Public expenditure and economic growth nexus in nigeria a time series analysis

Public Policy and Administration Research www.iiste.org
ISSN 2224-5731(Paper) ISSN 2225-0972(Online)
Vol.4, No.7, 2014
97
Public Expenditure and Economic Growth Nexus in Nigeria: A
Time Series Analysis
MAKU, Olukayode Emmanuel
Department of Economics, Olabisi Onabanjo University,Ago-Iwoye, Ogun state, Nigeria.
E-Mail: kaymarks73@yahoo.co.uk
Abstract
This study examines the link between government spending and economic growth in Nigeria over the last three
decades (1977-2006) using time series data to analyze the Ram (1986) model. Three variants of Ram (1986)
model were developed-regressing Real GDP on Private investment, Human capital investment, Government
investment and Consumption spending at absolute levels, regressing it as a share of real output and regressing
the growth rate real output to the explanatory variable as share of real GDP, in other to capture the precise link
between public investment spending and economic growth in Nigeria based on different levels. Empirical
result showed that private and public investments have insignificant effect on economic growth during the period
under review. The paper test for presence of stationary using Augmented Dickey Fuller (ADF) unit root test
result reveals that all variables incorporated in the model were non-stationary at their levels. In an attempt to
establish long-run relationship between public expenditure and economic growth, the result reveals that the
variables are cointegrated at 5% and 10% critical level. With the use of error correction model to detect short run
behaviour of the variables, the result shows that for any distortion in the short-run, the error term restore the
relationship back to its original equilibrium by a unit. The paper main policy recommendation was that
government spending should be channel in order to influence economic growth significantly and positively in
Nigeria especially on education and infrastructural facilities.
Keywords:Government spending, public infrastructure, economic growth, human capital investment,
Government investment.
Jel Classification: E2, H50, H 51, H 52, H54
Section I Background to the study
The recent revival of interest in growth theory has also revived interest among researchers in verifying and
understanding the linkages between government spending and economic growth especially in developing
country like Nigeria.
Over the past decades, the public sector spending has been increasing in geometric term through government
various activities and interactions with its Ministries, Departments and Agencies (MDA’s), (Niloy et al. 2003).
Although, the general view is that public expenditure either recurrent or capital expenditure, notably on social
and economic infrastructure can be growth-enhancing although the financing of such expenditure to provide
essential infrastructural facilities-including transport, electricity, telecommunications, water and sanitation, waste
disposal, education and health-can be growth-retarding (for example, the negative effect associated with taxation
and excessive debt)
The size and structure of public expenditure will determine the pattern and form of growth in output of the
economy. The structure of Nigerian public expenditure can broadly be categorized into capital and recurrent
expenditure. The recurrent expenditure are government expenses on administration such as wages, salaries,
interest on loans, maintenance etc., whereas expenses on capital projects like roads, airports, education,
telecommunication, electricity generation etc., are referred to as capital expenditure. One of the main purpose of
government spending is to provide infrastructural facilities and the maintenance of these facilities requires a
substantial amount of spending. The relationship between government spending on public infrastructure and
economic growth tends to be an important analysis in developing countries, most of which have experienced
increasing levels of public expenditure overtime (World Development Report, 1994). Expenditure on
infrastructure investment and productive activities (in State-Owned Enterprises) ought to contribute positively to
growth, whereas government consumption spending is anticipated to be growth-retarding (Josaphat and Oliver,
2000).
However, economies in transition do spend heavily on physical infrastructure to improve economic welfare of
the people and facilitate production of goods and services across all sectors of the economy so as to stimulate
rapid growth in aggregate output. Empirical studies (like Ram, 1986; Deverajan et al., 1993; Nitoy et al., 2003)
have found that there exists positive correlation between economic growth and public spending on infrastructural
facilities. Manufacturing industries do consider infrastructure services or facilities before locating their
production base in order to gain large economies of scale and reduce cost of production. Also, to increase total
industrial output at a cheaper price in the economy.
Following the World Bank’s Development Report (1994), developing countries invest $200billion a year in new

