflation), and poor service delivery. Accounting, as a discipline and profession, provides the informational, analytical, and control tools essential for effective public expenditure control (Premchand, 1993; Khan and Hildreth, 2002; IMF, 2001).

The role of accounting in public expenditure control encompasses multiple dimensions that span the entire budget cycle: from planning and appropriation to execution, reporting, and audit. At the planning stage, accounting provides historical data on past expenditures, enabling realistic budget formulation. At the appropriation stage, accounting ensures that appropriations are properly recorded and classified. At the execution stage, accounting provides the systems (budgetary accounting, commitment accounting, payment processing) that ensure that expenditures do not exceed appropriations (budgetary control) and that payments are properly authorised, supported by documentation, and recorded accurately. At the reporting stage, accounting provides information on actual expenditures compared to budgets (variance analysis), enabling management and oversight bodies to identify problems and take corrective action. At the audit stage, accounting provides the records and evidence needed for internal and external auditors to verify compliance and detect irregularities (Premchand, 1993; Lienert, 2003; Diamond, 2006).

The Nigerian public financial management system has undergone significant reforms over the past two decades to improve expenditure control, transparency, and accountability. The historical context of weak expenditure control in Nigeria includes episodes of massive corruption, budget indiscipline, and financial mismanagement that have undermined development. The military regimes (1966-1979, 1983-1999) were characterised by limited transparency, weak accountability, and significant misappropriation of public funds. The return to democratic governance in 1999 created an opportunity for comprehensive reform. The Federal Government, with support from international development partners (World Bank, IMF, DFID, EU), implemented a series of public financial management reforms: the introduction of the Treasury Single Account (TSA) to consolidate government cash resources; the implementation of the Integrated Payroll and Personnel Information System (IPPIS) to eliminate ghost workers and payroll fraud; the deployment of the Government Integrated Financial Management Information System (GIFMIS) to automate budget execution, accounting, and reporting; the establishment of the Bureau for Public Procurement (BPP) to regulate procurement; and the strengthening of internal and external audit (Okonjo-Iweala, 2012; World Bank, 2010; CBN, 2015).

The Central Bank of Nigeria (CBN), as the apex financial institution and banker to the Federal Government, plays a pivotal role in the control of public expenditure. The CBN acts as the government’s banker, maintaining the Consolidated Revenue Fund (CRF) accounts through which most government expenditures are processed. The CBN operates the Treasury Single Account (TSA), which consolidates government funds at the central bank, enabling better cash management and reducing the risk of idle cash balances in commercial banks. The CBN also processes government payments, ensuring that payments are authorised, supported by documentation, and within approved appropriations. The CBN provides accounting and reporting services to government, including the preparation of bank reconciliation statements and financial reports. The CBN also contributes to the oversight of public expenditure through its internal audit function and its role in the audit committee of the Federal Government (CBN, 1991; CBN, 2015; Okonjo-Iweala, 2012).

The statutory framework for public expenditure control in Nigeria is established by the Constitution of the Federal Republic of Nigeria (1999, as amended), the Finance (Control and Management) Act, the Appropriation Act, the Public Procurement Act, the Fiscal Responsibility Act, and the Treasury Circulars and Financial Regulations issued by the Accountant-General of the Federation. The Constitution establishes the Consolidated Revenue Fund (CRF) into which all government revenues must be paid and from which expenditures must be authorised. The Appropriation Act provides legal authority for spending, specifying the amounts appropriated for each ministry, department, and agency (MDA). The Fiscal Responsibility Act establishes fiscal rules (including the prohibition of overdrafts from the CBN except in limited circumstances) and requires fiscal transparency. The Public Procurement Act establishes rules for government procurement to ensure competition, value for money, and transparency. These laws provide the legal framework within which accounting for expenditure control operates (Federal Republic of Nigeria, 1999; Federal Republic of Nigeria, 2007; Federal Republic of Nigeria, 2008).

The concept of public expenditure control encompasses several distinct but interrelated types of control. Legal control ensures that expenditures are authorised by law (appropriation) and that they comply with legal requirements. Budgetary control ensures that expenditures do not exceed appropriated amounts and that they are used for the purposes specified in the budget. Administrative control ensures that expenditures are properly authorised, documented, and processed in accordance with regulations. Accounting control ensures that expenditures are accurately recorded, classified, and reported. Internal control ensures that there are systems in place to prevent and detect errors, irregularities, and fraud. Audit control provides independent assurance that the other controls are effective. Accounting plays a role in all of these control types, providing the information and systems needed for control to operate effectively (Premchand, 1993; Khan and Hildreth, 2002; Lienert, 2003).

The budget cycle provides the temporal framework for public expenditure control. The budget cycle has four phases: formulation (preparation of the budget by the Executive), approval (legislative appropriation), execution (spending by MDAs), and audit (review by the Auditor-General). Accounting is involved in all phases. During formulation, accounting provides historical data and cost estimates. During approval, accounting ensures that appropriations are properly recorded. During execution, accounting provides the systems for controlling spending (commitment accounting, payment processing, variance analysis). During audit, accounting provides the records and evidence needed for audit. The effectiveness of expenditure control depends on the quality of accounting at each phase. Weaknesses at any phase can undermine overall control (Premchand, 1993; IMF, 2001).

The Government Integrated Financial Management Information System (GIFMIS) is the central accounting system for the Federal Government of Nigeria. GIFMIS is an information technology system that integrates budget formulation, budget execution, accounting, reporting, and cash management. GIFMIS replaces the previous fragmented, manual systems that were prone to error, delay, and manipulation. GIFMIS provides real-time information on budget releases, commitments, payments, and balances, enabling MDAs and central agencies (Ministry of Finance, Accountant-General, CBN) to monitor expenditure control in real time. GIFMIS also automates controls, such as preventing payments that would exceed appropriations (budgetary control), ensuring that payments are properly authorised (administrative control), and providing an audit trail for transactions (accounting control). The implementation of GIFMIS has significantly improved Nigeria’s expenditure control capacity (Okonjo-Iweala, 2012; World Bank, 2010; Accountant-General, 2018).

