Article Type : Research Article
Authors : Seraj M and Sheriff H
Keywords : Digital infrastructure; Human capital; Life expectancy; Economic growth; ARDL; Burkina Faso; Cointegration; Mobile cellular subscriptions; Internet usage
This
study aims to analyze the relationship between the development of digital
infrastructure and human capital and economic growth in Burkina Faso from 1996
to 2024. This research examines the long run and short run relationships of
real GDP per capita with mobile cellular subscriptions, internet use, life
expectancy at birth and gross fixed capital formation using a pure time-series
Autoregressive Distributed Lag (ARDL) bounds-testing approach. The unit root
test result is consistent with all variables being integrated of order one.
There is a stable long run cointegration relationship between the series at the
1 percent significance level as suggested by the bounds test. The estimated
life expectancy at birth, with individual statistical significance, is a
positive determinant of real GDP per capita; the estimated mobile cellular
subscriptions and the estimated internet usage and gross fixed capital
formation are not individually statistically significant. The error-correction
term is negative and significant which suggests that about 50.61 percent of any
error from the long-run equilibrium is corrected within one year. The serial
correlation and the heteroskedasticity tests from residual data are not
evident, and the CUSUM and the CUSUM of Squares are used to check for stability
of the parameters. The results point to the critical importance of
health-capital accumulation in the economy's growth over time in Burkina Faso
and indicate that growth impacts of digital infrastructure might vary depending
on the interaction of these omitted factors and the linear specification.
Economic
growth remains one of the most fundamental objectives of economic policy in
developing countries. A sustained improvement in real output per capita is
known to be the most important determinant of the improvement in living
standards, reduction of absolute poverty, increased employment opportunities
and the fiscal resources required for public investment in infrastructure,
education and health [1,2]. In Sub-Saharan Africa, and especially for Sahelian
countries, high poverty rates make it particularly difficult to ensure both
strong economic growth and sustainable growth. These economies are
characterized by multiple structural constraints such as limited physical
capital, low human capital, high reliance on rain-fed agriculture, exposure to
climatic shocks, low institutional capacity, and geographic disadvantages of
land-locked status in many cases [3,4]. Burkina Faso is a case in point in this
general landscape. It is a Sahelian land-locked and low-income nation, which
has been traditionally dependent on agriculture, gold mining and official
development assistance. Growth has been patchy, and often followed by droughts,
price volatility for commodities and periods of political unrest. In this
context, two potentially game-changers have taken place in the last 30 years.
The first is the quick growth of digital infrastructure, particularly mobile
cellular networks and, more recently, Internet access. The second is the
continuous health gains, most evident in the increase in life expectancy at
birth.
Also
important is the timeframe that was analyzed (1996-2024). It starts when mobile
cellular subscriptions in Burkina Faso were still small and Internet use was
nonexistent and continues to the years of rapid mobile penetration and the
gradual availability of Internet access as well as the continued improvements
in life expectancy. This long span is appropriate for exploring long-term
relationships, since it encompasses both the early and later stages of digital
diffusion and of accumulation of health-capital. In light of these
considerations, the present study investigates the impact of digital
infrastructure—measured by mobile cellular subscriptions and individuals using
the Internet—and human capital development—measured by life expectancy at
birth—on economic growth in Burkina Faso, while controlling for physical
capital formation. The analysis utilizes the ARDL bounds-testing methodology
suggested by Pesaran, Shin and Smith which is suitable for the small-sample and
country-specific time-series context and can simultaneously address long-run
equilibrium analysis and short-run adjustment dynamics [5].
Statement
of the problem
Burkina
Faso has made significant gains in some aspects of development over the last 30
years. The number of mobile cellular subscriptions had increased from close to
zero to more than 100 subscriptions per 100 people. Although the use of the
Internet remains fairly low in global terms, over the last few years it has
grown from a negligible level to over one-quarter of the population. The life
expectancy at birth has increased consistently, paralleled by improvements in
public health, nutrition and disease prevention. Gross fixed capital formation
has been within a fairly narrow range and has been an essential part of
aggregate demand and productive capacity. All the above have not succeeded in
improving real GDP per capita, which is low by international standards and has
increased rather modestly. The seeming mismatch between the growth of digital
and health capital and the relatively small increase in average living
standards is the major empirical puzzle that propelled the present study.
