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{{Project
|Has project output=Content
|Has sponsor=McNair Center
|Has title=LBO Data Description
|Has owner=James Chen,Brian Ayash,Ed Egan
|Has project status=Complete
}}
 
 
This page is included in the project [[Leveraged Buyout Innovation (Academic Paper)]]
==Work Scripts==
===SQL===
*<code>E:\McNair\Projects\LBO\LBO academic paper patent data script pre compustat</code>
*<code>E:\McNair\Projects\LBO\LBO academic paper script post compustat</code>
===Stata===
==Work Description==
===LBO Data and Patent Data===
See script for exact work.: <code>E:\McNair\Projects\LBO\patent data script</code>
*Get the source file for the LBOs
use lbofinal to create lboreallyfinal. lboreallyfinal is the same as lbofinal but with null space in number of patents replaced with 0
FINAL DATA IN THE FOLLOWING FOLDER
<code>E:\McNair\Projects\LBO</code>
#After getting lboreallyfinal, create a table with all of its columns in addition to the lbo deal numbers, and whether it was public to private or private to private in the following steps
#import LBOcleaneddata.txt into table dealnumbxcleannames. it will have the deal numbers and cleaned original lbo names (duplicates not removed)
===Introduction of Compustat and Preparation for Stata===
See script for exact work.: <code>E:\McNair\Projects\LBO\LBO academic paper script post compustat</code>
*Create table sdc with SDC data imported from the initial LBO data.tables as follows:
*Create table LBOCOMPUSTAT4 '''SDC''' with Compustat SDC data importedfrom the initial LBO data.
*Create table dealnumbxgvkey selecting deal numbers and gvkeys from table sdc'''LBOCOMPUSTAT4''' with Compustat data imported.
*Create '''dealnumbxgvkey''' selecting deal numbers and gvkeys from table compustatnamematch with compustat names matched against themselves importedsdc.
*Create table stdcompnamestdorgnamematched '''compustatnamematch''' with standardized compustat names matched against stdorgnamethemselves imported
*Create table matchedlbocompnames '''stdcompnamestdorgnamematched''' with standardized original lbo compustat names matched to standardized compustat namesagainst stdorgname
*Create table compnamematchlbocompnames '''matchedlbocompnames''' with standardized compustat original lbo names, compustatnames, and matched to standardized original lbo compustat names
*Create table stdcompnamepatentjoin '''compnamematchlbocompnames''' with variables standardized compustat names , compustatnames, and patent numbersstandardized original lbo names
*Create table compustatpatentinfo '''stdcompnamepatentjoin''' with variables standardized compustat names, and patent numbers, and grant dates
*Create table stdcompnamexgvkeycleaned '''compustatpatentinfo''' with variables standardized compustat names , patent numbers, and gvkeysgrant dates
*Create table ALLGVKey '''stdcompnamexgvkeycleaned''' with all distinct variables standardized compustat names and gvkeys from stdcompnamexgvkeycleaned
*Create table AllYears '''ALLGVKey''' with all years distinct gvkeys from 1970 to 2016stdcompnamexgvkeycleaned
*Create table KeysXYears '''AllYears''' with variables gvkey and year. Each gvkey corresponds all years from 1970 to 47 years.2016
*Create table keysxyearsxstdcompname '''KeysXYears''' with variables gvkeys, gvkey and year. Each gvkey corresponds to 47 years, and standardized compustat names.
*Create table compupatentyearsummary '''keysxyearsxstdcompname''' with variables standardized compustat names, gvkeys, years, and number of patents per yearstandardized compustat names
*Create table dealnumbxgvkeyxlboyeartemp '''compupatentyearsummary''' with variables deal numbersstandardized compustat names, gvkeys, LBO years, and exit yearsnumber of patents per year
*Create table dealnumbxgvkeyxlboyear '''dealnumbxgvkeyxlboyeartemp''' with variables deal numbers, gvkeys, lbo LBO years, and exit years, entry year 1, entry year 2, exit year 1, and exit year 2
*Create table compupatentlboyearsummary '''dealnumbxgvkeyxlboyear''' with variables standard compustat namesdeal numbers, gvkeys, lbo years, exit years, number of patents per entry year 1, entry year 2, exit year1, and lbo entries/exits in each exit year2
*Create table statastaging '''compupatentlboyearsummary''' with all variables from compupatentlboyearsummary standard compustat names, gvkeys, years, number of patents per year, and lbo entries/exits in addition to all the pulled compustat variableseach year
*Create table sicnaicsconversion '''statastaging''' with sic codes and naics codes as a conversion table for adding naics that correspond all variables from compupatentlboyearsummary in addition to all the sic codes in blank rowspulled compustat variables
*Create '''sicnaicsconversion''' with sic codes and naics codes as a conversion table for adding naics that correspond to the sic codes in blank rows. Table from https://www.census.gov/eos/www/naics/concordances/concordances.html *'''statastagingnew ''' with two extra columns, concordsic and concordnaics, then export to stata
===Stata Work===
See script for exact work.: <code>E:\McNair\Projects\LBO\STATAdatasetup2</code> 
====Setup====
*Label Compustat/patent variables imported from SQL
*Find first fiscal year in which data appears for each company
*Find last fiscal year in which data appears for each company, or set it to 2016
*Recode the industry (based on NAICS2) to Manufacturing, Retail, Prof. Services, and other
*Generate additional lagged variables
====Analysis====
See script for exact work: <code>E:\McNair\Projects\LBO\STATAanalysis2</code>
*Summary of variables intended for use in hazard model (mean, count)
*Run Cox Proportional Hazard Model multiple times to determine statistically significant variables
RE -- Retained Earnings
==ResourcesSQL Fixes==WRDS USER(Moved here from deleted page: mcnairLBO Fix List) *Improve SIC to NAICS fill in further**Manually add in conversions from three digit SIC (e.g., 1110) to three digit NAICS (e.g., 134)**Re-import into STATAWRDS PASS: 9Mil2015
http[[category://www.axial.net/forum/how-private-equity-screens-lbo-candidates/ - Variables that private equity firms examine to decide whether or not to lboInternal]]

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