The Treasury Single Account (TSA) is another critical reform that has enhanced expenditure control. Before the TSA, government funds were held in thousands of accounts across commercial banks, making it difficult for the government to know its cash position, to manage liquidity efficiently, and to prevent the accumulation of idle cash balances that could be misappropriated. The TSA consolidates all government funds in a single account (or a set of linked accounts) at the CBN. Expenditure control is enhanced because payments can only be made from the TSA, ensuring that all spending is centralised and monitored. The TSA also prevents MDAs from maintaining “off-budget” accounts that are not subject to oversight. The CBN, as the operator of the TSA, plays a central role in this control mechanism (Okonjo-Iweala, 2012; CBN, 2015; Accountant-General, 2018).

The Integrated Payroll and Personnel Information System (IPPIS) is a reform specifically aimed at controlling personnel expenditure, which accounts for a significant proportion of government spending. Before IPPIS, Nigeria experienced significant payroll fraud, including “ghost workers” (individuals who were not legitimate employees but were receiving salaries), “ghost pensioners,” and manipulation of salary grades and allowances. IPPIS integrates payroll and personnel data, ensuring that only verified employees are paid, that payments are calculated correctly based on approved salary structures, and that changes (hiring, termination, promotion) are properly authorised and recorded. IPPIS is controlled by the Accountant-General’s office, but the CBN processes the payments through the TSA. The system has reportedly saved billions of naira by eliminating ghost workers (Okonjo-Iweala, 2012; Accountant-General, 2018).

The role of accounting in preventing unauthorised and unsupported expenditures is particularly important. Unauthorised expenditures are payments made without legal appropriation or that exceed the appropriated amount. Unsupported expenditures are payments made without adequate documentation (e.g., no contract, no invoice, no delivery note, no approval). Accounting systems should include controls that prevent such expenditures: commitment accounting (ensuring that funds are reserved for future obligations), pre-audit of payments (verifying that supporting documentation is complete and that the payment complies with regulations), and segregation of duties (ensuring that the person who authorises the payment is not the same person who processes it or reconciles the account). The CBN, as payment processor, plays a key role in ensuring that payments are authorised and supported before funds are released (Premchand, 1993; Lienert, 2003; IMF, 2001).

The role of accounting in detecting and correcting expenditure irregularities is also critical. Even with strong preventive controls, errors and irregularities may occur. Accounting systems should have detective controls: bank reconciliations (comparing CBN records to MDA records), variance analysis (comparing actual expenditures to budgets), and exception reporting (identifying unusual transactions for investigation). The CBN prepares bank reconciliation statements for government accounts, comparing its records of payments and receipts to the records maintained by the Accountant-General and MDAs. Discrepancies are investigated and corrected. The CBN also provides data to the Auditor-General for the annual external audit, which provides independent assurance on the regularity and propriety of expenditures (CBN, 2015; Accountant-General, 2018; Auditor-General, 2018).

The limitations of accounting in expenditure control must also be acknowledged. Accounting can only provide information about what has already happened (historical information). It cannot predict future problems or prevent all irregularities. Accounting is dependent on the quality of source documents and data entry; if documents are falsified or data entry errors occur, accounting records will be inaccurate. Accounting systems can be circumvented by management override or collusion. Accounting controls are only as effective as the people who implement them; if staff are incompetent, unmotivated, or corrupt, controls will fail. Accounting is also subject to reporting lags; by the time a problem is detected, significant funds may have been misappropriated. These limitations mean that accounting must be part of a broader public financial management framework that includes strong internal controls, independent audit, legislative oversight, and anti-corruption enforcement (Premchand, 1993; Diamond, 2006; Khan and Hildreth, 2002).

1.2 Statement of Problems

Despite the existence of a legal framework, accounting systems (GIFMIS, TSA, IPPIS), and oversight institutions (CBN, Accountant-General, Auditor-General) for public expenditure control in Nigeria, persistent evidence indicates that expenditure control remains weak, with significant leakages, irregularities, and inefficiencies. The Auditor-General of the Federation’s annual reports consistently identify billions of naira in unauthorised expenditures, unsupported payments, procurement irregularities, and other financial management deficiencies across Ministries, Departments, and Agencies (MDAs). The gap between the formal controls prescribed by law and regulation and the actual effectiveness of expenditure control in practice constitutes the central problem addressed by this study (Auditor-General, 2018; Accountant-General, 2018; Okonjo-Iweala, 2012).

The first critical problem concerns the effectiveness of GIFMIS as an expenditure control tool. While GIFMIS has automated many manual processes and introduced controls (e.g., preventing payments that exceed appropriations), evidence suggests that GIFMIS is not fully effective. Some MDAs continue to maintain off-budget accounts outside GIFMIS, circumventing controls. There are reports of system manipulation, where users override controls or create fictitious transactions. The integration between GIFMIS, TSA, and IPPIS is not seamless, creating opportunities for error and fraud. The problem is that without a fully effective GIFMIS, expenditure control remains compromised, and the CBN (as the payment processor) may be processing payments that have not been adequately controlled (Okonjo-Iweala, 2012; World Bank, 2010; Accountant-General, 2018).

The second critical problem concerns the Treasury Single Account (TSA) and its implementation. While the TSA has consolidated government funds, there are persistent issues: some MDAs continue to maintain accounts outside the TSA, particularly in the health and education sectors where development partners require separate accounts. The waiver process for these accounts is not always transparent or well-controlled. There are also reports of delays in payment processing through the TSA, leading to cash flow problems for MDAs and suppliers. The problem is that if the TSA is not fully implemented or is implemented inefficiently, its benefits for expenditure control are reduced, and the CBN’s role in expenditure control becomes more difficult (Okonjo-Iweala, 2012; CBN, 2015; Accountant-General, 2018).

The third critical problem concerns the Integrated Payroll and Personnel Information System (IPPIS). While IPPIS has successfully eliminated many ghost workers, there are persistent issues: some MDAs have not been fully integrated into IPPIS, maintaining separate payroll systems. There are reports of manipulation of IPPIS data, including unauthorised additions to payroll and failure to remove terminated employees. There are also reports of “ghost pensioners” (pensioners who do not exist or who are dead but continue to receive pensions). The problem is that personnel expenditure remains a significant area of leakage, despite the existence of IPPIS, and the CBN (as payment processor) may be making payments that are not properly authorised or verified (Okonjo-Iweala, 2012; Accountant-General, 2018; Auditor-General, 2018).