A
number of possible explanations can be put forward. First, the growth effects
of digital technologies may be subject to threshold effects: a critical mass of
users, complementary infrastructure and skills may be required before
significant productivity gains materialize [6]. Second, there is a possibility
of digital infrastructure using complementary channels to human capital instead
of as a standalone driver [7]. Third, the measurement problem, the
multicollinearity of the regressors or the relatively small effective sample
size for some of the regressors may mask true long-term relationships. Fourth,
structural constraints unique to Burkina Faso, such as the landlocked
geography, climatic exposure, security issues, and institutional constraints,
can dampen the impact of digital and health gains on sustained growth. Most
studies that examine the growth effects of information and communication
technology (ICT) or human capital in Africa employ panel techniques that
average effects across countries [8,9]. Evidence from country-specific
time-series is still limited, especially for the Sahelian economies This study
fills this gap by systematically exploring the long run and short run
relationships of the study variables between 1996 and 2024 by employing the ARDL
method.
Research
objectives
The
general objective of this study is to examine the impact of digital
infrastructure and human capital development on economic growth in Burkina Faso
during the period 1996–2024.
The
goals of the specific objectives are as follows:
· To investigate the time-series properties
of real GDP per capita, mobile cellular subscriptions, internet usage, life
expectancy at birth and gross fixed capital formation, and to determine their
orders of integration.
· To test for a long run cointegration
relationship between these variables using ARDL bounds-testing procedure.
· To estimate the long-run elasticities of
real GDP per capita with respect to mobile cellular subscriptions, internet
usage, life expectancy at birth and gross fixed capital formation.
· To investigate the short-run nature of the
relationship and to estimate the rate of convergence to the long run
equilibrium through the error-correction mechanism.
· To check statistical adequacy of the
preferred model using all available residual diagnostic tests and to verify
stability of estimated parameters using CUSUM and CUSUM of Squares procedures.
These
goals aim to progress systematically from data characterization to
cointegration testing to estimation of long-run and short-run effects, with a
final outcome that is statistically sound.
Research
hypotheses
Drawing
on the theoretical literature on augmented neoclassical growth, endogenous
growth, health capital and general-purpose technologies, the study formulates
the following testable hypotheses [10-15]:
· H1: There exists a
long-run cointegrating relationship among real GDP per capita, mobile cellular subscriptions, internet usage, life expectancy at birth and gross fixed capital
formation in Burkina Faso.
· H2: Mobile cellular
subscriptions exert a positive and statistically significant long-run effect on
real GDP per capita.
· H3: Internet usage
exerts a positive and statistically significant long-run effect on real GDP per
capita.
· H4: Life expectancy
at birth exerts a positive and statistically significant long-run effect on
real GDP per capita.
· H5: Gross fixed
capital formation exerts a positive and statistically significant long-run
effect on real GDP per capita.
· H6: The
error-correction term is negative and statistically significant, indicating
that deviations from the long-run equilibrium are systematically corrected over
time.
These
hypotheses guide the empirical analysis and provide clear criteria for
evaluating the results of the bounds test, the long-run coefficient estimates
and the error-correction model.
Significance
of the study
From
an academic perspective, this study contributes to the literature by providing
one of the few pure time-series ARDL analyses that jointly examines digital
infrastructure and health capital in a Sahelian economy. Previous research
mostly uses panel data techniques that make implicit the assumption of slope
homogeneity across countries. The single-country approach used here provides
estimates which are specific to the structural and historical conditions of
Burkina Faso and is consistent with current best practice in applied
time-series econometrics. From a practical perspective, the findings offer
evidence that can inform the prioritization of development interventions in
Burkina Faso. Additionally, a significant long-run impact on life expectancy
would support the long-term investment in public health [16]. Limited
significance of the digital infrastructure variables would suggest the need for
complementary policies such as digital skills development, electricity access
and regulatory improvements.
Scope
and limitation of the study
This
study focuses exclusively on Burkina Faso and covers the period 1996–2024. The
analysis looks at the relationship between real GDP per capita and the four
explanatory variables used: mobile cellular subscriptions, internet use, life
expectancy at birth, and gross fixed capital formation. There is no measure of
education indicators. Education indicators are not considered; only life
expectancy. The main limitations include the relatively small sample size
(approximately 29 annual observations), sparse early data on internet usage
that required limited interpolation, possible multicollinearity among the
digital and capital variables, and the single-country focus, which limits
generalization to other Sahelian economies.
