TITLE:
Interrupted Time Series Analysis of Military and Civilian Regimes in Nigeria: A Statistical Evidence from Gross Domestic Product (GDP)
AUTHORS:
Desmond Chekwube Bartholomew, Geoffrey Uzodinma Ugwuanyim, Ukamaka Cynthia Orumie, Francis Attah Egwumah
KEYWORDS:
ARIMA, Forecast, Gross Domestic Product, Nigeria, Intervention, Interrupted Time Series
JOURNAL NAME:
Open Journal of Statistics,
Vol.13 No.4,
August
30,
2023
ABSTRACT: Governments
influence the economy by changing the level and types of taxes, the extent and
composition of spending, and the degree and form of borrowing. Governments
directly and indirectly influence the way resources are used in the economy.
Higher taxes, fees, and greater regulations can stymie businesses or entire
industries and the resulting impact is reflected on the country’s economy status
(strong or weak). The growth rate of GDP is often used as an indicator of the
general health of the economy. In broad terms, an increase in real GDP is
interpreted as a sign that the economy is doing well. So it is important to
study and pay more attention to country’s GDP growth rate. In this paper, an
intervention analysis approach was applied to Nigeria GDP data in order to
evaluate the performances of military and civilian rules in the country. Data
on Nigeria GDP were collected and subjected to interrupted (intervention) time
series model. Based on the Alkaike Information Criterion (AIC), Bayesian
Information Criterion (BIC) and sigma2 values, the interrupted time
series model ARIMA (1, 1, 0) with exogenous variables (per capita per capita GDP, intervention,
year and yearAfter) was identified as the best model amongst other competing
models. It was observed that the intervention (civilian rule) was significant
at the 10% level of significance in increasing the Nigeria GDP by 10B US$ on
the average since 2005 till 2021 while controlling for the effects of other
determinants. Also, the ARIMA (1, 1, 0) forecasts indicate that the Nigeria GDP
will continue increasing during the civilian rule. As a result, changing from
military rule to civilian rule in Nigeria significantly increased the GDP of
the country.