The fourth critical problem concerns the role of the CBN in authorising and processing payments. The CBN processes payments based on authorisations from MDAs and the Accountant-General. If the authorisation is fraudulent or if the underlying documentation is inadequate, the CBN may process an improper payment. The CBN relies on the Accountant-General’s office and MDAs to ensure that payments are properly authorised and supported. There have been reports of fraud where fraudsters used fake authorisations to divert government funds, and the CBN processed the payments because the authorisation appeared legitimate. The problem is that the CBN’s role in expenditure control is limited to processing; it does not have the mandate or capacity to verify the underlying legitimacy of every payment. This limitation creates a vulnerability (CBN, 2015; Auditor-General, 2018; Okonjo-Iweala, 2012).

The fifth critical problem concerns the quality of accounting information for expenditure control. Accounting information is only useful for control if it is timely, accurate, and complete. In Nigeria, there are persistent issues with the timeliness of financial reporting (MDAs submit reports late), the accuracy of data (errors in data entry, classification errors, reconciling items), and completeness (some expenditures are not recorded, or are recorded in suspense accounts). The CBN, as banker to the government, has accurate information about payments made, but this information may not match MDA records due to timing differences or errors. The problem is that if accounting information is not reliable, expenditure control is compromised, and the CBN’s role in providing information for oversight is diminished (Accountant-General, 2018; Auditor-General, 2018; World Bank, 2010).

1.3 Aim of the Study

The specific aim of this research work is to critically examine the role of accounting in the control of public expenditure in Nigeria, using the Central Bank of Nigeria (CBN) as a case study, with a particular focus on assessing the effectiveness of the CBN’s role in payment processing, cash management, and financial reporting for expenditure control; identifying the accounting-related weaknesses that undermine expenditure control; and developing recommendations for strengthening the role of accounting in public expenditure control.

1.4 Objectives of the Study

1. To examine the role of the Central Bank of Nigeria (CBN) in the control of public expenditure, including its functions as banker to the government (TSA), payment processor, and provider of accounting and reporting services.

2. To assess the effectiveness of the Government Integrated Financial Management Information System (GIFMIS), the Treasury Single Account (TSA), and the Integrated Payroll and Personnel Information System (IPPIS) in controlling public expenditure.

3. To identify the accounting-related weaknesses and gaps that undermine effective public expenditure control in Nigeria, including issues in authorisation, documentation, recording, reporting, and reconciliation.

4. To evaluate the quality of accounting information (timeliness, accuracy, completeness) used for expenditure control in Nigeria and its impact on decision-making by oversight bodies.

5. To develop recommendations for strengthening the role of accounting in public expenditure control in Nigeria, including improvements to accounting systems, processes, controls, and coordination among the CBN, Accountant-General, and MDAs.

1.5 Research Questions

1. What is the role of the Central Bank of Nigeria (CBN) in the control of public expenditure, and how does the CBN perform its functions as banker to the government, payment processor, and provider of accounting services?

2. How effective are the Government Integrated Financial Management Information System (GIFMIS), the Treasury Single Account (TSA), and the Integrated Payroll and Personnel Information System (IPPIS) in controlling public expenditure in Nigeria?

3. What accounting-related weaknesses (authorisation, documentation, recording, reporting, reconciliation) undermine effective public expenditure control in Nigeria?

4. How reliable (timely, accurate, complete) is the accounting information used for expenditure control in Nigeria, and how does information quality affect decision-making by oversight bodies?

5. What recommendations can be developed to strengthen the role of accounting in public expenditure control in Nigeria, including improvements to accounting systems, processes, controls, and coordination mechanisms?

1.6 Research Hypotheses

Hypothesis 1

H0₁: The Central Bank of Nigeria’s role as banker to the government (TSA operations, payment processing) has no significant effect on the control of public expenditure in Nigeria.

H1₁: The Central Bank of Nigeria’s role as banker to the government (TSA operations, payment processing) has a significant effect on the control of public expenditure in Nigeria.

Hypothesis 2

H0₂: The Government Integrated Financial Management Information System (GIFMIS) has no significant effect on the effectiveness of public expenditure control in Nigeria.

H1₂: The Government Integrated Financial Management Information System (GIFMIS) has a significant effect on the effectiveness of public expenditure control in Nigeria.

Hypothesis 3

H0₃: The Treasury Single Account (TSA) has no significant effect on the control of public expenditure in Nigeria.

H1₃: The Treasury Single Account (TSA) has a significant effect on the control of public expenditure in Nigeria.

Hypothesis 4

H0₄: The quality of accounting information (timeliness, accuracy, completeness) has no significant effect on the effectiveness of public expenditure control in Nigeria.

H1₄: The quality of accounting information (timeliness, accuracy, completeness) has a significant effect on the effectiveness of public expenditure control in Nigeria.

Hypothesis 5

H0₅: There is no significant relationship between accounting weaknesses (authorisation, documentation, recording, reporting, reconciliation) and the incidence of expenditure irregularities in Nigeria.

H1₅: There is a significant relationship between accounting weaknesses (authorisation, documentation, recording, reporting, reconciliation) and the incidence of expenditure irregularities in Nigeria.

1.7 Justification of the Study

This study is justified by the critical importance of effective public expenditure control for fiscal discipline, macroeconomic stability, and service delivery in Nigeria. Public expenditure accounts for a significant proportion of GDP (approximately 20-25% of GDP in recent years), and any inefficiency or leakage imposes substantial costs on the Nigerian people. The Auditor-General’s reports consistently identify billions of naira in irregularities, representing resources that could have been used for schools, hospitals, roads, and other public services. Understanding the role of accounting—and specifically the role of the Central Bank of Nigeria—in controlling public expenditure is essential for identifying weaknesses and developing reforms. The study is further justified by the limited empirical research on the effectiveness of Nigeria’s public financial management reforms, particularly the role of the CBN in expenditure control. Most existing studies have focused on the policy framework or the role of the Accountant-General’s office, with limited attention to the CBN’s contributions and limitations. This study addresses this gap by providing a focused case study of the CBN’s role (Okonjo-Iweala, 2012; Auditor-General, 2018; World Bank, 2010).