Organization
of the study
The
rest of the study is divided into four chapters. Chapter 2 summarizes the
current theoretical and empirical literature on the subject of digital
infrastructure, human capital and economic growth; outlines the key gaps in
current analytical literature; and connects the current research with the
existing literature. The theoretical framework is then elaborated in chapter 3,
the empirical model is defined, the data sources and the definitions of the
variables used are explained, and the ARDL bounds-testing procedure and its
corresponding diagnostic and stability tests are explained. The results of the
empirical analysis are presented in order: descriptive statistics, unit-root
tests, lag selection, bounds testing, long-run elasticity, error-correction estimates,
residual diagnostics and parameter stability, with detailed interpretation.
Chapter 5 provides a summary of the key findings, details the theoretical and
empirical contributions of the study, provides policy recommendations,
recognizes research limitations and recommends future research.
Definition
of key terms
For
clarity, the principal terms used throughout the study are defined as follows:
Economic
growth is defined as sustained rise in real GDP per capita which is the key
indicator of the increase in average living standards and aggregate labour
productivity [17].
Digital
infrastructure: The physical and organizational systems that enable digital
communication and information exchange, proxied in this study by mobile
cellular subscriptions per 100 people and the percentage of individuals using
the Internet.
Human
capital development: Development of knowledge, skills and health of the
population which increases labour productivity. Life expectancy at birth is
used as an indicator of health capital in this study, and is considered a
summary indicator of human capital.
Physical
capital formation: Gross fixed capital formation as a percentage of GDP.
Long-run
relationship (cointegration): When two non-stationary variables are related in
such a way that deviations from the relationship are only short term.
Error
correction mechanism: This is a process in which short-run deviations from a
long-run cointegrating relationship are gradually eliminated, which is
expressed by the coefficient of the lagged error correction term.
These
definitions ensure consistency of interpretation across the theoretical,
methodological and empirical chapters that follow
Theoretical
framework
The augmented
neoclassical growth framework
The
foundational architecture for analyzing aggregate production dynamics
originates from the neoclassical model of Solow and Swan and was later
supplemented by Mankiw, Romer, and Weil. The augmented Solow framework relaxes
an assumption of purely exogenous technological progress and physical capital
accumulation, and allows for the inclusion of human capital (H) as a factor of
production separate from physical capital (K) and raw labor (L). The aggregate
production function is written as:
where
it is assumed that ?+? < 1 so that the aggregate production function
exhibits diminishing returns to the reproducible factor of production, which is
the capital stock K. In this context, human capital (including the level of
formal education and health capital, measured as a simple aggregate of the
health of workers) is a direct contributor of making workers more efficient and
of increasing overall output.
Endogenous growth theory
and knowledge spillovers
In
contrast to the neoclassical convergence prediction is that growth should level
off once a certain level of human knowledge is reached, endogenous growth
theory and the work of Lucas and Romer suggest that the accumulation of human
capital creates positive externalities, which offset the decline in the
marginal productivity of capital. Lucas highlights two types of impacts of
human capital: the impact of human capital on private productivity, through the
investments made by individuals in acquiring skills; and the impact of the
human capital stock on the overall efficiency of all production factors in the
economy, through the contribution of individual levels of human capital.
The health capital model
Health
as a core component of human capital is formally conceptualized by Grossman.
Grossman's approach conceptualizes health as a durable capital stock (H_t)
producing healthy time as an output. The stock of health capital depreciates
over time at rate ?t and can be augmented through gross investments (I_t) in
healthcare, nutrition, and environmental infrastructure:
Improvement
in health outcomes (typically measured by life expectancy at birth) increase
overall labor productivity, diminish absenteeism, and extend the economic lives
over which people can realize returns on education and skills, leading to
increased domestic saving and capital accumulation.
Digital infrastructure as
a general-purpose technology (GPT)
The
theoretical connection between digital telecommunications infrastructure and
aggregate economic performance is based on the General-Purpose Technology (GPT)
framework that Bresnahan and Trajtenberg have proposed. Digital
infrastructure—optical fiber networks, secure broadband servers, mobile
cellular coverage and high-speed Internet access—has three key characteristics:
Pervasiveness:
It spreads into virtually all sectors of the economy.
Continuous
Improvement: Its cost falls and functionality expand rapidly over time.
Innovational
Complementarities: It triggers technical innovations and business model changes
downstream.
