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IPS155 Stefan B. et al.
security level (e.g. ISIN). For analysis and research purposes it is often
necessary to combine microdata from different sources or policy domains
using these identifiers.

The item "Unit Descriptions" provides information about available
identifier(s) in the dataset. More than one
identifier is allowed, separated by a comma. Identifiers from external data
vendors are allowed.
Example: Bank ID, ISIN

Descriptions: The purpose of the metadata item “Descriptions” in the
INEXDA schema is twofold.
1. It provides a short description of the dataset.
2. It is used to share information about the scope of structural breaks
in the dataset, where structural breaks are defined as major events
and revisions that have impacted the dataset.
Designing a metadata schema for microdata needs to employ a
procedure documenting significant changes made to a dataset over time
stemming from a change in underlying reporting requirement rules. These
structural breaks, if they occur, affect metadata items in that the appropriate
documentation becomes time dependent. For example, the reporting
frequency of a dataset changes in 2012 from quarterly to monthly. In the
INEXDA metadata schema the item “Temporal Coverage” will now depend
on the time period: before 2012 the appropriate value is quarterly, after the
structural break in 2012 the value is monthly.
Besides changes to the time frequency with which data is collected, other
examples of structural breaks include:
• Changes to the set of collected variables.
• Changes in the population or sampling.
Example:
The SHS-Base is the core module of the Deutsche Bundesbank’s Securities
Holdings Statistics (WpInvest). The motive behind creating the SHS-Base is to
be able to answer the question: “Who holds what from whom and how
much?”. Financial institutions domiciled in Germany report securities which
they hold for domestic or foreign customers (“custodian-approach”). In
addition, domestic banks provide information about their own holdings,
irrespective of where the securities are held. Reporting agents are domestic
banks (monetary financial institutions excluding money market funds),
domestic investment companies and “other” domestic investment
companies. The SHS-Base is collected by means of a full census, i.e. every
reporting agent has to send a report (if no securities are held in safe custody,
a nil report is filed). The reporting agents provide information on securities

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