Project – The Impact of Inflation on Economic Growth in Nigeria: A Case Study of Nigeria, 2000–2025.

CHAPTER ONE

INTRODUCTION

1.1 Background of the Study

Economic growth is one of the central objectives of macroeconomic policy because it represents an expansion in the productive capacity and real output of an economy over time. Sustained economic growth is generally associated with increased employment opportunities, improved household incomes, higher government revenue, greater investment and improved standards of living. For developing economies such as Nigeria, achieving stable and sustainable economic growth is particularly important because of the country’s large population, infrastructure requirements, unemployment challenges and need for economic diversification.

Economic growth is commonly measured by changes in real Gross Domestic Product (GDP), which captures the value of goods and services produced within an economy after adjusting for changes in prices. The use of real GDP is particularly important when examining the relationship between inflation and growth because nominal GDP can increase merely because the general price level has risen. The World Bank provides annual GDP growth data for Nigeria based on official national accounts and related international data sources, making it an important source for assessing the country’s growth performance over time.

Inflation, on the other hand, refers to a sustained increase in the general price level of goods and services in an economy over a period of time. It is normally measured using a consumer price index or another broad price index. When inflation rises, the purchasing power of money declines, meaning that consumers need more money to purchase the same quantity of goods and services. The World Bank’s inflation series for Nigeria, sourced from the International Financial Statistics database of the International Monetary Fund (IMF), provides annual consumer-price inflation data extending through 2025.

The relationship between inflation and economic growth has long been debated in macroeconomic literature. At low and moderate levels, inflation may coexist with economic expansion and can sometimes accompany increased demand and production. However, persistent and high inflation can create uncertainty, distort relative prices, discourage savings and investment, increase production costs and undermine economic efficiency. Fischer (1993) argues that macroeconomic instability, including high inflation, can negatively affect economic growth through its implications for investment and productivity.

The theoretical relationship between inflation and economic growth is not necessarily linear. Classical and neoclassical perspectives generally associate high and unstable inflation with distortions in resource allocation and lower economic efficiency. Keynesian perspectives, however, suggest that some increase in prices may accompany increased aggregate demand and output, particularly when an economy has underutilised resources. The Phillips Curve also provides a framework for considering a short-run relationship between inflation and economic activity, although the long-run implications of inflation are more complicated.

The quantity theory of money provides another perspective. Under this framework, excessive monetary expansion relative to the growth of real output can generate sustained increases in the general price level. When money supply grows substantially faster than the productive capacity of the economy, inflationary pressures may emerge. However, inflation in a modern economy may result from multiple factors, including monetary conditions, exchange-rate movements, supply constraints, fiscal conditions, expectations, food prices and international commodity prices.

The importance of inflation to economic growth has been demonstrated in several international studies. Barro (1995), using cross-country data, found evidence that higher inflation is associated with lower economic growth and investment. The study suggested that inflation can reduce growth by affecting investment and productivity. Similarly, Khan and Senhadji (2001) examined inflation-growth relationships across industrial and developing countries and found evidence of threshold effects, indicating that inflation may have different effects on growth depending on its level.

Khan and Senhadji’s (2001) findings are particularly important because they challenge the assumption that inflation has the same effect on economic growth at all levels. Their analysis identified threshold levels above which inflation begins to exert a significantly negative effect on growth. This threshold perspective is relevant to Nigeria because the country has frequently experienced inflation rates considerably above those prevailing in many advanced economies.

The Nigerian economy provides a particularly important environment for examining the inflation-growth relationship. Nigeria is Africa’s largest economy and has historically depended heavily on crude-oil exports for foreign-exchange earnings and government revenue. The economy is therefore exposed to fluctuations in international oil prices, exchange-rate movements, fiscal pressures and external shocks. These factors can influence both inflation and economic growth.

Between 2000 and 2025, Nigeria experienced several distinct macroeconomic episodes. The early 2000s were characterised by economic reforms, relatively strong growth and efforts to improve macroeconomic stability. The economy subsequently experienced substantial growth during the 2000s and early 2010s, supported by high oil prices, improved macroeconomic management, increased investment and expansion in several non-oil sectors. However, the economy also experienced periods of substantial inflationary pressure and economic slowdown.