1.8 Significance of the Study

This study makes significant contributions to multiple stakeholder groups with interests in public expenditure control in Nigeria. For the Central Bank of Nigeria (CBN), the study provides empirical evidence on the effectiveness of its role in expenditure control and identifies areas for improvement in payment processing, cash management, and financial reporting. For the Office of the Accountant-General of the Federation, the study provides insights into the integration of GIFMIS, TSA, and IPPIS, and identifies weaknesses in accounting information quality. For the Auditor-General of the Federation, the study provides evidence on the root causes of expenditure irregularities, informing audit planning and recommendations. For the Ministry of Finance, the study provides evidence to inform policy and reform priorities. For the National Assembly and Public Accounts Committee, the study provides an evidence base for oversight and legislative action. For international development partners (IMF, World Bank), the study provides country-specific evidence to inform technical assistance and policy advice. For academic researchers, the study contributes to the literature on public financial management in developing economies, testing and extending theories of expenditure control in the Nigerian context (Okonjo-Iweala, 2012; World Bank, 2010; Auditor-General, 2018).

1.9 Scope of the Study

The scope of this study is delimited to an examination of the role of accounting in the control of public expenditure in Nigeria, using the Central Bank of Nigeria (CBN) as a case study. The study focuses specifically on the CBN’s roles as banker to the government (Treasury Single Account operations), payment processor, and provider of accounting and reporting services for government expenditure. The study examines the effectiveness of the Government Integrated Financial Management Information System (GIFMIS), the Treasury Single Account (TSA), and the Integrated Payroll and Personnel Information System (IPPIS) from the perspective of expenditure control. The study includes the period from 2010 to 2020 (or the most recent available data), capturing the implementation of major public financial management reforms. The study does not include other agencies involved in expenditure control (Accountant-General, Budget Office, Ministry of Finance, Auditor-General) except as they interact with the CBN. The study does not include revenue management (tax collection, oil revenues) except as revenue affects expenditure. The study does not include state and local government expenditure control; it focuses on federal government expenditure. The study does not include procurement oversight (Bureau of Public Procurement) except as it relates to payment processing.

1.10 Definition of Terms

Public Expenditure Control: The systems, processes, and institutions that ensure that government spending is authorised by law, within appropriated amounts, used for intended purposes, properly documented, accurately recorded, and transparently reported (Premchand, 1993; IMF, 2001).

Accounting: The systematic process of identifying, measuring, recording, classifying, summarising, and reporting financial transactions to provide information for decision-making, control, and accountability (Lienert, 2003).

Central Bank of Nigeria (CBN) : The apex financial institution and banker to the Federal Government of Nigeria, responsible for maintaining the Consolidated Revenue Fund accounts, operating the Treasury Single Account, processing government payments, and providing accounting and reporting services for government expenditure (CBN, 1991).

Treasury Single Account (TSA) : A government bank account (or set of linked accounts) at the central bank that consolidates all government funds, enabling better cash management and expenditure control by centralising payments and preventing off-budget accounts (Okonjo-Iweala, 2012; CBN, 2015).

Government Integrated Financial Management Information System (GIFMIS) : An information technology system that integrates budget formulation, budget execution, accounting, reporting, and cash management for the Federal Government of Nigeria, automating controls and providing real-time information (Accountant-General, 2018; World Bank, 2010).

Integrated Payroll and Personnel Information System (IPPIS) : An information system that integrates payroll and personnel data for Federal Government employees, enabling verification of employee existence and eligibility, and preventing ghost workers and payroll fraud (Okonjo-Iweala, 2012; Accountant-General, 2018).

Consolidated Revenue Fund (CRF) : The main government bank account (operated by the CBN) into which all government revenues must be paid and from which expenditures must be authorised, as established by the Constitution (Federal Republic of Nigeria, 1999).

Appropriation: Legal authorisation from the National Assembly (through the Appropriation Act) for the government to spend a specified amount of money for a specified purpose within a specified period (Federal Republic of Nigeria, 1999).

Commitment Accounting: An accounting system that records future obligations (commitments) when contracts are signed or purchase orders issued, reserving funds so that expenditures do not exceed appropriations (Premchand, 1993).

Variance Analysis: The process of comparing actual expenditures to budgeted amounts, calculating differences (variances), and investigating causes for management control and corrective action (Premchand, 1993).

Bank Reconciliation: The process of comparing the government’s accounting records (maintained by MDAs and Accountant-General) with the CBN’s records of payments and receipts, identifying and explaining differences (discrepancies) (CBN, 2015).

Ghost Worker: A person who is not a legitimate employee of the government but who appears on the payroll, enabling fraudulent payment of salaries (Okonjo-Iweala, 2012).

Off-Budget Account: A bank account maintained by an MDA outside the Treasury Single Account, not subject to central expenditure control, creating a risk of unauthorised spending and fraud (Okonjo-Iweala, 2012).

CHAPTER TWO: LITERATURE REVIEW

2.1 Theoretical Review

The theoretical foundation for examining the role of accounting in the control of public expenditure in Nigeria draws from multiple theoretical perspectives in public finance, accounting, public administration, and political economy. This section critically reviews the principal theories informing understanding of public expenditure control, including the classical public expenditure theory, the principal-agent theory, the stewardship theory, the public choice theory, the institutional theory of public financial management, and the normative public expenditure control framework.

2.1.1 Classical Public Expenditure Theory

Classical public expenditure theory, rooted in the works of Adam Smith (1776), John Stuart Mill (1848), and other classical economists, provides the foundational framework for understanding the role and limits of public expenditure. The classical view emphasised that government expenditure should be limited to the essential functions of the state: defence, justice, and public works (infrastructure). Classical economists argued that public expenditure should be kept to a minimum because government spending is inherently less efficient than private spending (due to lack of market discipline, bureaucracy, and political interference). The classical theory also established the principle of legality: public expenditure must be authorised by law (appropriation) and must comply with legal requirements. This principle remains a cornerstone of modern public expenditure control (Smith, 1776; Mill, 1848; Musgrave and Musgrave, 2004).

The classical public expenditure theory has important implications for accounting and expenditure control. If public expenditure is to be kept to a minimum and strictly controlled, then accounting systems must provide accurate, timely information about expenditures, must ensure that expenditures do not exceed appropriations, and must detect and prevent irregularities. The classical emphasis on legality translates into accounting controls that verify that expenditures are properly authorised, that supporting documentation is complete, and that appropriations are not exceeded. The classical distrust of government also implies the need for independent external audit to provide assurance that public funds have been used as intended. The Nigerian public expenditure control framework, with its emphasis on appropriation, budget control, and audit, reflects classical principles (Musgrave and Musgrave, 2004; Premchand, 1993; Khan and Hildreth, 2002).

