CRSP_CCM_LINKUSED - CRSP-Centric Link Used History
|PERMNO*||integer, primary key (1)||CRSP PERMNO used as basis for this history|
|ULINKID||integer||Unique ID per link associated with PERMNO. This is used to join with range data in the LINKRANGE table that describes the data ranges applied from used GVKEYs.|
|ULINKDT||integer (date), primary key (2)||First effective calendar date of link record range|
|ULINKENDDT||integer (date)||Last effective calendar date of link record range|
|UPERMNO||integer||Linked CRSP PERMNO, 0 if no CRSP security link exists|
|UPERMCO||integer||Linked CRSP PERMCO, 0 if no CRSP company link exists|
Primary issue marker for the link. Based on Compustat Primary/Joiner flag (PRIMISS), indicating whether this link is to Compustat’s marked primary security during this range.
Link type code. Each link is given a code describing the connection between the CRSP and Compustat data. Values are:
1 = this link is applicable to the selected PERMNO and used to identify ranges of Compustat data from a GVKEY used to build a composite GVKEY record corresponding to the PERMNO.
-1 = this link is informational, indirectly related to the PERMNO, but not used.
* - The PERMNO is the CRSP security identifier used as the basis for a composite Compustat record and serves as the primary identifier for the composite record. In CRSPAccess programming this field is not present in the structure but inherited from the master structure for the company. The APERMNO or PPERMNO key types store the PERMNO in the CCM structure CCMID field and marks the CCMIDTYPE as 3. In standalone usage the PERMNO field is included.