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infrastructure representing 4 percent of their national output and a fifth of their total investment. The result has
been a dramatic increase in infrastructure services-for transport, power, water, sanitation, telecommunications,
and irrigation. The provision of infrastructure services to meet the demands of business, households, and other
users is on of the major challenges of economic development in developing countries like Nigeria.
The objective of the study is to investigate the link between government spending on and economic growth in
Nigeria. The remaining part of this study is divided into four sections. Section II deals with literature, theoretical
and empirical review. Section III highlights the methodological issues, section IV presents and analyses the
result while section V concludes and proffer policy recommendations.
Section II Literature, Theoretical and Empirical Review
2.0 Literature Review
2.1 Government Spending and Economic Growth
In a developed country, through economic stabilization, stimulation of investment activity and so on, public
expenditure maintains a rate of growth which is a smooth one. In an underdeveloped country, public expenditure
has an active role to play in reducing regional disparities, developing social overheads, creation of infrastructure
of economic growth in the form of transport and communication facilities, education and training ,growth of
capital goods industries, basic and key industries, research and development and so on (Bhatia, 2002). Public
expenditure on infrastructural facilities has a great role to play in the form of stimulating the economy.
The mechanism in which government spending on public infrastructure is expected to affect the pace of
economic growth depend largely upon the precise form and size of total public expenditure allocated to
economic and social development projects in the economy. When public expenditure is incurred, by itself it may
be directed to particular investments or may be able to bring about re-allocation of the investible resources in the
private sector of the economy. This effect, therefore, is basically in the nature of re-allocation of resources from
less to more desirable lines of investment. An important way in which public expenditure can accelerate the pace
of economic growth is by narrowing down the difference between social and private marginal productivity of
certain investments. Here, public expenditure on social and economic infrastructural like education, health,
transport, communication, water disposal, electricity, water and sanitation etc., has the potential of contributing
to the performance of the economy based on Promotion of infant industries in the economy; Reduction in the
unemployment rate; Stabilization of the general prices in the economy; Reduction in the poverty rate and
increase the standard of living of the people; Promotes economic growth by attracting foreign investment; and
Promotes higher productivity.
In tracing the work of Rosto and Musgrave, where they put forward development model under the causes for
growth in public expenditure. Under this model, public expenditure is a prerequisite of economic development.
The public sector initially provides economic infrastructure such as roads, railways, water supply and sanitation.
As economic growth take place, the balance of public investment shift towards human capital development
through increase spending on education, health and welfare services. In this model, the state is assumed to grow
like an organism making decision on unbehalf of the citizens. Society demand for infrastructural facilities such
as education, health, electricity, transport etc., grow faster than per capita income. In other word, as the economy
grows the demand for infrastructural facilities also increase for commensurate development in the economy this
is as result of the following:
Many societies are experiencing a growing population which becomes a major contributory factor in the
growth of public expenditure. The sheer scale of state services has to increase to keep pace with population
growth, including, for example, more schools, hospitals, and police etc.
Most countries have registered increasing urbanization. Existing cities grow and new ones come up.
Urbanization implies a much larger per capita expenditure on civic amenities. It necessitates a much larger
supply of incidental services like those connected with traffic, roads, schools etc.
Implementation of special economic plan necessitates increase in government spending like the
implementation of Structural Adjustment Programme (SAP) in 1986 which caused a sharp increase in public
expenditure in Nigeria.
2.2 Theoretical Review
Public expenditure theory, traditionally, received only a scanty attention till recently. Partly, this lop-sided
interest in the theory of public finance is explained by a general acceptance of the philosophy of laissez-faire and
belief in the efficacy of free market mechanism. However, with the advent of welfare economics the role of the
state has expanded especially in the area of infrastructural provision and theory of public expenditure is
attracting increasing attention. This tendency has been reinforced by the widening interest of economists in the
problems of economic growth, planning, regional disparities, distributive justice and the like (Bhatia, 2002).
The theory of public expenditure may be discussed in the context of increasing public expenditure, the range of
public expenditure and/or in terms of the division of a given amount of public expenditure into different items
like recurrent and capital expenditure. The later of the two parts may also be conceived in terms of allocation of

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the economy’s resources between providing public goods on the one hand and private goods on the other.
2.2.1 Theory of Increasing Public Expenditure. There are two
important and well-known theories of increasing public expenditure. The first one is connected with Wagner and
the other with Wiseman and Peacock.
WAGNER’S LAW OF INCREASING STATE ACTIVITIES
Adolph Wagner (1835-1917) was a German economist who based his Law of Increasing State Activities on
historical facts, primarily of Germany. According to Wagner, there are inherent tendencies for the activities of
different layers of a government (such as central, state and local governments) to increase both intensively and
extensively. There is a functional relationship between the growth of an economy and government activities with
the result that the governmental sector grows faster than the economy. From the original version of this theory it
is not clear whether Wagner was referring to an increase in
(a) Absolute level of public expenditure;
(b) The ratio of government expenditure to GNP; or
(c) Proportion of public sector in the economy.
Musgrave believes that Wagner was thinking of proportion of public sector in the economy. Nitti (1903)
not only supported Wagner’s thesis but also concluded with empirical evidence that it was equally applicable to
several other governments which differed widely from each-others (Nitti, 1903). All kinds of governments,
irrespective of their levels (say, the central or state government), intentions (peaceful or warlike), and size, etc.,
had exhibited the same tendency of increasing public expenditure.
WISEMAN-PEACOCK HYPOTHESIS
The second thesis dealing with the growth of public expenditure was put forth by Wiseman and Peacock in their
study of public expenditure in UK for the period 1890-1955. The main resent thesis of the thesis is that public
expenditure does not increase in a smooth and continuous manner, but in jerks or step like fashion. At times,
some social or other disturbance takes place creating a need for increased public expenditure which the existing
public revenue cannot meet. While earlier, due to an insufficient pressure for public expenditure, the revenue
constraint was dominating and restraining an expansion in public expenditure, now under changed requirements
such a restraint gives way.
The public expenditure increases and makes the inadequacy of the present revenue quite clear to every one. The
movement from the older level of expenditure and taxation to a new and higher level is the displacement effect.
The inadequacy of the revenue as compared with the required public expenditure creates an inspection effect.
The government and the people review the revenue position and the need to find a solution of the important
problems that have come up and agree to the required adjustments to finance the increased expenditure. They
attain a new level of tax tolerance. They are now ready to tolerate a greater burden of taxation and as a result the
general level of expenditure and revenue goes up. In this way, the public expenditure and revenue get stabilized
at a new level till another disturbance occurs to cause a displacement effect. Thus each major disturbance leads
to the government assuming a larger proportion of the total national activity. In other words, there is a
concentration effect. The concentration effect also refers to the apparent tendency for central government
economic activity to grow faster than that of the state and local level governments.
2.3 Empirical Review
Numerous studies have been conducted to investigate the relationship between government spending and
economic growth.
Landau (1983) found that the share of government consumption to GDP reduced economic growth which was
consistent with the pro-market view that the growth in government constrains overall economic growth. The
conclusions were germane to growth in per capita output and do not necessarily speak to increase in economic
welfare. Economic growth was also found to be positively related to total investment in education. In a later
study, Landua (1986), extends the analysis to include human and physical capital, political, international
conditions as well as a three year lag on government spending in GDP. Government spending was disaggregated
to include investment, transfers, education, defense and other government consumption. The results in part
mirrored the earlier studies in that general government consumption was significant and had a negative influence
on growth. Education spending was positive but not significant. It was unclear why lagged variables were
included given that the channels through which government influence growth suggest a contemporaneous
relationship.
Ram (1986) study marked a rigorous attempt to incorporate a theoretical basis for tracing the impacts of
government expenditure to growth through the use of production functions specified for both public and private
sectors. The data spanned 115 countries to derive broad generalizations for the market economics investigated.
He found government expenditure to have significant positive externality effects on growth particular in the
developing countries (LDC) sample, but total government spending had a negative effect on growth. Lin (1994)
used a sample of 62 countries (1960-85) and found that non-productive spending had no effect in growth in the
advanced countries but a positive impact in LDCs.

