Please help. I can't find any linking tables / databases to merge CRSP and Compustat data

[Tahseen Hasan]

I scoured through every forum, WRDS and Google pages but all I find is SAS codes to merge the dataset but no information on where I can actually obtain the linking table.

I'm hoping to match PERMNO / PERMCO (which variable is more preferable to use?) data from CRSP, to GVKEY data from compustat.

I'm at my wits end at this point and I spent the whole night looking for this mythical table. Any help would be very appreciated

[David Benson]

Tahseen Hasan This comes up often enough that I pulled together some resources. Hopefully one of these will help.

Also, I think PERMCO will be your better identifier:

PERMCO: A unique permanent company identification number assigned by CRSP to all companies with issues on a CRSP file.

PERMNO: A unique permanent identification number assigned by CRSP to each security.

I know this is an older thread, but given that merging daily / monthly stock return data from CRSP to annual accounting data in COMPUSTAT, I thought I would pull together some helpful links.

If you have access to the Compustat-CRSP merged (CCM) database, they have done all the hard work of matching CRSP's PERMNO's to Compustat's GVKEY's (and matching up the dates.) No merging needed.

If like many of us, you don't have access (so you have to match them manually), Robson Glasscock's blog "Stata and Accounting Research" here has a number of useful entries. In particular see:

1. Merging CRSP and Compustat data (which itself points to a number of other helpful CRSP / COMPUSTAT resources
2. Dealing with GVKEY and DATATADATE (FYEAR) duplicates in Compustat in Stata

Rui Dai has a very helpful tutorial about CUSIP, GVKEY, PERMNO, ticker, etc as well as linking CRSP / Compustat data at http://www.ruidaiwrds.info/data/link...-and-compustat

Kai Chen has a number of posts on using Stata in finance & accounting research (Calculate CFO tenure with Execucomp in Stata, Handy Stata command to create Fama-French industry classifications based on SIC codes, etc). The relevant post on linking CRSP and Compustat is here

Luis Palacios excellent tutorial (as a PDF) is here

Ian Gow has some good insight on the Compustat-CRSP linktables here

And when all else fails, you can read the manual

And if you want to check 20 firms, here are the GVKEY, CUSIP, PERMNO, and PERMCO for 20 firms in COMPUSTAT:

. list coname gvkey cnum cic npermno npermco linktype linkflag if year==2005 & (strpos(coname, "AP")==1 | strpos(coname, "AT")==1), noobs

  +------------------------------------------------------------------------------------------------+
  |                       coname    gvkey     cnum   cic   npermno   npermco   linktype   linkflag |
  |------------------------------------------------------------------------------------------------|
  |          APA ENTERPRISES INC    12482   001853   100     10547      8458         LU        BBB |
  |           APPLE COMPUTER INC     1690   037833   100     14593         7         LU        BBB |
  |  APPLERA CORP APPLIED BIOSYS     8488   038020   103     27713     21387         LC        BBB |
  | APPLERA CORP CELERA GENOMICS   127234   038020   202     86806     21387         LS        BBB |
  |    APPLIED DIGITAL SOLUTIONS    31193   038188   306     82248     13964         LU        BBB |
  |------------------------------------------------------------------------------------------------|
  |         APPLIED IMAGING CORP    63945   03820G   205     84186     15121         LU        BBB |
  |       APPLIED INNOVATION INC    21144   037916   103     79148     12140         LU        BBB |
  |  APPLIED MICRO CIRCUITS CORP    65904   03822W   109     85522     15854         LU        BBB |
  |    APPLIED SIGNAL TECHNOLOGY    27997   038237   103     78953     12045         LU        BBB |
  |           APPLIEDTHEORY CORP   120154   03828R   104     86816     16497         LU        BBB |
  |------------------------------------------------------------------------------------------------|
  |                   APPLIX INC    31144   038316   105     81137     13463         LU        BBB |
  |                  APTIMUS INC   124320   03833V   108     87230     17149         LU        BBB |
  |                  AT ROAD INC   140061   04648K   105     88617     39152         LC        BBB |
  |                     AT&T INC     9899   00206R   102     66093     21645         LC        BBB |
  |                    ATARI INC    61718   04651M   105     82704     14227         LU        BBB |
  |------------------------------------------------------------------------------------------------|
  |   ATHEROS COMMUNICATIONS INC   157635   04743P   108     90022     44878         LC        BBB |
  |         ATI TECHNOLOGIES INC    29322   001941   103     86418     16325         LU        BBB |
  |    ATLANTIC TELE-NETWORK INC    24708   049079   205     77090     11204         LU        BBB |
  |                   ATMEL CORP    23767   049513   104     76584     10860         LU        BBB |
  |                 ATTUNITY LTD    28383   M15332   105     78201     11867         LU        BBB |
  +------------------------------------------------------------------------------------------------+


. desc coname gvkey cnum cic npermno npermco linktype linkflag usedflag file

              storage   display    value
variable name   type    format     label      variable label
---------------------------------------------------------------------------------------------------------------------------------------------
coname          str28   %28s                  company name
gvkey           long    %12.0g                standard and poor's identifier
cnum            str6    %6s                   cusip issuer code
cic             str3    %3s                   cusip issue number and check digit
npermno         long    %12.0g                historical crsp permno link to compustat record
npermco         long    %12.0g                historical crsp permco link to compustat record
linktype        str2    %2s                   link type code
linkflag        str3    %3s                   link flag
usedflag        byte    %8.0g                 link used flag: 1=used; 0=not used
file            byte    %8.0g                 file identification code

[Tahseen Hasan]

Thank you David, I really appreciate your kind reply. Only thing is, I don't know how to access the CCM database. Is it hosted in WRDS or some other site? What is the web address of this table?

[David Benson]

Yes , it's in WRDS (although many institutions that subscribe to WRDS don't subscribe to the CRSP/Compustat Merged Database.) You can see them at Home > Get Data > CRSP > Annual Update > CRSP/Compustat Merged

Links to the various tables (gated, obviously)

• Fundamentals Quarterly - LINK
• Fundamentals Annual - LINK
• Linking Table - LINK

A couple of screenshots:

[Tahseen Hasan]

Thank you so much David. I am extremely grateful to you for your help with this. I really appreciate the advice and guidance