The global financial crisis of 2008–2009 represented an important external shock. Although the Nigerian banking and financial system did not experience the same form of collapse seen in some advanced economies, the fall in global oil prices affected government revenue, foreign exchange availability and economic activity. The episode demonstrated the vulnerability of an oil-dependent economy to global developments.

Nigeria’s inflation-growth relationship became more complicated during the middle of the 2010s. The collapse in global oil prices in 2014–2015 placed significant pressure on Nigeria’s external position and government finances. The resulting foreign-exchange constraints and exchange-rate adjustments contributed to increased inflationary pressure, while the economy entered recession in 2016. This period provides an important illustration of the interaction between inflation, exchange-rate instability, external shocks and economic growth.

Following the 2016 recession, Nigeria returned to positive economic growth, although the pace of expansion remained relatively modest compared with the country’s development requirements. Economic growth was affected by structural constraints including inadequate infrastructure, electricity supply challenges, low productivity, unemployment, insecurity, limited industrial capacity and dependence on oil revenues.

The COVID-19 pandemic created another major disruption in 2020. Restrictions on economic activity, disruptions to international trade, falling global demand and the collapse in oil prices affected Nigeria’s fiscal position and economic performance. Although the economy subsequently recovered, the pandemic contributed to renewed concerns about public finances, employment, supply chains and household welfare.

The period from 2021 to 2025 was particularly significant for Nigeria’s inflation-growth relationship. Global supply-chain disruptions, higher food and energy prices, exchange-rate pressures and domestic structural constraints contributed to rising inflation. The World Bank has documented the continued importance of inflation and macroeconomic stabilisation to Nigeria’s economic performance.

The macroeconomic situation changed substantially following the major reforms introduced from 2023, particularly the removal of the petrol subsidy and significant changes in foreign-exchange market arrangements. These reforms were intended to improve fiscal sustainability, reduce distortions and strengthen the functioning of the economy, but they also generated substantial short-term price pressures. The adjustment in energy prices and exchange-rate conditions increased production and transportation costs, which contributed to higher consumer prices.

The inflationary episode of 2024 was particularly severe. According to the World Bank, Nigeria’s inflation rate was 33.2 percent in 2024. By 2025, inflation had declined substantially, although it remained elevated by international standards. The World Bank reports that inflation declined to approximately 23.0 percent in 2025 while economic growth remained around 4 percent, driven primarily by services and supported by improvements in agriculture and construction.

The Central Bank of Nigeria also reported that domestic inflation declined considerably during 2025. Its monetary policy review states that inflation declined from 34.80 percent in December 2024 to 15.15 percent in December 2025, while GDP growth was 3.98 percent in the third quarter of 2025 compared with 4.23 percent in the second quarter. The CBN attributed the improvement partly to tight monetary policy, exchange-rate stability and improved agricultural production.

These developments demonstrate that the relationship between inflation and economic growth in Nigeria is complex. High inflation does not automatically result in negative GDP growth in every period. Nigeria recorded economic expansion during some periods of elevated inflation, while periods of relatively lower inflation did not always correspond to strong growth. Consequently, it is important to investigate the relationship empirically rather than assume that inflation has an identical effect on economic growth throughout the period.

One of the mechanisms through which inflation can affect growth is investment. Persistent inflation creates uncertainty concerning future costs, revenues and returns. Investors may therefore postpone or reduce long-term investment when they cannot accurately predict future prices. Lower investment can subsequently affect capital formation, productivity and output growth. Fischer (1993) identifies inflation and other macroeconomic instability indicators as important factors in determining investment and economic growth.

Inflation can also affect savings. When the inflation rate exceeds the return on financial assets, the real value of savings declines. Households may consequently reduce their willingness to hold financial savings or shift resources into physical assets that are perceived as better stores of value. Lower financial savings can constrain the funds available for financial intermediation and productive investment.

Interest rates provide another channel through which inflation can influence growth. Central banks commonly respond to persistent inflationary pressures by tightening monetary policy. Higher policy and market interest rates can increase borrowing costs for businesses and households. For firms that depend on credit to finance working capital, machinery and expansion, higher borrowing costs may reduce investment and production.