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100
Other studies have investigated the impact of particular (functional) categories of public expenditure. For
example, Deverajan et al (1993), using a sample of 14 OECD countries, found that spending on health, transport
and communication have positive impacts whereas spending on education and defence did not have a positive
impact. In the majority of studies, total government spending appears to have negative effect on growth (Romer,
1990; Alexander; 1990; Folster and Henrekson; 1999).
Seymour et al. (1997), used a disaggregated approach to examine the impact of government expenditure on
economic growth in the OECD. Their study is similar to Cashin (1995) but it opens new grounds by focusing on
the short to medium term impact of fiscal policy and incorporates the distortionary effects of government
activities using four regression models and a fixed effect model with a least square dummy variable (LSDV)
model. They found that all the regressors had the correct signs including capital which along with housing, roads,
education were insignificant. The non-linear term for education was highly significant and positive corroborate
the endogenous growth literature contention that human capital yields increasing returns to scale and
nonlinearity in production. The nonlinear term of health was found significant also but was negative implying
that health expenditure can be distortionary. Josaphat et al. (2000), investigated the impact of government
spending on economic growth in Tanzania (1965-1996) using time series data for 32years. They formulated a
simple growth accounting model, adapting Ram (1986) model in which total government expenditure is
disaggregated into expenditure on (physical) investment, consumption spending and human capital investment. It
was found that increased productive expenditure (physical investment) have a negative impact on growth and
consumption expenditure relates positively to growth, and which in particular appears to be associated with
increased private consumption. The results revealed that expenditure on human capital investment was
insignificant in their regression and confirm the view that public investment in Tanzania has not been productive,
as at when the research was conducted.
Nitoy et al. (2003) employed the same disaggregated approach as followed by Josaphat et al. (2000). They
examined the growth effects of government expenditure for a panel of thirty developing countries (including
Nigeria) over the decades of the 1970s and 1980s, with a particular focus on sectoral expenditures. The primary
research results showed that the share of government capital expenditure in GDP is positively and significantly
correlated with economic growth, but current expenditure is insignificant. The result at sectoral level revealed
that government investment and total expenditures on education are the only outlays that remain significantly
associated with growth throughout the analysis. Although public investments and expenditures in other sectors
(transport and communication, defense) was found initially to have significant associations with growth, but do
not survive when government budget constraint and other sectoral expenditures were incorporated into the
analysis. Also private investment share of GDP was found to be associated with economic growth in a
significant and positive manner.
Junko and Vitali (IMF, 2008) investigate the impact of government expenditure on economic growth in
Azerbaijan because of the temporarily oil production boom (2005-07), which caused expectationally large
expenditure increase aimed at improving infrastructure and raising incomes. Azerbaijan’s total expenditure
increased by a cumulative 160 percent in nominal value from 2005 to 2007 (i.e. from 41 percent of non-oil GDP
to 74 percent). In their research reference were made to Nigeria and Saudi Arabia (1970-89) who have also
experienced oil boom and increased government expenditure over the years. The study simulated the neo-
classical growth model tailored to the Azeri conditions. Their analysis suggested that the evaluated fiscal
scenario poses significant risks to growth sustainability and historical experience indicates that the initial growth
performance largely depends on the efficiency of scale-up expenditure. The study also sheds light on the risks
associated with a sudden scaling-down of expenditure, including the political difficulties to undertake an orderly
expenditure reduction strategy without undermining economic growth and the crowding-out effects of large
government domestic borrowing.
Section III Methodological Issues
3.1 Theoretical Model.
In order to capture the precise relationship between government spending and economic growth, we specified an
empirical model that incorporates the effect of government consumption and investment spending, and private
investment on real gross domestic product in Nigeria is specified.
We follow the model of Ram (1986) used for a panel of 115 countries both developed and developing, which
forms a basis of our empirical model of government expenditure and growth. Denoting the private sector D and
public sector G, with capital (K) and labour (L) allocated between both such that K = KD + KG, and L = LD + LG.
To capture externalities associated with the public sector, G enter the production function of the private sector D:
D = D(KD, LD, G) (3.1)
G = G(KG, LG) (3.2)
We assume a constant productivity differential between labour in both sectors:

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101
∂+= 1
L
L
D
G (3.3)
Where 0>∂ implies lower productivity in the public sector (the reverse would be the case if 0<∂ and we
assume 0≠∂
Totally differentiating (1) and (2) given that national income Y = D + G, gives
dY = DKdKD + GKdKG + DLdLD + DGdG (3.4)
Where Dk and Gk are marginal products of factor K in sector D and G respectively, similarly, DL and GL.
Further, DG is the marginal externality effect of public on private sector. From (3) we can write:
GL = ( ∂+1 )DL (3.5)
Josaphat et al. (2000) diverge slightly from Ram (1986) because, they avail of the identity L = LD + LG, we will
treat capital as distinct in each sector. Substituting (5) into (4) and rearranging:
dY = DKdKD + GKdKG + DL (dLD + dLG)+ DLdLG + DGdG (3.6)
Using (5) we can write:
dG = GKdKG + ( ∂+1 ) DLdLG
which implies:
GLG
K
dLDdK
GdG
=
∂+
−
∂+ 11
(3.7)
Substituting (7) into (6) and collecting terms:
dGDdLDdKGdKDdY GLGKDK 





∂+
∂
+++





∂+
∂
−+=
11
1 (3.8)
We assume the existence of a linear relationship between the marginal product of labour in each sector and the
average output per unit labour in the economy, i.e. DL = ( )L
Y
Letting dKD = Ip (private sector investment), and dKG = IG (public sector physical investment), we can substitute
into (8), dividing through by Y:
( )( )Y
G
G
dGD
L
dL
Y
I
Y
I
Y
dY
G
GP






∂+
∂
++++=
1
(3.9)
Where KK GandD =





∂+
∂
−=∂
1
1,
Equation (9) corresponds to Ram (1986) equation (7) except we keep IP and IG distinct. Thus, equation (9) forms
our basic model for regression estimation. For ease of comparison with other studied, we will estimate (9) with
(G/Y) as the variable rather than (dG/G) (G/Y). Since, we do not have time series data on
(dL/L) and time series on public investment in human capital (Hg) is used as a proxy. We wish to investigate if
Hg has an independent impact on growth, as growth theory predicts (Romer, 1990; Barro, 1990; Easterly and
Rebelo, 1993). The Hg incorporates government spending on social infrastructures like health and education.
We will estimate (9) as:
U
Y
C
b
Y
H
b
Y
I
b
Y
I
bbg
gggp
+





+





+





+





+= 43210
(3.10)
Where: Cg = Government consumption spending
Ig = Government investment spending
Hg = Government human capital investment spending
Ip = Private investment
g = dY/Y or Y, measured as (In Yt – In Yt-1)
u = error term
We use time series data on Nigeria for a 30 year period (1977 – 2006). This time frame was chosen
based on the availability of reliable data on public spending components as at the commencement of this study.
Private investment (Ip) is proxied by private capital formation, while government investment spending (Ig) is
proxied by government total capital/development expenditure. Government consumption expenditure (Cg) is
measured by government recurrent expenditure less expenditure on health and education. Expenditure on human
capital (Hg) is thus measured by the total of health and education spending (current and capital). All variables are
measured in real terms.
3.2 Apriori Expectation
Public expenditure on infrastructure investment and productive activities-like electricity, telecommunication,
health, education, transport, water, sanitation and irrigation are expected to contribute positively to economic
growth, whereas government consumption spending is anticipated to be growth retarding. Therefore, public
expenditure on social and economic infrastructure is theoretically expected to have positive impact on economic

Vol.4, No.7, 2014
102
growth. Also, private investment is expected to have positive impact on economic growth. This can be
represented mathematically as follows:
0,0,0,0 <>>>
GGGP dC
dY
and
dH
dY
dI
dY
dI
dY (3.11)
3.3 Sources of Data and Estimation Procedure
Data are purely secondary in nature. The data used are presented in the appendix and sourced from Statistics
Bulletin of the Central Bank of Nigeria (CBN) and Annual Abstract of Statistic of the National Bureau of
Statistic (NBS). The Classical Least Square (CLS) method is used to analyse the data and investigate the
relationship between government spending on public infrastructure and economic growth in Nigeria. Regression
model is adopted to know the precise effect of government expenditure on economic growth in Nigeria and for
estimation simplicity. Also, co-efficient of determination (R²), T-statistic, F-statistic, and Durbin Watson test are
used to evaluate the significance of the estimated parameters of the regression model. The study also attempt to
test for the time series characteristics using Augmented Dickey Fuller (ADF) Unit Root Test and Augmented
Engle-Granger Cointegration test.
Section IV PRESENTATION AND INTERPRETATION OF RESULT
4.1 REGRESSION: ABSOLUTE
Source: Extracted from E-Views 5.1 Output
The specified model is
UCbHbIbIbbY gggP +++++= 43210
Using the absolute values of all the variables, the estimated model is:
gggP CHIIY 306.0474.10.1340.924195248.5 +−++=
The estimated model shows that there exist positive relationship between Real GDP and the explanatory
variables – private investment, government investment spending and government consumption spending. This is
in conformity with the theoretical expectation excluding government consumption spending which is expected to
be growth retarding. Also, human capital investment is found to have negative relationship with real GDP
contrary to a priori.
The estimated regression reveal that a unit change in private investment (IP), government investment spending (Ig)
and government consumption spending (Cg) will enhance real GDP by values of 0.924, 0.134 and 0.306
respectively. Likewise, one present change in human capital investment will retard growth by 1.474.The t-
statistic is used to test for individual significance of the estimated parameters (b1, b2, b3 and b4). The result
reveals that all the parameters are not significant, because their t-calculated is less than t-tabulated (2.04). Then,
the null hypothesis is accepted.
The F-statistic is used to test for simultaneous significance of all the estimated parameters and the result showed
that they are all simultaneously significant. It’s because the F-calculated (13.025) is greater than F-tabulated
(2.74). The Durbin–Watson test shows that there is presence of positive serial correlation in the residuals,
because the d-value (0.523) is greater than zero but less than two.
The econometric analysis of the link between public expenditure and economic growth in Nigeria during the
review period have shown that private investment, government investment spending, and government

