Time series of index relatives
ID:CVTIR

Video Overview

Time series allow us to analyse data that has been collected over a period of time.  When this data is on prices or volumes, it can be difficult to make comparisons due to inflation, changes in demand, or changes in supply.  What we need is a single figure that shows how much one year differs from another.  A simple way of doing this is to take a reference point, or a base year, and express the figures for other years relative to this.  A single figure that summarises a comparison between two or more sets of figures is called an index number. There is a type of index number known as the percentage relative index. This is also referred to as the price relative, and was discussed in the previous tutorial. In this tutorial we will look at other types of index numbers that can be used to identify the percentage change in a series over time, rather than just the level of the series at a point in time.