Digital
infrastructure cuts the cost of searching for information, transactional costs,
and information asymmetries in markets, thus increasing total factor
productivity (TFP). In addition, human capital resources are also connected
synergistically with digital connectivity. High speed broadband amplifies the
productivity of skilled workers by making it possible to work remotely, access
e-learning services, provide financial inclusion through digital banking, and
provide the knowledge and information products in real time across regional
market centers.
Human capital
accumulation and economic growth
Empirical
measures of human capital are based on two main components: education and
health. Mankiw found that differences in GDP per capita across countries are
significant and can be accounted for by the rate of educational enrolment and
the level of physical capital accumulation. In the developing regions,
Donou-Adonsou confirmed that an increase in secondary and tertiary education
qualifications leads to a greater absorption of modern technologies, resulting
in positive long-term growth effects. With respect to the health aspect, Avci
and Caliskan applied the bounds test methodology of Autoregressive Distributed
Lag (ARDL) and validated the existence of a positive and statistically
significant long-run relationship between life expectancy at birth and GDP
performance. Following these results, Sultana examined the effect of life
expectancy gains on macroeconomic productivity for a dynamic panel of 141
countries, taking into account the endogeneity of the life expectancy variable,
and found that such gains have a lasting positive impact on macroeconomic
productivity. Likewise, at the microeconomic level Siri and Combary showed that
investments in health and human capital produce non-linear income gains when
combined with access to productive physical assets [18].
Digital infrastructure
and aggregate productivity
The
macroeconomic impacts of digital infrastructure growth have been a wide-ranging
area of study that has been assessed in a variety of panel datasets.
Donou-Adonsou examined 47 Sub-Saharan African economies by applying dynamic
panel estimators and concluded that the growth effect of internet adoption was
around four times stronger than the growth effect of mobile cellular adoption,
because of its wider usage in business automation. Calderon and Cantu
established that the effects of digital infrastructure on aggregate output are
mediated by two main channels: mobile connectivity primarily through TFP
productivity gains, and broadband Internet primarily through the process of
capital accumulation and structural change. Empirical studies of the past few
years have pointed to the threshold effects and structural complementarities of
digital infrastructure investments. Dah applied a System GMM estimator to
African panel data from 2000 to 2021, revealing a non-linear interaction
between human capital and the digital economy. Their research shows that a
minimum level of human capital is required for a successful outcome of digital
investments in terms of sustainable growth of the macroeconomy. Moreover, Osei
found that technological innovation and the complexity of agricultural exports
primarily occur through a boost in human capital capabilities and the adoption
of technologies in a region's local economy due to the build-up of digital
infrastructure.
Synthesis and
identification of literature gaps
Although
the empirical literature provides significant insights into the effects of
human capital and digital infrastructure separately on economic growth, there
are important analytical gaps:
· Methodological Inconsistencies: Many
cross-country panel studies use static estimators (Fixed Effects or Random
Effects) or standard System GMM estimators, without appropriately addressing
the possible non-stationarity, and long-run equilibrium processes across time
series.
· Lack or exclusion of Joint Synergies:
Empirical studies often measure human capital and digital infrastructure
separately, without taking into account their interactive effects.
· Regional Heterogeneity: Multi-country
panel often assume uniform slope parameters in heterogeneous economies (even
though the slope parameters without recognizing country-specific structural
features.
This
study directly contributes to the literature by implementing a pure time-series
ARDL modelling approach to Burkina Faso, for the joint analysis of digital
infrastructure, human capital and physical capital while distinguishing
long-run equilibrium relationship from short-run adjusted dynamics.
Theoretical
framework and model specification
This
study is theoretically based on augmented endogenous growth theory and modern
extensions of the neoclassical Solow-Swan growth theory. Standard neoclassical
growth models assume that aggregate national output is a function of the amount
of physical capital, the amount of labor input and the exogenous factor that
captures total factor productivity (TFP) or technological progress. Endogenous
growth models show, however, that economic production and long-term growth per
capita are determined by non-rival, knowledge-based assets, structural
efficiency gains and continuing capital accumulation. Information and
Communication Technology (ICT) infrastructure is a general-purpose technology
(GPT) in the modern digital economies. It reduces transaction costs, increases
market efficiency, accelerates the diffusion of knowledge and increases the
overall factor productivity of both the economy and all sectors. At the same
time, investments in human health and physical infrastructure create
institutional and productive capacity to effectively incorporate digital
innovations.