Vol.4, No.7, 2014
103
consumption spending have positive impact on economic growth but the effect is insignificant. Also, the
negative effect of human capital investment on real GDP is not significant. Therefore, their parameters are
statistically assumed to be zero. In conclusion, the null hypothesis is accepted which implies that government
spending has no significant impact on economic growth in Nigeria during the review period.
4.2 REGRESSION: LAGGED AT FIRST DIFFERENCE
The specified model is:
u
Y
C
b
Y
H
b
Y
I
b
Y
I
bbdY
gggp
+





+





+





+





+= 43210
Using the proportional values of the explanatory variables to Real GDP (Y), the estimated model is:






+





+





−





−=
Y
C
Y
H
Y
I
Y
I
dY
gggp
091.13471956.261781.288564360.20268.20511
The estimated regression model shows that private investment and government investment spending have a
negative relationship with real GDP, which is not in line with the a priori expectation. The human capital
investment and government consumption spending have positive impact on economic growth which conforms to
the theoretical basis excluding government consumption spending that is expected to be growth retarding.
The estimated regression model reveals that a percentage increase in private investment and government
investment as a share of real output will retard economic growth by values of 20.360 and 28,864.1 respectively.
Likewise, a percentage change in human capital investment and government consumption spending as a share of
real output will enhance economic growth by values of 26,178.956 and 13,471.091 respectively.
The result of the t-statistic reveals that the individual estimated parameters are not significant and they are
statistically assumed to be zero because their t-calculated is less than t-tabulated (2.04). Therefore, the null
hypothesis is accepted for each of the estimated parameter (b1, b2, b3 and b4) of the explanatory variables.
Also, the result of the F-statistic reveals that the estimated parameters are not simultaneously statistically
significant because the F-calculated (0.106) is less than F-tabulated (2.76).
The co-efficient of determination (R2
) shows that the data which are in share of real GDP (Y) does not fit the
model because 1.7% of the total variation in the first difference of real GDP is only explained by variation in
private investment, government investment spending, human capital investment and government consumption
spending (all as share of real GDP (Y) ).
The Durbin-Watson test shows that there is presence of negative serial correlation in the residuals, because the d-
value (2.517) is greater than two.
The analysis showed that the components of public expenditure and private investment have no significant
influence on real GDP, when measured as a share of real output. The negative contribution of private investment
and government investment as share of real output on real GDP (dY) is not in line with theoretical expectation.
Also, human capital investment as share of real GDP has the highest positive contribution to real output
compared to government consumption spending that does not conform to theoretical expectation. Although, both
have insignificant contribution on real output in Nigeria during the review period.
In conclusion, the null hypothesis is accepted, which implies there is no significant impact of public expenditure
on economic growth in Nigeria during the period.

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104
4.3 REGRESSION: GROWTH RATE
u
Y
C
b
Y
H
b
Y
I
b
Y
I
bbg
gggp
+





+





+





+





+= 43210
Regressing the growth rate first lagged real GDP to private investment (Ip/Y), government investment (Ig/Y),
Human capital investment (Hg/Y) and government consumption spending (Cg/Y), the estimated model is






−





+





−





−=
Y
C
Y
H
Y
I
Y
I
g
gggp
033.0275.0238.0036.0225.0
The estimated model shows that private investment, government investment spending and government
consumption spending have negative relationship with the growth rate of real GDP, in which there relationship is
not in conformity to theoretical expectation excluding government consumption spending (which conforms).
Also, there is positive relationship between human capital investment and growth rate of real GDP and this
conforms to theoretical expectation.
The estimated reveal that a unit changes unit change in private investment, government investment spending and
government consumption spending as share of real output will have a negative influence on the growth rate of
real GDP by values of 0.036, 0.238, and 0.033 respectively. Also, a percentage change in human capital
investment as share of real output will enhance the growth rate of real GDP in the economy by a value of 0.275.
The t-statistic results reveal that the individual estimated parameters (b1, b2, b3, and b4) are not statistically
significant because their t-calculated is less than t-tabulated (2.04). Therefore, the null hypothesis is accepted for
each of the explanatory variables. This implies that they have no significant effect on the growth rate of real
GDP.
The test for simultaneous significance of all the estimated parameters, as measured by F-statistic reveals that
they are not simultaneously statistically significant, because the F-calculated (0.184) is lesser than the F-
tabulated (2.76). Then, the null hypothesis is accepted for all the estimated parameters. This implies that public
expenditure has no significant impact on the growth rate of real output in Nigeria.
The co-efficient of determination (R2
) shows that the data which are measured as share of real GDP does not fit
the specified model because 2.9% of the total variation in the growth rate of real GDP is explained by variation
in private investment, government investment spending, human capital investment and government consumption
spending.
The Durbin-Watson test reveals that there is presence of negative serial correlation in the residuals of the model
because the d-value (2.088) is greater than two.
The econometric analysis of the link between government spending and economic growth in Nigeria from 1977
to 2006, using the growth rate analysis, reveal that private investment, government investment spending and
government consumption spending as share of real GDP have negative and insignificant effect on the growth
rate of real output in Nigeria during the review period. Likewise, human capital investment like health and
education has the highest contribution on the growth rate of real GDP. But, its contribution to real output is
insignificant.
From the analysis, the co-efficient of determination (R2
) shows that the incorporated variables in the model do

