Compustat Segment files, count industrial segments per firm-year

comp_segment_industrial_segment_count.sas

/* count industrial segments
  starting dataset, work.a_start with variables gvkey, fyear, datadate from Funda
  */

data b_segm (keep = GVKEY datadate STYPE SID IAS CAPXS NAICS NAICSH NAICSS1 NAICSS2 NIS OPS SALES SICS1 SICS2 SNMS SOPTP1 INTSEG);
set segments.Wrds_segmerged;
/* prevent duplicates: use the data when first published (not later years)*/
if srcdate eq datadate;
/* select business/operating (or, industrial) segments */
if stype IN ("BUSSEG", "OPSEG");
/* keep segments that have SIC industry code */
if SICS1 ne "";
/* keep segments with positive sales */
if sales > 0;
run;

proc sql;
  create table work.c_joined as
  select a.*, b.SICS1 as sics
  from work.a_start a, work.b_segm
  where a.gvkey = b.gvkey and a.datadate = b.datadate;
quit;

/* drop segments with same industry (since we want a count on unique industry codes) */
proc sort data=c_joined nodupkey; by gvkey fyear sics;run;

/* count */
proc sql;
  create table work.d_count as
  select distinct gvkey, fyear, count(*) as numSegs from work.c_joined
  group by gvkey, fyear;
quit;