In this first tutorial we will take a brief look at accessing data from the EconData app. The picture below shows the data query menu. EconData queries work by filtering out time series using a data key.
Before we get into the data key in further detail, we must first select the data flow (think data set for simplicity) we are interested in. In this case we select Market rates. This selection will load the relevant releases and data key for this data set.
The releases refer to the vintage of data we are interested in. We have selected Unreleased which will be the newest, most up-to-date data not necessarily contained in the last release. If no selection is made manually, the latest release will be returned.
Now to get back to the data key. Each time series has a unique data key (note that, in general, a data key can also reference many time series). The data key is created by the joining of the various time series dimensions for a particular data set with a period separating each dimension.
For example, the data key
CMJD002.B.A, references the average daily bond yield with a maturity of 3-5 years. It is of the form
Mnemonic.Frequency.Aggregation, which can be seen from the data key section in the image above (given as descriptions instead of enumerated codes).
By leaving out a dimension we are implicitly requesting all of the available enumerations for that dimension. This is what is happening in the above query where Frequency and Aggregation have been left unspecified (the data key is effectively
Although this seems complex, it is quite easy once you get the hang of it and it comes with the benefit of being quite powerful. By stringing together time series dimensions in this way it is possible to succinctly reference thousands of series.
Once we are happy with the time series we are filtering we submit the query. Below is part of the table that the query returns.
Finally to download the data we click Export. We can select the format we would like, in this case we have selected to download the file in Excel format. Also included, is a one-liner that can be used with the EconData R package in order to automate the query in future instances, but more on that next time…
Byron Botha – Co-founder and Data Scientist at Codera Analytics