Vol.4, No.7, 2014
105
not really explain variation in the growth rate of real GDP in Nigeria. The regression model may be taken to be
spurious or non-sensical. Therefore, the specified model does not explain the link between public expenditure
and economic growth in Nigeria using the growth rate analysis, even since all the estimated parameters are
simultaneously insignificant.
4.4 UNIT ROOT TEST ANALYSIS
An attempt was made to investigate the time series characteristics of the variables (Ip, Ig, Hg, Cg and
rdgp) of the model in this study. A variable is stationary when it has no unit root which is denoted in literature as
I(0). A non-stationary variable can have one or more unit roots and denoted as I(d), d is the number of unit roots
that the variables possesses and, by implication, the number of unit roots that the variable must be differenced in
order to make it stationary. Similarly, if a time series has to be differenced twice (i.e. take the first difference of
the first differences) to make it stationary, we call such a time integrated of order 2.
Table 1: ADF Unit Root Test Result
Tau-ADF in level Tau-ADF in first difference
Variable None Intercept Trend & Intercept None Intercept Trend & Intercept Num of Lag Order of Integration
Ip 6.318438* 5.158303* 3.279577* 0.94995 0.449987 -0.525467 0 I(2)
Ig 0.412363 -0.383381 -2.565201 -7.564516 -8.029247 -8.434491 0 I(1)
Hg 3.569800 2.709972 0.771951 -3.777578 -4.414288 -6.026676 0 I(1)
Cg 3.972792* 2.705643 0.070912 -3.397149 -4.11163 -5.979626 0 I(1)
RGDP 1.222242 -0.42745 -2.881367 -6.152189 -6.811586 -6.751653 0 I(1)
1% CV -2.6453 -3.6752 -4.3082 -2.6486 -3.6852 -4.3226
5% CV -1.953 -2.5731 -3.5731 -1.9535 -2.9705 -3.5796
10% CV -1.6218 -2.622 -3.2203 -1.6221 -2.6242 -3.2239
Tau-ADF in second difference
Variable None Intercept Trend & Intercept Num of Lag Order of Integration
Ip -6.05287 -6.329094 -7.109719 0 I(2)
1% Critical value -2.6522 -3.6959 -4.3382
5% Critical value -1.954 -2.975 -3.5867
10%Criticalvalue -1.6223 -2.6265 -3.2279
Note: * means the time series is explosive
As depicted in Table 1, all the variables are stationary at the first difference for each of the forms of
estimation (i.e. none, intercept, and both trend and intercept), excluding private investment which is stationary at
second difference for all the three forms of a random walk model. This implies government investment spending
(Ig), human capital investment (Hg), government consumption spending (Cg) and real GDP (rgdp) are integrated
of order one i.e. I(1). But, the time series for private investment (Ip) is integrated of order two i.e. I(2).
4.5 COINTERATION TEST: LONG-RUN ANALYSIS
UNIT ROOT TEST FOR RESIDUAL FROM THE ESTIMATED REGRESSION AT LEVEL We
have assumed that all the variables are of the same order of integration i.e. I(2), in order to carry out further tests.
We then run an OLS regression of the variables on levels and test for cointegration by testing that the residual is
I(1). This is the long run dynamic.
The unit root test for the residual is carried out as follows:
uCbHbIbIbbY gggp +++++= 43210
The residual series is generated from the estimated model as shown below:
gggp CHIIY 306.0474.1134.0924.05.195248 +−++=
)306.0474.1134.0924.05.195248( gggpt CHIIYU +−++−=
The ADF is used to test whether the residual is stationary or non-stationary. Since the estimated Ut are
based on the estimated cointegrating parameters b1, b2, b3 and b4, the ADF critical significance values are not
quite appropriate. Engle and Granger have calculated these values. Therefore, the ADF test in the present
context is known as Augmented Engle-Granger (AEG) test. The result from the analysis revealed that the
residual (U) is stationary at 5% and 10% critical level since the tau value -2.170693 is more negative than the
critical values, the null hypothesis of no cointegration is rejected. In conclusion, the residuals from the regression
of RGDP on Ip, Ig, Hg, and Cg as specified below

