Chapter 5

Analysis of historical price data

5.1 Introduction

Reviewing historical price data is essential in understanding current price behavior.

Combining price data with contextual information about agricultural production,

consumption, and marketing will improve monitoring an analysis.  Issues such as price data

coverage, defining seasonal patterns, analysis of particular markets and commodities, and

specific case studies will be discussed in this chapter.

5.2 Review historical price data

5.2.1 Data Coverage

The first step in reviewing price data is to review what data are actually available. The

identification of the data coverage refers to a systematic examination of what data actually

exist for different commodities and markets.  Within 

Priceman

, there is a simple process 

guided by a step by step help wizard to assist the analyst.  The output is a matrix of the

number of valid months of data for each market commodity combination by year (Figure

5.1).  This is an efficient and rapid method to examine the data coverage. This examination

will in combination with the output from the worksheets, studies, and expert knowledge 

set boundaries of what analysis is possible.

Figure 5.1:  Priceman output of the data coverage operation

Data Coverage by Months.

The numbers represent the number of valid Months.

Country|Market|Source

Commodity

1993

1994

1995

1996

1997

ZA|LUSAKA URBAN|AMIC MAIZE

0

1

12

12

4

ZA|LUSAKA URBAN|AMIC MAIZE DRY 90 KG

6

11

12

12

4

ZA|MONGU|AMIC

MAIZE

0

8

12

12

4

ZA|MONGU|AMIC

MAIZE DRY 90 KG

8

11

12

12

4

ZA|NDOLA|AMIC

MAIZE

0

10

12

12

4

ZA|NDOLA|AMIC

MAIZE DRY 90 KG

6

11

12

11

4

30