Aalto Finance Databases from your labtop: Wharton Research Data Services

WRDS is the place to go in case you want to work on from home. The way this works, is that you click the link and register as a Aalto user. After registration you will have to wait for approval. Once approved, you can access the data.  

Importantly, as time passes by, your access will get old. Please, do remember to renew your registration.

WRDS is an research platform that contains access to several databases, the most important ones being Compustat and CRSP. Compustat contain US company information such as income statements and balance sheets. CRSP contains US security prices.

WRDS is an umbrella or platform that actually contains several databases

To gain access to WRDS you need to do the registration. The picture below shows you how this is done.

Aalto Finance databases include WRDS, first you need to register

Once you have registered you need to learn the basics on how to use the database. This video should be helpful in getting started.

In many cases there is a need to combine data from both CRSP and Compustat. In this case common tickers should not be used. The reason for this is that one company may use several tickers in different time periods. Also, tickers are recycled, and same ticker may actually refer to two totally different companies.

Tickers should not be used to combine different data sets

Instead of tickers use the CRSP/Compustat Merged Linking Table. This table maps the Compustat identifier (GVKEY) of a company to the CRSP identifier (PERMNO) of that company.

To download the latest CRSP/Computat Linking Table:

  1. Go to WRDS Home → CRSP → CRSP/Compustat Merged → Compustat CRSP Link
  2. Select “Search the entire database”
  3. Keep the default linking options checked: LU and LC

See the Database Wiki for more information.