The
empirical specification in the log-linear form is given by:
Bounds
testing procedure for cointegration in a pure time-series setting
The
bounds-testing method of Pesaran, Shin and Smith are suitable for the present
investigation because it is a single-country time series for the period 1996 to
2024 that needs to be analyzed. The ARDL model estimation is presented in an
unconstrained error-correction form, which is the starting point for the bounds
test. Let lnGDPPCt be the natural log of real GDP per capita, lnMCSt be the
natural log of the number of mobile cellular subscriptions per 100 people,
lnIUIt be the natural log of the percentage of people using the Internet,
lnLEBTt be the natural log of life expectancy at birth, and lnGFCFt be the
natural log of gross fixed capital formation as a percentage of GDP. The
unrestricted ARDL equation in first difference form is given by:
Where
? is the first-difference operator, p, q_1, q_2, q_3, q_4 are the respective
lag orders, ?0 is the intercept, and ?t is assumed to be a white-noise process.
The Akaike Information Criterion (AIC), and the maximum length chosen does not
include too many degrees of freedom as the sample size is relatively small,
about twenty-nine annual observations.
The
bounds test only looks at the significance of the combination of the lagged
level coefficients. The null hypothesis for the absence of long run levels
relationship (no cointegration) is:
while
the alternative hypothesis asserts that at least one of the ? coefficients is
different from zero. The asymptotic distribution of the Wald or F-statistic is
non-standard under the null. Pesaran therefore supply two sets of asymptotic
critical values: a lower-bound critical value that assumes all regressors are I
(0) and an upper-bound critical value that assumes all regressors are I (1). If
the computed F-statistic lies above the upper bound, the null of no
cointegration is rejected irrespective of the true integration orders of the
regressors. If the statistic is less than the lower number, the null is not
rejected. We have a region that lies between the two bounds that we cannot
determine the value of the function. Given the limited sample size in the
present study, the finite-sample critical values tabulated by Narayan are also
referenced to prevent inference from being skewed by the use of asymptotic
critical values [19].
Once
the existence of a level’s relationship has been established, the long-run
elasticities are recovered by normalizing the lagged level coefficients on the
coefficient of the lagged dependent variable:
The
normalized coefficients are the complete percentage change in real GDP per
capita for a one percent change in each of the explanatory variables, assuming
all short-run adjustments have taken place, while the other variables remain
unchanged. Then the error-correction term is formed as a linear combination of
the lagged levels
Substitution
of this term into a restricted error-correction model yields the short-run
dynamics:
Selection
of optimal lag length and model specification search
The
selection of the length of the lag is a crucial intermediate step between the
unit-root test and the bounds test. An under-parameterized model risks
omitted-variable bias and residual serial correlation, while an
over-parameterized model quickly has to use up the precious degrees of freedom
and may yield vague estimates. In the present application, the maximum lag
length is set to four, a typical value for annual data with sufficient number
of observations after differencing and lagging. All possible ARDL
specifications are estimated from this maximum and then ranked based on the
Akaike Information Criterion. A more parsimonious alternative is calculated
parallel to the Schwarz Bayesian Criterion. If the two criteria agree on the
order of lag, that order is chosen; if they disagree, the one selected is based
on residual diagnostics (especially lack of serial correlation) and statistical
significance of the highest-order lag coefficients
Interpretation
of the error-correction term
Furthermore,
the value of ? can be directly interpreted economically. A minus sign of, say,
–0.35 means that about 35 per cent of the gap from the long run growth path is
closed in one year, making the half-life of a shock about two years. This kind
of data has significant policy implications: it can suggest how fast the
Burkinabè economy will recover to its equilibrium growth path following a
short-term interruption in investment in the digital infrastructure, health
consequences, or investment in physical infrastructure.
Residual
diagnostics and model adequacy
The
ARDL–ECM specification should pass a set of diagnostic tests of the residuals.
The Breusch–Godfrey Lagrange-multiplier test is used to test for serial
correlation, preferred to the Durbin–Watson statistic due to the latter being
biased in the case of lagged dependent variables. Heteroskedasticity is
examined with the ARCH test (which uses an autoregressive conditional
heteroskedasticity test) and the White test (which is general test of
heteroskedasticity that is robust to unknown forms of heteroskedasticity). The
Jarque–Bera test is used to assess the residual normality; the null hypothesis
of the Jarque–Bera test is that the residuals come from a normal distribution.