The classical theory has been criticised for underestimating the role of government in economic development (e.g., provision of public goods, correction of externalities, redistribution) and for overestimating the inefficiency of public spending. Modern public expenditure theory recognises that government spending can be productive and that well-designed expenditure control systems can be efficient. However, the classical principles of legality, budget control, and audit remain central to public expenditure control in Nigeria and other countries (Keynes, 1936; Musgrave, 1959; IMF, 2001).

The application of classical public expenditure theory to the Nigerian context must consider the evolution of the Nigerian state’s role in the economy. Nigeria is a developing country with significant infrastructure deficits, poverty, and inequality, requiring substantial public investment. The classical prescription of minimal government may be inappropriate for Nigeria’s development needs. However, the classical emphasis on expenditure control (preventing waste, fraud, and inefficiency) remains relevant. The challenge is to balance the need for public investment with the need for effective expenditure control (Okonjo-Iweala, 2012; World Bank, 2010; Soludo, 2003).

2.1.2 Principal-Agent Theory

Principal-agent theory, as developed by Jensen and Meckling (1976) and others, provides a powerful framework for understanding the relationship between citizens (principals), government officials (agents), and the role of accounting and auditing in controlling public expenditure. In the public sector context, citizens are the ultimate principals; they delegate authority to elected officials (politicians) and appointed officials (bureaucrats) to manage public resources. This delegation creates agency problems: information asymmetry (agents have more information about their actions and the use of public funds than principals) and diverging interests (agents may pursue their own interests—power, prestige, personal wealth—at the expense of citizens). Public expenditure control mechanisms, including accounting, internal controls, and external audit, are designed to reduce these agency problems (Jensen and Meckling, 1976; Eisenhardt, 1989; Baiman, 1990).

Principal-agent theory explains why accounting is essential for public expenditure control. Accounting provides information that reduces information asymmetry: citizens and their representatives (legislators) can see how funds were spent, whether they were spent as intended, and whether they achieved results. Accounting also provides a basis for monitoring and enforcing contracts (the social contract between citizens and government). Without reliable accounting information, citizens cannot hold government accountable for the use of public funds. The theory predicts that when accounting information is incomplete, inaccurate, or untimely, agency problems will be more severe (waste, fraud, corruption, inefficiency). The Nigerian experience, with persistent audit queries and expenditure irregularities, is consistent with this prediction (Baiman, 1990; Jensen and Meckling, 1976; Okonjo-Iweala, 2012).

Principal-agent theory also explains the role of the Central Bank of Nigeria as an agent of the government and the citizens. The CBN is entrusted with managing government bank accounts (TSA), processing payments, and providing accounting information. The CBN is an agent of the government (the principal), but the government itself is an agent of the citizens. This creates a chain of agency relationships: citizens → government → CBN. The CBN’s performance as an agent depends on the incentives and oversight it faces. If the CBN is not adequately monitored (by the Ministry of Finance, the National Assembly, the Auditor-General), or if its incentives are misaligned, it may not perform effectively. The theory suggests that strengthening oversight of the CBN and aligning its incentives with public interest is essential for effective expenditure control (Macey and O’Hara, 2003; Jensen, 1993).

The application of principal-agent theory to the Nigerian public expenditure control system suggests several reform priorities. First, accounting systems (GIFMIS, TSA, IPPIS) should provide timely, accurate, and complete information to reduce information asymmetry. Second, audit systems (internal audit, external audit by the Auditor-General) should monitor agent behaviour and report to principals (citizens and their representatives). Third, consequences for poor performance (sanctions for irregular expenditures, prosecution for fraud) should be credible and enforced. Fourth, the chain of agency relationships should be transparent, with clear accountability for each agent. The Nigerian public financial management reforms (GIFMIS, TSA, IPPIS) are consistent with these principles, but implementation has been incomplete (Okonjo-Iweala, 2012; World Bank, 2010; Auditor-General, 2018).

2.1.3 Stewardship Theory

Stewardship theory, developed by Davis, Schoorman, and Donaldson (1997), presents a contrasting view to agency theory by arguing that public officials (agents) are inherently motivated to act in the best interests of citizens (principals), rather than pursuing self-interested behaviour. The theory posits that officials derive satisfaction from organisational achievement, public service, and professional recognition, and that their interests can be aligned with those of citizens through trust, empowerment, and intrinsic motivation rather than through extensive monitoring and control mechanisms. In the public expenditure context, stewardship theory suggests that government officials and CBN employees are professionals who have internalised norms of public service, fiduciary responsibility, and accountability, and who will manage public funds responsibly even in the absence of intensive monitoring (Davis, Schoorman, and Donaldson, 1997; Donaldson and Davis, 1991; Muth and Donaldson, 1998).

Stewardship theory has important implications for the design of public expenditure control systems. If officials are stewards, excessive controls may be counterproductive, undermining their intrinsic motivation, creating resentment, and encouraging a compliance mentality rather than a commitment to public service. The theory suggests that expenditure control systems should be designed to support and enable responsible stewardship, not just to constrain and monitor. This implies the need for clear guidance, training, and support for officials, as well as accountability for outcomes (not just compliance). The Nigerian public financial management reforms, including GIFMIS and TSA, have elements of both monitoring (agency) and enabling (stewardship) (Davis et al., 1997; Lienert, 2003; Premchand, 1993).

The application of stewardship theory to the Central Bank of Nigeria suggests that CBN employees are likely motivated by professionalism and public service. The CBN has a reputation for technical competence, and many CBN staff are professionally qualified (economists, accountants, bankers). Stewardship theory predicts that these professionals will act responsibly in managing government accounts and processing payments, even without intensive oversight. However, the theory also recognises that stewardship can be undermined by poor organisational culture, inadequate resources, or perverse incentives. In Nigeria, there have been allegations of corruption within the CBN (e.g., fraudulent payments processed with insider collusion), suggesting that stewardship cannot be assumed; both agency and stewardship perspectives are relevant (Okonjo-Iweala, 2012; CBN, 2015; Auditor-General, 2018).

