Merging Compustat/CRSP -> which firm to take when a merger took place?
Posted: 31 January 2016 07:40 PM   [ Ignore ]
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Hi,

I’m constructing spreadsheets that contain HPR for every S&P 500 constituent. Starting at 19640331 - the first date for which Compustat lists the S&P 500 constituent list.

Since Compustat does only provide security data from 1983, I use CRSP to get HPR data from 19640331 - 19830331.

For the first year, starting at 19640331, when I match on CUSIPS I get the HPR for 314 out of 500 firms. I want to match the remaining firms by hand.

For most firms it is no problem: I look up the company history on Wikipedia, and find the names of predecessors of the company in the wiki, which I can then find based on their historical names in CRSP. For example BAKER HUGHES INC (permco 20253); its predecessors are BAKER INTERNATIONAL CORP (permco 23520) and BAKER OIL TOOLS INC (permco 23520). So the matching by hand is working fine here.

But there are firms that exist as the result of a merger. When both predecessors of the merged firm are listed, I do not know which one to use. For example NORFOLK SOUTHERN CORP (permco 21294). This company is the result of a merger between NORFOLK & WESTERN RAILWAY CO (permco 22446) and SOUTHERN RAILWAY CO (permco 22530). How do I know which of the two was in the S&P 500 per 1964?

Thanks a lot!! in advance

JC Boer

 

 

 

 

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Posted: 31 January 2016 08:38 PM   [ Ignore ]   [ # 1 ]
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hi,

I’ve forwarded your question to the Google group, and will post any replies here.

Best Regards,

Joost

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To reply/post new questions: Please use the group WRDS/SAS on Google Groups! http://groups.google.com/d/forum/wrdssas

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Posted: 01 February 2016 04:05 AM   [ Ignore ]   [ # 2 ]
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Hi Joost,

Thanks for your help.

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