The Ramsey RESET test is used to test for functional-form misspecification, by
including powers of the fitted values in the original equation and testing the
joint significance of them. Finally, influential observations or outliers are
explored using leverage statistics and studentized residuals.
Robustness
exercises and alternative specifications
A
series of robustness checks are carried out within the ARDL–ECM framework.
These include: (i) alternative lag structures around the preferred AIC
specification, (ii) the addition of a linear deterministic trend, (iii)
splitting the sample around 2010, (iv) the inclusion of dummy variables for
possible structural breaks, and (v) the sequential exclusion of control
variables. All the checks are kept within the single-equation ARDL–ECM approach
with the AIC lag selection criterion.
Variable
definitions, measurement, data sources and theoretical justification
Empirical analysis is based on all data available for Burkina Faso for the 1996-2024 period, all of which are annual observations. The starting year is determined by the first year to have consistently available digital-infrastructure indicators, and the ending year is that with the latest published indicators at the time of writing. The principal source is the World Bank's World Development Indicators (WDI) database, which offers internationally comparable series, based on standard methodologies (Table 1). The theoretical hypotheses for these explanatory variables are a-priori clear: all four variables are hypothesized to enter into the long-run equation with a positive sign. However, the size of the elasticities is up to an empirical question. Specifically, the relative size of the elasticities of the human-capital and physical-capital to the digital-infrastructure will characterize whether the growth process in Burkina Faso has already started to move toward knowledge- and connectivity-based sources of productivity improvement.
Econometric
strategy: sequence of estimation and inference
The
empirical strategy unfolds in a carefully ordered sequence designed to ensure
that each subsequent step rests on a statistically secure foundation. The first
stage consists of a thorough examination of the time-series properties of the
five logarithmic variables. Augmented Dickey–Fuller, Phillips–Perron, and KPSS
tests are applied both to the levels and to the first differences, with lag
lengths selected by the AIC and with alternative assumptions concerning the
deterministic components (intercept only, intercept and trend). The objective
is to establish that every series is I(1) and that none is I(2). The second
stage is the selection of the optimal lag structure for the unrestricted ARDL
model, as described in section 3.3. The third stage is the formal bounds test
for the existence of a long-run levels relationship. Only if cointegration is
confirmed does the analysis proceed to the fourth stage—the recovery of the
long-run elasticities and the estimation of the restricted error-correction
model. The fifth stage comprises the full suite of residual diagnostics and
parameter-stability tests. The sixth and final stage consists of the robustness
exercises outlined in section 3.8.
Results
and discussion
This
chapter presents empirical results of the ARDL–ECM applied to annual
time-series data for Burkina Faso ranging 1996 to 2024. The results are
organized according to the sequential estimation strategy outlined in Chapter
3. The discussion starts with descriptive evidence, proceeds through unit-root
testing and lag selection, the determination of the existence of a long-run
cointegrating relationship, and the reporting of the long run elasticities,
short-run dynamics, residual diagnostics and parameter-stability tests.
Throughout, the interpretation of the coefficients is always tied to the
theoretical structure outlined above and to the economy's particular structural
features of the Burkinabè economy.
Descriptive
statistics
Purpose
of the analysis
The
descriptive statistics are used to give a preliminary description of the
central tendency, dispersion, range and distributional shape of the five
variables used in the study. This step is crucial prior to formal unit-root
testing and ARDL estimation because it provides insight into the
characteristics of the data, identifies the data's potential non-linearities,
its outliers, and aids in subsequent logarithmic transformation and model
specification.
Presentation of Results
The mean, median, maximum, minimum, standard deviation, skewness and kurtosis for real GDP per capita, individuals using the Internet, life expectancy at birth, mobile cellular subscriptions and gross fixed capital formation for 1996 through 2024 (Table 2).
The results of the
statistics are explained
The
mean of real GDP per capita is 570.5 USD and the median is 561.8 USD with a
moderate standard deviation of 120.0 USD and nearly zero skewness of 0.11. Mean
of Internet usage is low (6.03 per cent), and median is much lower (2.40 per
cent), with high positive skewness (1.58) and high kurtosis (4.36). Life
expectancy has a mean value of 55.81 years, a low range (49.56–61.29) and the
lowest standard deviation (4.00). The mean of mobile subscriptions is 46.45
with a high standard deviation of 44.81 and slight positive skewness of 0.32.