The complementarity between agency theory and stewardship theory is important for understanding public expenditure control. A hybrid approach is appropriate: baseline controls (segregation of duties, authorisation, documentation, reconciliation) for all officials, with more intensive oversight for areas where risks are higher. The Nigerian public financial management system incorporates both elements: mandatory controls (e.g., GIFMIS preventing payments exceeding appropriations) and trust-based elements (e.g., delegation of expenditure authority to MDAs). The effectiveness of the hybrid approach depends on the quality of the control environment and the integrity of officials (Sundaramurthy and Lewis, 2003; Lane, 2011; Okonjo-Iweala, 2012).

2.1.4 Public Choice Theory

Public choice theory, developed by Buchanan and Tullock (1962), Niskanen (1971), and others, applies economic analysis to political and bureaucratic behaviour. The theory assumes that politicians, bureaucrats, and other public officials are self-interested actors who maximise their own utility (power, budget, prestige, job security) rather than the public interest. Public choice theory predicts that bureaucrats (including officials in the CBN and MDAs) will seek to maximise their budgets (Niskanen’s budget-maximising bureaucrat model), will resist transparency and accountability, and will engage in rent-seeking activities. The theory explains why expenditure control is difficult: officials have incentives to spend more, to hide spending, and to resist controls (Buchanan and Tullock, 1962; Niskanen, 1971; Mueller, 2003).

Public choice theory has important implications for public expenditure control. If officials are budget-maximising and self-interested, then control mechanisms must be external and coercive, not reliant on self-restraint or professional ethics. Accounting controls (such as GIFMIS) must be automated and enforced by central agencies (Accountant-General, Ministry of Finance, CBN) to prevent officials from circumventing controls. Transparency (publication of expenditure data) is essential to enable citizens and civil society to monitor spending. Competition among agencies and outsourcing of functions can reduce the monopoly power of bureaucrats. The Nigerian public financial management reforms (GIFMIS, TSA, IPPIS) are consistent with public choice theory: they automate controls, centralise cash management, and increase transparency (Niskanen, 1971; Mueller, 2003; World Bank, 2010).

Public choice theory also explains the difficulty of implementing and sustaining expenditure control reforms. Politicians and bureaucrats who benefit from weak controls (e.g., access to off-budget accounts, ability to award inflated contracts, opportunities for corruption) will resist reforms. The Nigerian experience with public financial management reforms has included resistance from MDAs that did not want to consolidate their accounts into the TSA or integrate their payroll into IPPIS. Overcoming this resistance requires political will at the highest levels (the Presidency), support from international development partners, and sometimes coercive measures (e.g., blocking payments from non-TSA accounts). The success of Nigeria’s reforms is attributed in part to the strong political will of the Obasanjo and Jonathan administrations (Okonjo-Iweala, 2012; World Bank, 2010; CBN, 2015).

The application of public choice theory to the Central Bank of Nigeria suggests that the CBN, as a bureaucracy, may also have incentives to expand its role, budget, and influence. The CBN’s role in expenditure control (TSA, payment processing) gives it significant power over MDAs. There may be risks of the CBN using this power to benefit itself (e.g., maintaining high cash balances in TSA to earn seigniorage or investment income) or to favour certain MDAs. Public choice theory suggests that the CBN should be subject to oversight (by the Ministry of Finance, the National Assembly, the Auditor-General) to ensure that it performs its expenditure control functions in the public interest, not its own interest (Mueller, 2003; Okonjo-Iweala, 2012).

2.1.5 Institutional Theory of Public Financial Management

The institutional theory of public financial management, developed by Lienert (2003), Diamond (2006), and the International Monetary Fund (IMF, 2001), provides a framework for understanding the institutional arrangements, processes, and systems necessary for effective public expenditure control. The theory emphasises that public financial management is not just about accounting techniques; it is about the institutions (laws, regulations, organisations, procedures, culture) that shape fiscal behaviour. Effective expenditure control requires a coherent institutional framework: clear legal authority for spending (appropriation), separation of responsibilities (execution, accounting, oversight), robust information systems (budget execution, accounting, reporting), skilled personnel (competent accountants and auditors), and accountability mechanisms (internal audit, external audit, legislative oversight). The theory also recognises that institutions must be adapted to country-specific circumstances (Lienert, 2003; Diamond, 2006; IMF, 2001).

The institutional theory of public financial management has important implications for the role of accounting in expenditure control. Accounting is not an end in itself but a means to support the institutional framework. Accounting systems (GIFMIS) must be designed to meet the information needs of budget managers, accountants, auditors, legislators, and the public. Accounting rules (classification, chart of accounts) must be consistent with the budget classification to enable comparison of actual and budgeted expenditures. Accounting processes (commitment accounting, payment processing) must be integrated with budget execution controls. Accounting reports (budget execution reports, financial statements) must be timely, accurate, and accessible. The theory emphasises that accounting reforms must be part of a broader institutional reform programme, not implemented in isolation (Lienert, 2003; Diamond, 2006; World Bank, 2010).

The Nigerian public financial management reforms (GIFMIS, TSA, IPPIS) are consistent with institutional theory. The reforms aim to strengthen the institutional framework for expenditure control by automating processes, centralising cash management, and integrating payroll and personnel data. However, institutional theory also recognises that formal institutions (laws, systems) may differ from informal institutions (actual practices, culture). In Nigeria, there is a gap between formal rules (e.g., appropriations must not be exceeded) and actual practices (supplementary budgets, virements, unauthorised expenditures). The Auditor-General’s reports identify persistent non-compliance, indicating that the formal institutional framework is not fully effective. Closing the gap between formal and informal institutions requires not just systems but also enforcement, capacity building, and cultural change (Lienert, 2003; Diamond, 2006; Auditor-General, 2018).

The application of institutional theory to the Central Bank of Nigeria suggests that the CBN’s role in expenditure control must be understood within the broader institutional framework. The CBN is one institution among many (Accountant-General, Ministry of Finance, MDAs, Auditor-General, National Assembly). The effectiveness of the CBN in expenditure control depends on the effectiveness of these other institutions. If MDAs do not properly authorise payments, the CBN may process improper payments. If the Accountant-General does not enforce budget controls in GIFMIS, the CBN may receive payment instructions that violate appropriations. If the Auditor-General does not audit effectively, problems may not be detected or corrected. The CBN cannot compensate for weaknesses in other institutions; institutional reform must be comprehensive (Lienert, 2003; Diamond, 2006; Okonjo-Iweala, 2012).