Inflation can also influence exchange rates. Where domestic inflation is substantially higher than that of trading partners, domestic goods may become less competitive in international markets. At the same time, expectations of further inflation can contribute to currency depreciation and capital-flow pressures. In an import-dependent economy such as Nigeria, exchange-rate depreciation can itself feed back into inflation through higher costs of imported food, machinery, raw materials and petroleum-related products.

The production-cost channel is particularly important in Nigeria. Manufacturers, farmers, transport operators and service providers face changes in the prices of energy, transportation, imported inputs, equipment and other intermediate goods. When these costs increase, firms may raise selling prices, reduce output or postpone expansion. If such pressures persist across sectors, inflation can become both a symptom and a cause of broader economic difficulties.

Inflation can further influence household consumption. When prices rise faster than incomes, real purchasing power falls. Households may reduce consumption of non-essential goods and services and concentrate spending on basic necessities. Since household consumption is an important component of aggregate demand, a substantial decline in real purchasing power can weaken economic activity.

The distributional consequences of inflation also matter. Inflation does not affect all households equally. Low-income households tend to devote a larger share of their income to food, transport, housing and other necessities. Consequently, rapid increases in the prices of essential goods can disproportionately reduce their real welfare. The IMF’s 2025 Article IV assessment of Nigeria noted that inflation remained high while poverty and food insecurity had risen.

Inflation may also affect government finances. Although higher nominal prices can increase nominal tax revenues, inflation can simultaneously raise government expenditure. Public-sector wages, infrastructure costs, social programmes and debt-servicing expenses may increase as prices and interest rates rise. If revenue growth does not keep pace with expenditure pressures, fiscal deficits can become more difficult to manage.

Nigeria’s experience between 2000 and 2025 therefore provides a valuable natural setting for investigating the inflation-growth nexus. The period contains several major economic events, including global financial instability, oil-price shocks, the 2016 recession, the COVID-19 pandemic, post-pandemic inflation, exchange-rate reforms and the 2024–2025 inflation episode. Examining the entire period can provide a broader understanding of whether inflation has systematically influenced Nigeria’s economic growth.

Empirical studies specifically on Nigeria have produced mixed but increasingly important evidence. Omoke (2009), using Nigerian data covering 1970–2005, found no cointegrating relationship between inflation and economic growth over the period examined. This suggests that the relationship may depend on the period, methodology and variables included in the model.

Chude and Chude (2015), examining Nigeria from 2000 to 2009, found a significant relationship between inflation and economic growth. Their study used the Consumer Price Index as a measure of inflation and GDP as a measure of economic growth. The finding is particularly relevant to the present study because it covers the beginning of the period selected for this research.

Doguwa’s study published in the CBN Journal of Applied Statistics provides further evidence of the possibility of nonlinear effects. Using different threshold approaches, Doguwa identified an inflation threshold of 10.5 percent using the Khan and Senhadji methodology, while other approaches suggested thresholds around 11.2 and 12.0 percent. This indicates that inflation may be relatively less damaging below certain levels but may become increasingly harmful once it exceeds a critical threshold.

More recent Nigerian evidence has also supported a negative relationship between high inflation and economic growth. Adaramola and Dada (2020), using an autoregressive distributed lag model and data from 1980–2018, found that inflation and real exchange-rate movements had significant negative effects on economic growth in Nigeria.

Musa and Hussaini (2021) also examined the relationship between inflation and economic growth in Nigeria using an ARDL approach over 1986–2020. Their findings indicated both short-run and long-run relationships and reported a negative effect of inflation on economic growth.

More recently, Bangura and Omojolaibi investigated the Nigerian inflation-growth nexus using data from 1990 to 2021 and an endogenous threshold model. Their findings indicated a nonlinear relationship, with an estimated inflation threshold of 12.88 percent: inflation below that level was associated with a positive effect on growth, while inflation above the threshold had a negative effect.