Gross fixed capital formation has the least volatile series with the smallest
standard deviation of 2.83 and the smallest skewness (0.08) and is almost
symmetrically distributed.
Unit-Root
Tests
The
unit-root tests aim at establishing the order of integration of each time
series prior to estimating the ARDL model.
Presentation of Results
The
ADF test statistics and the associated p-values for the variables in levels and
first differences are reported in Table 2, and the inferred order of
integration is reported in the (Table 3).
Interpretation of the
Statistical Results
At
levels, the ADF statistics for all four variables are statistically
insignificant (p-values = 0.2859–1.0000), indicating failure to reject the null
hypothesis of a unit root. After first differencing, all variables become
statistically significant (p-values = 0.0000–0.0040), indicating stationarity.
Hence, there are no variables of order two, I(2), and all variables are
integrated of order one, I(1).
These
results provide the statistical basis for applying the ARDL bounds test
approach.
ARDL
bounds test for cointegration
The
purpose of the ARDL bounds test is to determine whether a statistically
significant long-run (levels) relationship exists among real GDP per capita,
mobile cellular subscriptions, internet usage, life expectancy at birth and
gross fixed capital formation.
Presentation of Results
Table 3 reports the computed F-statistic from the bounds test together with the critical value bounds at the 10 percent, 5 percent and 1 percent significance levels (Table 4). The computed statistic F is 6.2422, which is greater than the critical value I(1) at any conventional significance level, including the most severe 1 percent level (5.840). Thus, the null hypothesis is rejected as the result is very unlikely to be due to chance. The result corroborates the existence of a unique cointegrating vector among the five variables for the time period 1996 to 2024. The bounds test provides statistical support for the study’s central hypotheses by validating a stable long run equilibrium between digital infrastructure, human capital, physical capital and real GDP per capita.
Long-run
coefficients
The
purpose of estimating the long-run coefficients is to quantify the equilibrium
elasticities of real GDP per capita with respect to life expectancy, internet
usage, mobile cellular subscriptions and gross fixed capital formation once
cointegration has been established. These elasticities represent the percentage
change in real GDP per capita resulting from a one percent change in each of
the explanatory variables, holding the others constant.
Presentation of Results
Table 4 reports the long-run elasticities derived from the ARDL levels relationship, together with their standard errors, t-statistics, p-values and statistical decisions (Table 5). Only life expectancy at birth (LEBT) and the constant term are statistically significant at the 5% level in the long-run equation. Internet use (IUI), mobile cellular subscriptions (MCS) and gross fixed capital formation (GFCF) are not statistically significant. This suggests that health capital contributes significantly to the dynamics of real GDP per capita in Burkina Faso over the long run, while digital infrastructure and physical capital do not have a statistically significant long-run relationship in the estimated model.
Economic Meaning
The
important positive impact of life expectancy reinforces the health-capital
framework of Grossman and the macroeconomic theories of Bloom and Canning.
Support for the Study’s
Hypotheses
The
long-run results partially support the study's hypotheses. The hypothesis that
human capital (life expectancy) has a positive impact on economic growth is
supported, while the hypothesis regarding long run impacts of digital
infrastructure and physical capital formation are not statistically supported
for this specification
Short-run
dynamics & error correction model (ECM)
The
purpose of estimating the error-correction model is to examine the short-run
dynamics of real GDP per capita and to measure the speed at which the Burkinabè
economy adjusts back to its long-run equilibrium after a shock (Table 6). The
negative coefficient of the lagged error-correction term suggests that the
error-correction effect takes about half a year to complete, and around 50.61
percent of any error from the long-run equilibrium is corrected within one
year. This is a rather quick speed of adjustment. The short-run coefficient on
life expectancy is statistically insignificant, meaning that its effect on real
GDP per capita is not detectable in the same year as it changes, once the
long-run relationship is considered. The significant error-correction term
confirms the existence of a stable long-run equilibrium, while the
insignificant short-run effect of life expectancy suggests that the influence
of health capital operates primarily through long-run channels.
Summary
of model and residual diagnostic checks
The
residual diagnostic and parameter stability tests aim at confirming that the
estimated ARDL error correction model is statistically acceptable and that the
model's parameters are stable for the sample period. Satisfactory diagnostics
of residuals ensure validity of standard inference, and the CUSUM and CUSUM of
Squares tests ensure that the long run and short run parameters are stable and
free from possible structural breaks that could affect the results (Table 7).
