Construction and Seasonal Patterns of Islamic Hijri Calendar Monthly Time Series : An Application to Consumer Price Index ( CPI ) in Pakistan

Riaz Riazuddin

doi:10.12816/0004975

Abstract

Time series data are compiled and analysed in accordance with Gregorian calendar, given its world-wise use. This paper presents a simple method of constructing time series in accordance with Hijri Calendar from an already compiled Gregorian time series. Preliminary seasonal analysis of Hijri time series for CPI in Pakistan provides new insights of price behavior that depends both on Gregorian and Hijri seasonality. A spliced series of monthly CPI from January 1976 to December 2008 spanning 33 Gregorian years (396 Gregorian months) is used to capture a full cycle of 34 Hijri years (408 Hijri months). Method presented is general and can be used to construct and analyse any variable of interest. Paper proposes that statistical agencies and central banks of Islamic countries should also compile data according to Hijri Calendar, in addition to existing compilation according to Gregorian calendar. This will add to a better understanding of socioeconomic behaviours in Islamic countries.

Highlights

Time is one of the most important manifestations of existence in the universe and beyond
In this paper I present a simple method to construct a monthly time series of a variable according to Islamic Hijri calendar
Application of this method to consumer price index in Pakistan reveals some simple characteristics of Hijri time series which remain largely concealed under conventional Gregorian time series analysis

Summary

Introduction

Time is one of the most important manifestations of existence in the universe and beyond. Business and economic time series are only available in Gregorian calendar and analyses of socioeconomic and business trends are restricted to this calendar This does not necessarily constrain the evolution of knowledge in western societies where socioeconomic behaviours are mostly secular or influenced by Christian tradition. In Islamic societies, the analysis of time series within Gregorian calendar conceals many important aspects that are profoundly influenced by Islamic tradition and Hijri calendar. In this paper I present a simple method to construct a monthly time series of a variable according to Islamic Hijri calendar. Application of this method to consumer price index in Pakistan reveals some simple characteristics of Hijri time series which remain largely concealed under conventional Gregorian time series analysis. Final section concludes and presents some suggestions for the way forward in Hijri time series analysis

Section 1: Gregorian Data and Method of Transformation to Hijri Calendar

Findings

H6 H7 H8 H9