The continuing debate is therefore not merely whether inflation affects growth but also how much inflation is harmful, through which channels it affects growth, and whether the effect changes over time. This is especially important for Nigeria because the economy has experienced periods of both moderate and exceptionally high inflation.

The 2000–2025 period also provides an opportunity to examine whether the relationship has changed following structural and policy transformations in the Nigerian economy. The economy’s increasing dependence on services, expanding digital economy, changing monetary-policy framework, exchange-rate reforms and evolving fiscal environment may influence how inflation translates into economic growth.

The World Bank’s recent assessment reinforces the importance of this issue. Its 2025 Nigeria Development Update noted that Nigeria made progress in macroeconomic stabilisation, but inflation and living-cost pressures remained significant and the gains from stabilisation had not yet fully translated into improved living standards. The IMF similarly reported that Nigeria continued to face high inflation, poverty and food-security challenges while undertaking significant macroeconomic reforms.

Thus, studying inflation and economic growth over 2000–2025 is relevant not only from an academic perspective but also from a policy perspective. Understanding the relationship can help monetary authorities, fiscal policymakers, investors, businesses and households better understand the consequences of persistent price instability.

It is against this background that this study investigates the impact of inflation on economic growth in Nigeria from 2000 to 2025. The study seeks to establish empirically whether inflation significantly affects economic growth and to provide evidence that can contribute to appropriate macroeconomic policy formulation.

1.2 Statement of the Problem

Nigeria has experienced persistent inflationary pressures for much of the period under consideration. Although the country has recorded periods of strong economic expansion, inflation has remained a recurring macroeconomic challenge. The coexistence of economic growth and relatively high inflation raises an important question concerning the extent to which rising prices affect the country’s real productive performance.

One major problem is the persistent erosion of purchasing power. When prices rise faster than household incomes, consumers are able to purchase fewer goods and services with the same amount of money. This reduces real household welfare and may alter consumption patterns. In a country where a significant proportion of household expenditure is devoted to food and other basic necessities, persistent inflation can have substantial welfare implications.

A second problem is the effect of inflation on private investment. Investors require a relatively predictable macroeconomic environment to make long-term decisions. Persistent inflation makes future costs, expected revenues and real returns more difficult to predict. Consequently, firms may postpone investment decisions, reduce expansion plans or demand higher returns to compensate for inflation risk. Reduced investment can negatively affect capital formation, productivity and economic growth.

A third problem is the effect of inflation on production costs. Nigerian businesses often rely on imported machinery, raw materials, transportation and energy inputs. Inflationary pressures, particularly when accompanied by exchange-rate depreciation, can significantly increase operating costs. Firms may respond by increasing prices, reducing output, reducing their workforce or postponing investment. These responses may weaken aggregate economic activity.

A fourth problem concerns monetary-policy responses to inflation. When inflation becomes persistent, the Central Bank of Nigeria may tighten monetary conditions through increases in policy rates and other measures. While monetary tightening may help moderate inflation, higher interest rates can make credit more expensive for businesses. This creates a policy dilemma: measures required to reduce inflation in the short run may simultaneously constrain investment and output growth.

A fifth problem is the interaction between inflation and exchange-rate instability. Nigeria’s dependence on imported goods and inputs means that exchange-rate movements can transmit inflation into domestic prices. At the same time, high domestic inflation can contribute to pressure on the exchange rate by reducing the competitiveness of domestic goods and increasing demand for foreign currency. This creates a potentially reinforcing relationship between inflation and macroeconomic instability.

A sixth problem is the effect of inflation on government expenditure and fiscal management. Rising prices increase the cost of public projects, government procurement, wages and social programmes. If government revenue does not increase sufficiently in real terms, inflation can intensify fiscal pressures. Higher interest rates associated with inflation control may also increase the cost of government borrowing.

Another important problem is that inflation may affect different sectors of the Nigerian economy differently. The effects on agriculture, manufacturing, services, construction and trade may vary depending on their dependence on imported inputs, energy, credit and consumer demand. Therefore, aggregate GDP growth may conceal important sector-specific effects.

