Research Article
Modelling the Dependency between Inflation and Exchange Rate
Using Copula
Charles Kwofie , Isaac Akoto, and Kwaku Opoku-Ameyaw
Department of Mathematics and Statistics, University of Energy and Natural Resources, Sunyani, Ghana
Correspondence should be addressed to Charles Kwofie; charles.kwofie@uenr.edu.gh
Received 26 March 2020; Revised 12 May 2020; Accepted 30 May 2020; Published 17 June 2020
Academic Editor: Aera avaneswaran
Copyright©2020CharlesKwofieetal.isisanopenaccessarticledistributedundertheCreativeCommonsAttributionLicense,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
In this paper, we propose a copula approach in measuring the dependency between inflation and exchange rate. In unveiling this
dependency, we first estimated the best GARCH model for the two variables. en, we derived the marginal distributions of the
standardised residuals from the GARCH. e Laplace and generalised t distributions best modelled the residuals of the
GARCH(1,1) models, respectively, for inflation and exchange rate. ese marginals were then used to transform the standardised
residuals into uniform random variables on a unit interval [0, 1] for estimating the copulas. Our results show that the dependency
between inflation and exchange rate in Ghana is approximately 7%.
1. Introduction
Macroeconomic variables such as inflation and exchange
rate are very fundamental in any country’s economy. ey
are the key indicators of performance of an economy as a
whole. Several studies have focused on showing the dy-
namics and dependencies between these macroeconomic
variables. According to the literature, inflation is of high
priority to central banks because it gives an indication of
price stability in an economy. Many argue that having high
inflation leads to lower savings of individuals and also
downplays an economy’s international competitiveness. On
the other hand, it is believed that a low inflation rate pro-
motes economic growth. Some ways in which governments
control inflation is by targeting exchange rates, interest rate
dynamics, and others.
e literature somehow provides different results when it
comes to the kind relationship between inflation and other
macroeconomic variables such as the exchange rate. ese
conflicting results in the relationship between inflation and
exchange rate differ with countries and data periods. Hence,
the exchange rate can be said to be linked to inflation rate
volatility through importation of goods and materials
needed for production. e dependency of macroeconomic
indicators has been shown in several papers to have some
existing relationship [1–3]. However, this relationship has
been unveiled using different approaches and methods. For
instance, Kwofie and Ansah [4] used the autoregressive
distributed lag (ARDL) model, while Arslaner et al. [1] used
Markov switching regression and vector autoregression
(VAR) methods in establishing some dynamics between
inflation and exchange rate.
We are motivated by the work of Barro and Gordon [5]
who pioneered and proposed an inflation and exchange rate
nexus in relation to credibility of the monetary policy. eir
argument was that any economy with a stable or fixed ex-
change rate regime has the tendency of lowering the inflation
by authorities’ increasing credibility. is assertion was
echoed in [6, 7]. ey both stated that having a stable
currency is not just a good step for maintaining inflation but
also enhances monetary policy efficiency.
Anthony and Nkegbe [8] studied the relationships be-
tween several macroeconomic variables in Ghana using
cointegration techniques. eir results showed a significant
relationship between inflation and exchange rate in Ghana.
Similarly, Gyebi and Boafo [9] stated in their conclusion that
the exchange rate and money supply are the main macro-
economic variables responsible for inflation changes in the
Ghanaian economy. Nortey et al. [10] stated that one of the
main aims of Ghana’s central bank is to maintain stability in
Hindawi
Journal of Probability and Statistics
Volume 2020, Article ID 2345746, 7 pages
https://doi.org/10.1155/2020/2345746