Time Series Intervention Modelling Based on ESM and ARIMA Models: Daily Pakistan Rupee/Nigerian Naira Exchange Rate
Elisha J. Inyang *
Department of Statistics, University of Uyo, Uyo, Nigeria.
Ette H. Etuk
Department of Mathematics, Rivers State University, Port Harcourt, Nigeria.
Ngia M. Nafo
Department of Mathematics, Rivers State University, Port Harcourt, Nigeria.
Yvonne A. Da-Wariboko
Department of Mathematics, Rivers State University, Port Harcourt, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
The battered Nigerian economy has slipped into its second economic recession in five years due to the fallout of the coronavirus pandemic. And this has had a remarkable effect on the value of the Nigerian Naira that are exchanged for a unit of many other currencies of the world. Intervention modelling is used to assess the impact of this external event on the Pakistan Rupee to the Nigerian Naira exchange rates. The dataset for this study is the daily Nigerian Naira exchange rate with respect to the Pakistan Rupee from January–December 2020. The intervention point is marked on April 10, 2020, as a pulse function for the PKR/NGN series. Results revealed that the economic recession due to the fallout of the coronavirus pandemic increased the value of the Nigerian Naira by 3.38% against the Pakistan Rupee, which 1PKR is exchanged for 2.2042NGN compared to the periods before and after the intervention occurred. The intervention was felt at the point of intervention itself but the effect dies immediately after the intervention. Hence, the intervention response is described as an abrupt start and abrupt decay.
Keywords: Time series intervention modelling, ESM, ARIMA, exchange rate, Nigerian Naira, Pakistan rupee