2.1.6 Normative Public Expenditure Control Framework

The normative public expenditure control framework, articulated by the International Monetary Fund (IMF, 2001), the World Bank (1998), and the Public Expenditure and Financial Accountability (PEFA) framework, provides a set of principles and standards for effective public expenditure control. The framework identifies several key principles: legality (expenditure must be authorised by law); budgetary control (expenditure must not exceed appropriations); regularity (expenditure must comply with regulations); propriety (expenditure must be ethical and prudent); value for money (expenditure must be economic, efficient, and effective); and accountability (officials must be answerable for their use of public funds). The framework also identifies key elements of an effective expenditure control system: a budget classification that supports control; commitment control (reserving funds for future obligations); payment control (verifying authorisation and documentation); accounting and reporting (recording and reporting expenditures); and audit (independent verification) (IMF, 2001; World Bank, 1998; PEFA, 2016).

The normative framework provides a benchmark against which Nigeria’s expenditure control system can be assessed. Nigeria has made significant progress in adopting normative principles: the Constitution establishes legality; the Appropriation Act establishes budgetary control; the Financial Regulations establish regularity and propriety; the Public Procurement Act addresses value for money; and the Auditor-General provides independent assurance. However, implementation gaps remain: unauthorised expenditures (legality not observed); expenditures exceeding appropriations (budgetary control weak); unsupported payments (regularity not observed); procurement irregularities (value for money compromised); and weak follow-up on audit recommendations (accountability weak). The normative framework identifies where Nigeria’s system falls short and what improvements are needed (Okonjo-Iweala, 2012; Auditor-General, 2018; PEFA, 2016).

The normative framework also addresses the role of accounting in expenditure control. Accounting should provide: a clear trail from budget to commitment to payment to report; timely information on budget execution (actual expenditures compared to budget); accurate classification of expenditures (economic, administrative, functional); and reliable data for audit. The Nigerian GIFMIS is designed to provide these features, but issues with data timeliness, accuracy, and completeness remain. The normative framework suggests that accounting systems should be subject to independent quality assurance and that users (MDAs, Accountant-General, CBN) should be trained in their use. The framework also suggests that accounting information should be publicly available to enhance transparency and accountability (PEFA, 2016; IMF, 2001; World Bank, 2010).

The application of the normative framework to the Central Bank of Nigeria suggests that the CBN should be evaluated against these principles. Does the CBN ensure that payments are authorised by law (legality)? Does it ensure that payments do not exceed appropriations (budgetary control)? Does it ensure that payments are properly supported (regularity)? Does it report expenditures accurately and timely (accounting)? The evidence suggests that the CBN is largely compliant but cannot compensate for weaknesses in other agencies. The normative framework suggests that the CBN’s role should be clarified (it is responsible for processing payments, not verifying underlying legitimacy), and that payment controls should be strengthened (e.g., requiring digital signatures, two-factor authentication) (Okonjo-Iweala, 2012; CBN, 2015; Auditor-General, 2018).

2.2 Conceptual Framework

The conceptual framework for this study specifies the relationship between accounting functions (independent variables) and public expenditure control (dependent variable), with the Central Bank of Nigeria playing a mediating role. The framework identifies the key accounting functions relevant to expenditure control, the dimensions of expenditure control, and the moderating variables that affect the relationship.

2.2.1 Independent Variables: Accounting Functions

The first independent variable is budgeting and appropriation control, defined as the accounting processes that ensure that expenditures are within appropriated amounts and for approved purposes. Key dimensions include: recording of appropriations in the accounting system (GIFMIS); commitment accounting (recording obligations when contracts are signed or purchase orders issued, reserving funds); pre-audit of payments (verifying that goods/services have been received, that the expenditure is within appropriation, and that documentation is complete); and budget reporting (regular reports comparing actual expenditures to budget). The CBN processes payments based on appropriation information from GIFMIS; if appropriations are not properly recorded or enforced, expenditure control is compromised (Premchand, 1993; Lienert, 2003; PEFA, 2016).

The second independent variable is cash management and payment processing, defined as the accounting processes that ensure that payments are properly authorised, supported, and recorded, and that cash resources are managed efficiently. Key dimensions include: maintenance of the Treasury Single Account (TSA) at the CBN; verification of payment authorisations (digital signatures, approval codes); review of supporting documentation (invoices, delivery notes, contracts); processing of payments (ensuring payee is correct, amount is correct, account is correct); and bank reconciliations (comparing CBN records to MDA records). The CBN is the central actor in cash management and payment processing; its effectiveness directly affects expenditure control (Okonjo-Iweala, 2012; CBN, 2015; Diamond, 2006).

The third independent variable is accounting and reporting, defined as the processes that record, classify, summarise, and report expenditure transactions. Key dimensions include: classification of expenditures (by economic category, administrative unit, programme/activity); timeliness of recording (transactions recorded promptly); accuracy of recording (transactions recorded correctly, with correct amounts and classifications); and reporting (production of budget execution reports, financial statements, and other reports for management and oversight). The CBN provides accounting information to the Accountant-General (who consolidates government accounts) and to the Auditor-General (for audit). The quality of accounting information affects the ability of oversight bodies to monitor expenditure control (Premchand, 1993; Khan and Hildreth, 2002; Lienert, 2003).

The fourth independent variable is internal control and audit, defined as the systems and processes that prevent, detect, and correct errors, irregularities, and fraud. Key dimensions include: segregation of duties (different individuals responsible for authorising, processing, recording, and reconciling payments); authorisation controls (requirements for approval of expenditures); documentation controls (requirements for supporting documentation); physical controls (security of cash, cheques, payment systems); and internal audit (independent review of controls and transactions). The CBN has its own internal control and internal audit functions; these affect the CBN’s ability to process payments without error or fraud. The CBN also relies on internal controls in MDAs and the Accountant-General’s office (COSO, 2013; IFAC, 2001; Auditor-General, 2018).

2.2.2 Mediating Variable: Central Bank of Nigeria

The Central Bank of Nigeria (CBN) mediates the relationship between accounting functions and public expenditure control. The CBN performs three key functions: banker to the government (maintaining the TSA), payment processor (authorising and releasing payments), and provider of accounting information (bank reconciliations, financial reports). The effectiveness of the CBN in performing these functions affects the overall effectiveness of expenditure control. If the CBN performs well, it can compensate for weaknesses in other agencies (to some extent). If the CBN performs poorly, it can undermine expenditure control even if other agencies perform well (Okonjo-Iweala, 2012; CBN, 2015; World Bank, 2010).

