The EDSC offers several databases to get credit ratings. The most important differences are:
- Access: Getting data from Datastream is only possible at the Datateam pc’s in the Y03-17. Bloomberg terminals are available in Y03-18. ThomsonONE, Compustat and Mergent are accessible via from home.
- Geographical coverage: Compustat and Mergent only contain rating for American companies. ThomsonsonONE, Datastream and Bloomberg offer credit ratings worlwide.
- Historic: Mergent has data from 1950 onwards, Compustat thas data starts from 1973. Bloomberg from the beginning of the 80’s. ThomsonONE mid ninty’s. Datastream only contains current credit ratings.
- Identifiers: to get data from financial databases like Compustat and Datastream identifiers are needed, these are codes identifying e.g. a company, stock or bond. In Datastream one can use ISIN-, SEDOL- or DS-codes, in Compustat you need the CUSIP (9 digits) or Ticker symbol to retrieve the data.
- Update: CRSP is being updated once a year, while in Datastream and Bloomberg the stock prices up til yesterday can be found.