All
of the standard diagnostic tests are fulfilled at the conventional significance
level in the model. There is no serial correlation as indicated by the
Breusch–Godfrey LM test and no heteroskedasticity as shown by the
Breusch–Pagan–Godfrey test. There is no first order autocorrelation as well,
indicated by the Durbin-Watson statistic. The CUSUM and the CUSUMS of the
square’s plots are both within the 5% critical bands, and the parameters are
stable across the sample, although there is a minor small change in the
residual variance in the middle of the sample that is not statistically
significant (Figure 1).
Summary
of key findings
This
study examined the effects of digital infrastructure and human capital
development on economic growth in Burkina Faso over the period 1996–2024 using
the ARDL bounds-testing approach. The empirical results show that all variables
are integrated of order one, I(1), and that a long-run cointegrating
relationship exists at the 1% significance level. Among the explanatory
variables, only life expectancy at birth, as a proxy for human capital, is
statistically significant in the long run, whereas internet usage, mobile
cellular subscriptions, and gross fixed capital formation are not. The
error-correction term is negative and statistically significant, indicating
that approximately 50.61% of short-run disequilibrium is corrected within one
year, implying a relatively rapid adjustment toward the long-run equilibrium.
Diagnostic tests show no evidence of serial correlation or heteroskedasticity,
and CUSUM and CUSUM of Squares tests suggest that the parameters do not change
over the sample period. Overall, the results indicate that human capital,
measured in life expectancy at birth, has the most significant long-run effect
on economic growth in Burkina Faso, as measured by the variables considered,
while the effects of digital infrastructure and physical capital formation are
not statistically significant in the preferred specification. The results
suggest that the impact on health outcomes is more closely linked to economic
growth in the long-term than simply to the digital infrastructure, emphasizing
the need for complementary investments in human capital to extract the growth
potential of digital development.
Theoretical
and empirical contributions
This
study makes three important contributions to the literature. First, it provides
one of the few single-country time-series analyses examining the joint effects
of digital infrastructure and human capital on economic growth in a Sahelian
economy. Unlike most existing studies, which rely on multi-country panel data
and assume slope homogeneity, this study captures country-specific dynamics in
Burkina Faso. Second, it implies the ARDL bounds-testing approach,
incorporating appropriate lag selection, residual diagnostics and parameter
stability tests, thereby addressing common methodological challenges associated
with time-series data developing economies. Third, the findings qualify the
widely held view that digital infrastructure independently promotes long-run
economic growth. While human capital, measured by life expectancy, exerts a
significant long-run effect, internet usage, mobile cellular subscriptions and
physical capital formation do not exhibit statistically significant independent
long-run effect in the preferred specification for Burkina Faso between 1996
and 2024 [20-36].
Based
on the empirical findings, the following recommendations are proposed:
Increase long-term
investment in health capital.
Given
that only life expectancy has a significant long-run impact on real GDP per
capita, the government needs to focus on programmers’ that enhance the health
of the population, such as an expansion of primary healthcare, a decrease in
infant and maternal mortality rates, nutrition and vaccination.
Create complementary
conditions for Digital Infrastructure
Although
mobile subscriptions and internet usage are not individually significant in the
long run, their expansion remains important. Digital investments should be
supported by improved electricity access, digital skills training, affordable
data, and a conducive regulatory environment.
Increase quality and
efficiency of physical capital investment
Priority
should be placed on enhancing the quality, efficiency and productivity of
public and private investments, especially in human capital and digital
transformation.
Follow an integrated
growth approach.
There
is a need for coordinated policies that will advance health outcomes,
productive investment and meaningful digital access.
Suggestions
for Future Research
Future
research could incorporate education-based measures of human capital (such as
secondary or tertiary enrolment rates), test interaction terms between digital
infrastructure and life expectancy, and explore threshold or non-linear ARDL
models. Extending the time series with more recent data or conducting
comparative analyses with other Sahelian countries would further strengthen the
evidence base.
This
study finds a stable long-run relationship between digital infrastructure,
human capital, physical capital and economic growth in Burkina Faso. The
independent contribution of digital infrastructure is small in the current
specification, and life expectancy consistently drives real GDP per capita in
the long run. The relatively rapid speed of adjustment indicates that the
economy reacts systematically to deviation from equilibrium. These findings
underscore the central importance of health-capital accumulation for long-run
growth and the need for complementary policies to enhance the effectiveness of
digital and physical investments.