The relationship between inflation and economic growth in Nigeria is also empirically unsettled. Omoke (2009) found no cointegrating relationship between inflation and economic growth for 1970–2005, while Chude and Chude (2015) reported a significant relationship for 2000–2009. More recent studies have reported negative effects of inflation on growth and evidence of threshold behaviour. These differences suggest that the inflation-growth relationship may be sensitive to the period examined, the methodology used and the economic conditions prevailing during the study period.

A further problem is that some earlier Nigerian studies do not cover the full period from 2000 to 2025. This is significant because the Nigerian economy experienced major structural and macroeconomic changes after 2020 and especially from 2023 onward. The reforms associated with fuel-subsidy removal and foreign-exchange-market changes generated substantial price pressures, making the later part of the period fundamentally different from earlier years.

The 2024 inflation episode was particularly important. The World Bank reports that inflation reached 33.2 percent in 2024, while the economy continued to expand at a moderate rate. By 2025, inflation had declined substantially, while growth remained around 4 percent. The coexistence of high inflation and positive GDP growth demonstrates why the relationship cannot be inferred simply from observing whether GDP is increasing or decreasing.

The CBN’s data also demonstrate the changing macroeconomic environment. According to the Bank, GDP growth moderated to 3.98 percent in the third quarter of 2025, while domestic inflation had declined substantially by December 2025. This recent experience raises questions about whether inflation reduction is associated with improved economic performance and whether the effects of inflation occur immediately or with a lag.

Another problem is the possibility of a threshold relationship. Evidence from Doguwa and Bangura and Omojolaibi suggests that inflation may not affect growth uniformly at all levels. If this is the case, maintaining inflation below a critical level may be more important for sustainable growth than merely reducing inflation from extremely high levels.

There is consequently a need for a comprehensive examination covering the 2000–2025 period. Such a study can incorporate the major economic events that occurred during the period and provide more recent evidence than studies that end before the post-pandemic and post-2023 reform period.

The central problem addressed by this study is therefore the persistent inflationary pressure experienced by Nigeria and the uncertainty surrounding its precise effect on economic growth over the 2000–2025 period. Although inflation and GDP have moved in different directions during different periods, the magnitude and significance of their relationship require empirical investigation.

This study consequently seeks to determine whether inflation has a significant impact on economic growth in Nigeria between 2000 and 2025. The findings are expected to provide evidence useful for understanding the inflation-growth nexus and for designing appropriate monetary and fiscal policies aimed at achieving price stability alongside sustainable economic growth.

1.3 Objectives of the Study

The main objective of this study is to examine the impact of inflation on economic growth in Nigeria from 2000 to 2025.

The specific objectives are to:

1. examine the trend of inflation in Nigeria from 2000 to 2025;
2. examine the trend of economic growth in Nigeria from 2000 to 2025;
3. determine the effect of inflation on economic growth in Nigeria during the period under study;
4. examine whether the relationship between inflation and economic growth in Nigeria is statistically significant; and
5. provide policy recommendations for maintaining price stability and promoting sustainable economic growth in Nigeria.

1.4 Research Questions

The study will provide answers to the following research questions:

1. What has been the trend of inflation in Nigeria from 2000 to 2025?
2. What has been the trend of economic growth in Nigeria from 2000 to 2025?
3. What effect has inflation had on economic growth in Nigeria during the period under study?
4. Is there a statistically significant relationship between inflation and economic growth in Nigeria?
5. What policy measures can help Nigeria achieve price stability while promoting sustainable economic growth?

1.5 Research Hypothesis

The following null hypothesis will be tested at the 5 percent level of significance:

H₀: Inflation has no significant impact on economic growth in Nigeria from 2000 to 2025.

1.6 Significance of the Study

This study will be significant to policymakers, monetary authorities, government agencies, businesses, investors, researchers and students.

Central Bank of Nigeria:
The findings will provide empirical evidence concerning the relationship between inflation and economic growth. This may assist the Central Bank of Nigeria in evaluating the growth implications of monetary-policy decisions designed to control inflation.

Federal Government of Nigeria:
The study may assist fiscal authorities in understanding the implications of inflation for economic growth and in developing policies that coordinate fiscal and monetary measures.