2.2.3 Dependent Variable: Public Expenditure Control

The dependent variable is public expenditure control, defined as the effectiveness of the system in ensuring that public funds are spent as authorised by law, within appropriated amounts, for intended purposes, properly documented, accurately recorded, and transparently reported. Public expenditure control is measured across five dimensions: legality (expenditures are authorised by law); budgetary control (expenditures do not exceed appropriations); regularity (expenditures are properly supported and comply with regulations); propriety (expenditures are ethical and prudent); and accountability (officials are answerable for their use of public funds). Indicators include: incidence of unauthorised expenditures (from Auditor-General’s report); incidence of expenditures exceeding appropriations; incidence of unsupported payments; procurement irregularities; and follow-up on audit recommendations (IMF, 2001; PEFA, 2016; Auditor-General, 2018).

2.2.4 Moderating Variables

The relationship between accounting functions, the CBN’s mediating role, and public expenditure control is moderated by several variables. The quality of accounting systems (GIFMIS, TSA, IPPIS) affects the ability to record, process, and report expenditures accurately and timely. The competence of accounting personnel (in MDAs, Accountant-General, CBN) affects the quality of data entry, classification, and reporting. The integrity of officials (freedom from corruption) affects the likelihood that controls will be circumvented. The political environment (political will for fiscal discipline, electoral cycles) affects the enforcement of controls. The legal framework (appropriation law, procurement law, fiscal responsibility law) sets the rules, but enforcement depends on other factors. The oversight environment (effectiveness of National Assembly, Auditor-General, civil society) affects the consequences of non-compliance (Lienert, 2003; Diamond, 2006; Okonjo-Iweala, 2012).

2.2.5 Representation of the Conceptual Framework

The conceptual framework can be represented as follows:

Independent Variables (Accounting Functions)

• Budgeting and appropriation control
• Cash management and payment processing
• Accounting and reporting
• Internal control and audit

Mediating Variable

• Central Bank of Nigeria (TSA, payment processing, accounting)

Moderating Variables

• Accounting system quality (GIFMIS, TSA, IPPIS)
• Personnel competence and integrity
• Political environment
• Legal framework
• Oversight effectiveness

Dependent Variable

• Public expenditure control (legality, budgetary control, regularity, propriety, accountability)

The framework guides the empirical investigation of the role of accounting in the control of public expenditure in Nigeria, with a focus on the Central Bank of Nigeria as a case study.

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
Smith (1776); Mill (1848)	Developed classical public expenditure theory; established principles of legality, budget control, limited government	Classical principles may be too restrictive for developing economies requiring public investment	Theoretical development in European context; applicability to developing economies debated	Application to Nigerian public expenditure control not examined; classical principles vs. development needs not balanced
Jensen and Meckling (1976)	Developed principal-agent theory; explains information asymmetry and need for monitoring	Assumes rational self-interest; limited attention to ethical or trust-based governance	Theoretical framework with extensive testing in corporate context; public sector testing more limited	Application to Nigerian public expenditure control not examined; agency problems in CBN-government relationship not analysed
Davis, Schoorman and Donaldson (1997)	Developed stewardship theory; alternative to agency; emphasises trust and empowerment	May overstate altruism of public officials; limited empirical evidence in developing economies	Theoretical framework with limited testing in public sector; Nigerian context not examined	Application to Nigerian public officials not examined; stewardship vs. agency assumptions in Nigeria not tested
Buchanan and Tullock (1962); Niskanen (1971)	Developed public choice theory; explains bureaucratic self-interest and budget maximisation	Assumes officials are purely self-interested; may be overly pessimistic	Theoretical framework with empirical testing primarily in Western contexts	Application to Nigerian bureaucrats not examined; budget-maximising behaviour in Nigerian MDAs not tested
Lienert (2003); Diamond (2006)	Developed institutional theory of PFM; emphasises coherent institutional framework	Focus on formal institutions; informal institutions (culture, practices) equally important	Theoretical framework with case studies; not Nigeria-specific	Application to Nigerian PFM institutions not examined; gap between formal and informal institutions not analysed
IMF (2001); PEFA (2016)	Developed normative expenditure control framework; provides benchmarks and indicators	Normative framework may not account for country-specific constraints	International standards with limited country-specific adaptation	Application to Nigeria not systematically assessed; PEFA scores for Nigeria not analysed
Okonjo-Iweala (2012)	Insider account of Nigerian PFM reforms; detailed analysis of GIFMIS, TSA, IPPIS	Reflects author’s perspective; may understate implementation problems	Case study memoir with limited comparative perspective	Independent evaluation of reforms not provided; role of CBN in expenditure control not systematically analysed
Auditor-General (2018)	Official audit reports; primary source on expenditure irregularities	Reports may not capture all irregularities; lag between audit period and report publication	Compliance-focused audit; limited analysis of root causes	Link between accounting weaknesses and irregularities not established; CBN’s role in irregularities not analysed
World Bank (2010)	Comprehensive PFM review of Nigeria; identifies strengths and weaknesses	Now somewhat dated (2010); post-2010 reforms not covered	Diagnostic study with recommendations; limited primary data	Post-2010 effectiveness of reforms not assessed; CBN’s evolving role not captured
CBN (2015)	Official CBN annual report; provides data on TSA, payment processing	Official report may reflect reporting biases; limited detail on expenditure control challenges	Single-year report; limited trend analysis	CBN’s role in expenditure control over time not analysed; challenges and failures not fully disclosed
Premchand (1993)	Comprehensive text on public expenditure management; foundational for PFM	Now dated (1993); pre-digital era; less relevant for automated systems	Textbook synthesis with examples primarily from developed economies	Application to automated systems (GIFMIS) not covered; Nigerian context not addressed
Lienert (2003)	Comparative analysis of PFM reforms in developing countries; identifies success factors	Cross-country analysis may not capture Nigeria-specific factors	Comparative study with limited depth on any single country	Nigeria-specific PFM reform effectiveness not analysed; CBN’s role in comparative perspective not examined