CRSP-Centric Link Usage

Accessing Compustat data through ts_print and TsQuery is done through the CRSP-centric mode, meaning that the primary access key in this mode is CRSP PERMNO rather than GVKEY, as used in the Native Access mode. The CRSP identifiers are the access keys while the Compustat identifiers become attributes. There are two options: Primary only, which mirrors the company-level link by ignoring links not to the primary security, and All, which allows use of any link to the PERMNO.

In CRSP-Centric mode a composite record is built using the CRSP Link reading one or more GVKEYs. All GVKEYS with some presence of the PERMNO in the link are accessed. A used-link history is built from these link records by identifying those that cover the ranges of Compustat data needed to link to the CRSP identifier. For time series items that are stored on a fiscal period basis, the link ranges are translated to a fiscal range. This translation simplifies the selection of fundamental data that are applicable to the range and allows for the creation of a composite Compustat record from the applicable ranges that correspond to a CRSP security.

Records in CRSP-Centric form are identical in layout to the native records, but use CRSP PERMNO as the effective key. The Compustat component identifiers – GVKEY, IID, and PRIMISS are available in a Link Used table in the CRSP records.

Using the CRSP-Centric view simplifies access when viewing Compustat data through CRSP. One drawback, however, is that only data considered a direct link to CRSP, applied using CRSP link rules, are available.

The example that follows accessed data natively, then through the CRSP-centric view using PERMNO.

Example: Accessing two separate GVKEYs from the Link table, see that both share a single PERMNO.

GVKEY = 011947
Link History
LINKDT LINKENDDT LPERMNO LPERMCO LIID LINKTYPE LINKPRIM
19820701
19860304 
0
0
00X
NR
C
19860305
19890228 
10083 
8026
01
LU
P
GVKEY = 015495
Link History
LINKDT LINKENDDT LPERMNO LPERMCO LIID LINKTYPE LINKPRIM
19880101 19890227 0 0 00X NU C
19890228 19930909 10083 8026 01 LC C
19930910 19990304 0 0 01 NR C

Using CRSP-Centric access, the LINKUSED data show which GVKEYs and IIDs are used to build a composite record by PERMNO. Only the rows with USEDFLAG=1 show the GVKEYs and calendar ranges used to build the composite record for PERMNO 10083. table, access the composite history using the Primary PERMNO (LINKPRIM=P)

PERMNO = 10083
Link Used
LINKDT LINKENDDT GVKEY IID LINKID PERMNO PERMCO USEDFLAG LINKPRIM LINKTYPE
19820701 19860304 11947 00X 5 0 0 -1 C NR
19860305 19890228 11947 01 6 10083 8026 1 P LU
19880101 19890227 15495 00X 0 0 0 -1 C NU
19890228 19930909 15495 01 1 10083 8026 1 C LC
19930910 19990304 15495 01 2 0 0 -1 C NR
19990305 20051019 15495 01 3 86787 16430 -1 C LC
20051020 99999999 15495 01 4 0 0 -1 C NR