Policy Makers:
The findings may provide evidence useful in determining appropriate inflation-control strategies. Understanding whether inflation has a linear or potentially nonlinear relationship with growth can help policymakers formulate more effective stabilisation policies.

Businesses and Investors:
Businesses require predictable macroeconomic conditions for investment and production decisions. The findings may help businesses and investors better understand the implications of inflation for investment, production and economic activity.

Households:
Although the study is primarily macroeconomic, its findings may help explain how persistent inflation affects purchasing power and broader economic conditions.

Researchers:
The study will contribute to the existing literature on inflation and economic growth in Nigeria, particularly by covering the period through 2025.

Students:
The research may serve as useful academic material for students of economics, finance, accounting, business administration and related disciplines.

Government Economic Agencies:
Institutions responsible for economic planning and statistical management may find the study useful in understanding the historical interaction between inflation and economic growth.

1.7 Scope of the Study

The study focuses on the impact of inflation on economic growth in Nigeria from 2000 to 2025.

The independent variable is inflation, measured using the annual inflation rate based on the Consumer Price Index. The dependent variable is economic growth, measured using the annual growth rate of real Gross Domestic Product (GDP).

The study covers a 26-year period, from 2000 to 2025. The period was selected because it encompasses important phases of Nigeria’s economic development, including periods of relatively strong growth, the 2008 global financial crisis, the 2016 recession, the COVID-19 pandemic, the post-pandemic inflationary period and the macroeconomic reforms implemented from 2023.

The study is national in scope and does not focus on a particular state or sector. It examines Nigeria’s aggregate macroeconomic performance using annual secondary data obtained primarily from credible sources such as the World Bank, National Bureau of Statistics, Central Bank of Nigeria and, where appropriate, the International Monetary Fund.

1.8 Operational Definition of Terms

Inflation: A sustained increase in the general price level of goods and services in an economy over a period of time, resulting in a decline in the purchasing power of money.

Inflation Rate: The percentage change in the general price level, commonly measured through the Consumer Price Index (CPI), over a specified period.

Economic Growth: An increase in the real output of goods and services produced by an economy over time, usually measured by the percentage change in real GDP.

Gross Domestic Product (GDP): The monetary value of final goods and services produced within a country’s geographical boundaries during a specified period.

Real GDP: GDP adjusted for changes in the general price level, thereby providing a measure of actual changes in economic output.

Consumer Price Index (CPI): A statistical measure that tracks changes over time in the prices paid by consumers for a representative basket of goods and services.

Purchasing Power: The quantity of goods and services that can be purchased with a given amount of money.

Macroeconomic Stability: A condition in which key economic variables, including inflation, exchange rates, interest rates and output, remain sufficiently stable to support sustainable economic activity.

Inflation Threshold: A level of inflation beyond which the effect of inflation on economic growth changes, particularly from a potentially neutral or positive relationship to a negative relationship.

Economic Development: A broader process involving improvements in income, living standards, productivity, employment, structural transformation and social welfare.

1.9 Organisation of the Study

The study is organised into five chapters.

Chapter One presents the introduction, background of the study, statement of the problem, objectives of the study, research questions, research hypothesis, significance of the study, scope of the study, operational definitions and organisation of the study.

Chapter Two will review relevant literature on inflation and economic growth. It will cover the conceptual review, theoretical review and empirical review. The chapter will also discuss relevant theories, including the Keynesian perspective, quantity theory of money, Phillips Curve and relevant approaches to the inflation-growth relationship. The empirical literature will focus particularly on studies involving Nigeria and other developing economies.

Chapter Three will present the research methodology. It will discuss the research design, nature and sources of data, model specification, measurement of variables, estimation techniques, diagnostic tests and methods of testing the hypothesis.

Chapter Four will present the empirical results and analysis. It will include descriptive analysis, trend analysis, unit-root testing, estimation of the specified model, diagnostic tests and hypothesis testing. The findings will also be discussed in relation to the research questions and existing literature.

Chapter Five will present the summary of findings, conclusion and recommendations. It will also discuss the contribution of the study to knowledge and suggest areas for further research.

Project – The Impact of Inflation on Economic Growth in Nigeria: A Case Study of Nigeria, 2000–2025.