Vol.4, No.7, 2014
106
uCbHbIbIbbY gggp +++++= 43210
are integrated of order zero i.e. I(0); that is , they are stationary. Hence,
gggp CHIIY 306.0474.1134.0924.05.195248 +−++=
is a cointegrating regression and this regression is not spurious, even though individually the incorporated
variables in the model are non-stationary at levels but all are stationary at first difference excluding private
investment that is stationary at second difference. Therefore,
gggp CHIIY 306.0474.1134.0924.05.195248 +−++=
shows the static or long-run function of the relationship between public expenditure and economic growth in
Nigeria.
4.6 ERROR CORRECTION MECHANISM (ECM): SHORT-RUN ANALYSIS
We just showed that RGDP, Ip, Ig, Hg, and Cg are cointegrated at 5% and 10% critical levels; that is,
there is long-run relationship among them. In the short run there may be disequilibrium in which the
)306.0474.1134.0924.05.95248( gggpt CHIIYU +−++−= is the
“equilibrium error.” Therefore, the error term is used to show the short run behaviour of Real GDP to its long-
run values.
We specify ECM equation for this study as follows:
tttgtgtgtpt uCHIIY εαααααα ++∆+∆+∆+∆+=∆ −15)(4)(3)(2)(10
where ∆ denotes the first difference operator, tε is a random error term, and
)(=u )1()1()1()1( 432101-t −−−−
−−−−− tttt gggp CbHbIbIbbY , that is, the one-period lagged value of the error from the
cointegrating regression.
The ECM equation above states that ∆RGDP depends on change in the explanatory variables and also on
equilibrium error term that determines the short run behaviour of the model.
The ECM equation is estimated through the use of SPSS 15.0 and the result extracted from the SPSS Output is
given in table 2.
Table 2: Short-run Analysis Result
Short run Regression Analysis: ECM
The estimated regression equation is
1)()()()(
000.1306.0474.1134.0924.0004.0 −+∆+∆−∆+∆+=∆ ttgtgtgtpt uCHIIY
Source: Extracted from SPSS version 15.0 Output
Since 1−tu is positive (i.e., RGDP is above its equilibrium value), 15 −tuα will need to negative which
will cause ∆RGDPt to be negative. Therefore, leading RGDPt to fall in period t. Thus, the absolute value of 5α
(1.000) decides how quickly the equilibrium is restored i.e. 1−tu is the mechanism that adjusts to the long run
equilibrium by a unit of any distortion that may occur in the short run.
The estimated ECM equation above shows that the short run changes in Ip, Ig and Cg have positive and
significant impact on the short run changes in RGDP. Likewise, the short run changes in Hg have negative and
significant impact on the short run changes in RGDP. Therefore, the estimated parameters ,,, 321 ααα and 4α
Coefficientsa
.004 .096 .044 .965
.924 .000 .565 284202.8 .000
.134 .000 .209 130423.5 .000
-1.474 .000 -.633 -312119 .000
.306 .000 .383 243601.9 .000
1.000 .000 1.208 709111.6 .000
(Constant)
LAG.PRINVT
LAG.GOVINV
LAG.HUMINV
LAG.GOVCON
LAG.U
Model
1
B Std. Error
Unstandardized
Coefficients
Beta
Standardized
Coefficients
t Sig.
Dependent Variable: LAG.GDPa.

Vol.4, No.7, 2014
107
are the short run marginal effect on Real GDP (Y).
Section V Summary, Conclusion and Recommendation
5.1 Summary of Major Findings
The empirical analysis of the study follows the model of Ram (1986). Three variants of Ram (1986)
model were developed and estimated, using the statistical package for social science (SPSS) version 15.0.
The first model was estimated based on the absolute values of the variables incorporated in the model.
The result showed that private investment, government investment spending and consumption spending have
positive but insignificant effect on economic growth in Nigeria during the review period. Also, human capital
investment was found to have negative and insignificant effect on real output. Therefore, the null hypothesis is
accepted which implies that government spending has no significant effect on real gross domestic product.
The second variant of Ram (1986) model was developed because of the insignificant nature of the
estimated parameters of the first model and also because of the non-conformity of some parameters to theoretical
expectation. The estimated model revealed that private investment and government investment spending as share
of real output have negative and insignificant effect on lagged real GDP. Also, human capital investment and
government consumption spending were found to have positive but insignificant impact on first differenced of
real GDP at period t. Therefore, the null hypothesis was accepted, which implies there is no significant
contribution of government expenditure as share of real output on economic growth in Nigeria.
The third variant of Ram (1986) model was developed due to the unsatisfactory result of the first and
second models. The estimated model showed that only human capital investment as share of real output has
positive but insignificant effect on the growth rate of real GDP during the review period. While, others were
found to have negative and insignificant effect on the growth rate of real GDP. Therefore, the third model was
concluded to be spurious because the estimated parameters were simultaneously insignificant and the computed
data does not really fit the model as a result of the 2.9% of the total variation in the growth rate of real GDP that
is explained by the explanatory variables incorporated in the model.
We found that Real GDP, private investment, government investment spending, government
consumption spending and human capital investment are cointegrated i.e. there exist long run relationship
between government expenditure and economic growth in Nigeria. The Error Correction Mechanism (ECM) is
used to model the short run analysis and the result shows that for any distortion in the short run the error term
restore the relationship back to its equilibrium by a unit.
A plausible explanation for the results is that our time series is relatively short and the quality of the
data is less than ideal. This may be adduced to misappropriation of public funds at all levels that is meant for
execution of capital projects. Even though, most of the capital projects are over estimated based on cost of
execution and often abandoned before completion.
Our econometric evidence is also in line with the findings of Josaphat et al. (2000). They used time
series data on Tanzania for 31-year period (1965-1996). They found Real GDP, Private investment, Human
capital investment, Government investment and consumption spending to be non-stationary at levels and the null
hypothesis for no cointegration is rejected. Also, Private and Public investments were found to have insignificant
impact on growth.
From this research study, it can be concluded that government expenditure and private investment have
no significant influence on economic growth in Nigeria based on the research analysis. It also reveals that Real
GDP, private investment, human capital investment, government investment and consumption spending have not
maintained a uniform pattern since 1977 to 2006 as a result of persistent random shock effect on the time series.
Therefore, the Federal Government expenditure has not shown any considerable structural shift over the review
period. The results also showed that the rate of government expenditure to real GDP has been rising since the
Structural Adjustment Programme (SAP) without significant contribution towards economic growth in Nigeria.
5.2 Policy Recommendations
Emanating from the result, for private investment and various components of government expenditure like
human capital investment, government consumption and investment spending to have significant impact on
economic growth, the following policy options are recommended:
1. Government should monitor the contract awarding process of capital projects closely, to prevent against
over estimation of execution cost. This will bring about significant impact of public investment
spending on economic growth.
2. There should be effective channeling of public fund to productive activities, which will have a
significant impact on economic growth.
3. There should be joint partnership between the government and the private sector in providing essential
infrastructural services that will promote economic growth and development.
4. The government consumption spending should be well coordinated by all arms of government to
prevent “crowd out” effect on government investment.

