The ECB requires credit institutions to hold compulsory deposits on accounts with the national central banks: these are called “minimum” or “required” reserves. The amount of required reserves that each credit institution has to hold is determined by its reserve base multiplied by a minimum reserve ratio.

One of the Bundesbank's tasks is to collect monetary, financial and external sector statistical data, comprehensive sets of indicators and seasonally adjusted business statistics. For macroeconomic analysis relevant data are then fed into the macroeconomic time series published in the time series databases.