What is time series data?
The title of this section may seem a little odd. Is time series data somehow different from other sorts of data? The answer is yes. Look at the time series plotted in Figure 6.1. It is a plot of the UK’s monthly seasonally adjusted unemployment rate from February 1971 to December 2019 inclusive. The unemployment rate (percentage) is for all individuals aged 16 and over. I have taken the data from UK’s Office of National Statistics website – see point 2 in the Notes and further reading section. The data is publicly available and regularly updated.
Figure 6.1: Monthly UK seasonally-adjusted unemployment rate (percentage)
The key here is the time aspect of the data. Each data point in a time series dataset is associated with a particular time point. This introduces two new key aspects to the data:
- There is a natural ordering to the data, that is, we can order the data points by the timepoint, and...