Vol.4, No.7, 2014
108
5. There should be high degree of transparency and accountability on government spending at various
sectors of the economy in order to prevent channeling of public funds to private accounts of
government officials.
References
Bhatia H.L (2002): Public Finance, 25th Edition, Vikas Publishing House, PVT Ltd, India. Carlos H.O (2004):
An Economic Growth Model Showing Government Spending with reference to Colombia and Learning-by-
doing: Colombia Economic Journal, Vol. 2, No. 1, 2004.
Folster and Henrekson (1999): Growth Effects of Government Expenditure and Taxation in Rich
Countries;European Economic Review, 45, Pg. 1501-1520.
Josaphat, P. K and Oliver M (2000): Government Spending and Economic Growth in Tanzania, 1965-996:
CREDIT Research Paper.
Junko K. and Vitali K. (2008): Impact of Government Expenditure on Growth: The Case of Azerbaijan:
International Monetary Fund (IMF) working paper. WP/08/115.
Landau, D. (1983): Government Expenditure and Economic Growth: a Cross- Country Study. Southern
Economic Journal, Vol. 49, No, 3, Pg. 783-92.
Landau, D. (1986): Government and Economic Growth in the less Developed Countries: An Empirical study for
1960-1980. Economic Development and cultural changes, Vol. 35, Pg 35-37.
Lin, S. (1994); Government spending and economic growth: Applied Economics, Volume 26.
Niloy, B., Emranul. M.H and Denise. R.O (2003): Public Expenditure and Economic Growth: A Disaggregated
Analysis for Developing Countries, JEL, Publication.
Ram, R. (1986): Government Size and Economic Growth: A new Framework and some Empirical Evidence
from Cross-sectional and Time Series Data. American Economic Review, Vol. 76, Pg. 191-203.
Romer, P.M (1990): Human Capital and Growth: Theory and Evidence; Carnegie Rochester Conference Series
on Public Policy, Vol. 40.
Seymour. D and Oral, W: (1997): The impact of Government Expenditure on Economic Growth in the OECS; A
Disaggregated approach, World Bank Research.
World Bank (1994): Infrastructure for Development World Development Report, Oxford University Press.

Vol.4, No.7, 2014
109
Appendix
YEAR RGDP PRI.INVT GOV.INVT HUM.INVT GOV.COM
1977 106,488.00 2531.4 5004.6 962.2 3471.1
1978 100,116.00 2863.2 5200 692.1 2458.9
1979 108,955.00 3153.1 4219.5 1085.8 2730.8
1980 117,334.00 3620.1 10163.4 1852.3 4052.7
1981 98,594.10 3757.9 6567 1233 4183.2
1982 93,594.00 5382.8 6417.2 1421.1 4083.2
1983 83,519.60 5949.5 4885.7 1247 4514.5
1984 66,462.20 6418.3 4100.1 1051.4 4972.1
1985 71,368.10 6804 5464.7 1074.1 6739
1986 257,784.40 9313.6 8526.8 1455.2 6764.9
1987 255,997.00 9993.6 6372.5 889.9 14964.9
1988 275,409.60 11339.2 8340.1 1527.3 18347.1
1989 295,090.80 10899.6 15034.1 2394.4 23947.7
1990 472,648.70 10436.1 24048.6 2952.4 33855.9
1991 328,644.50 12243.5 28340.9 2311.2 36359
1992 337,288.60 20512.7 39763.3 3085.8 51558.5
1993 342,540.50 66787 54501.8 10683.6 73375.9
1994 345,228.50 70714.6 70918.3 13311.6 75974
1995 352,646.20 119391.6 121138.3 17789.6 120142.7
1996 367,218.10 122600.9 158678.3 20203.3 108963.3
1997 377,830.80 128331.9 269651.7 21747 143248.3
1998 388,468.10 152410.9 309015.6 38705.6 159309
1999 393,107.20 154190.4 498037.6 47743.8 417822
2000 412,332.00 157508.6 239450.9 85749.9 405770.4
2001 431,783.10 161441.6 438696.5 104396.1 514921
2002 451,785.60 166631.6 321378.1 172626.4 716533.1
2003 495,007.10 178478.6 241688.6 119121.6 886257.7
2004 527,576.00 249220.6 351259.9 153555.3 927146
2005 561,931.40 324656.7 519510 191720.9 1081103
2006 595,821.61 481239.1 552385.8 270803.7 1093230
Source: CBN Statistical Bulletin of several issues.
NBS Annual Abstract of Statistic

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