Hi
I want to test the impact of firms receiving investment on firm turnover. I have a panel data covering c50,000 firms and 10 (consecutive) years of data per firm.
Investment is a dummy variable (=1 for firms who receive the investment (treated); 0 otherwise (control)). I also have a DealYear variable which shows the year in which each firm received the investment. Post is a dummy equaling 1 where Year>= DealYear for treated firms (ie. it is 0 before they receive investment and 1 after).
I want to match on industry group (a time-static variable) and TotalAssets in the year directly before the DealYear. ie. if a firm received investment in 2006, I want to match on the industry group and TotalAssets of the treated firm and the control firm in 2005. Thus I am matching firms which, in each case, were similar in the year before the treated firm received investment.
As such, there are two elements I am currently unsure of incorporating into my approach:
1. The event date for each treated firm is different
2. I want to match on TotalAssets in the pre-event year in each case, so this will also differ for each firm
I am matching with replacement, ie. the same control can be used for more than one treated firm.
I have attached a simplified dataex data example to illustrate.
I searched through the forum to try to find a solution but I was only able to find this similar post: https://www.statalist.org/forums/for...=1591791272650 but there was no definite solution.
I hope the above is as clear and as detailed as possible.
Any advice is appreciated,
Paul
I want to test the impact of firms receiving investment on firm turnover. I have a panel data covering c50,000 firms and 10 (consecutive) years of data per firm.
Investment is a dummy variable (=1 for firms who receive the investment (treated); 0 otherwise (control)). I also have a DealYear variable which shows the year in which each firm received the investment. Post is a dummy equaling 1 where Year>= DealYear for treated firms (ie. it is 0 before they receive investment and 1 after).
I want to match on industry group (a time-static variable) and TotalAssets in the year directly before the DealYear. ie. if a firm received investment in 2006, I want to match on the industry group and TotalAssets of the treated firm and the control firm in 2005. Thus I am matching firms which, in each case, were similar in the year before the treated firm received investment.
As such, there are two elements I am currently unsure of incorporating into my approach:
1. The event date for each treated firm is different
2. I want to match on TotalAssets in the pre-event year in each case, so this will also differ for each firm
I am matching with replacement, ie. the same control can be used for more than one treated firm.
I have attached a simplified dataex data example to illustrate.
Code:
* Example generated by -dataex-. To install: ssc install dataex clear input str10 FirmName float(Year InvestmentDummy IndustryGroup Turnover TotalAssets DealYear Post) "Alpha" 2001 1 44 1019 10 2005 0 "Alpha" 2002 1 44 1918 8 2005 0 "Alpha" 2003 1 44 1111 8 2005 0 "Alpha" 2004 1 44 1123 9 2005 0 "Alpha" 2005 1 44 1234 7 2005 1 "Alpha" 2006 1 44 1555 12 2005 1 "Alpha" 2007 1 44 2333 13 2005 1 "Alpha" 2008 1 44 2112 15 2005 1 "Alpha" 2009 1 44 2121 21 2005 1 "Alpha" 2010 1 44 1222 17 2005 1 "Lok" 2001 0 12 33 14 . . "Lok" 2002 0 12 44 12 . . "Lok" 2003 0 12 59 12 . . "Lok" 2004 0 12 34 15 . . "Lok" 2005 0 12 32 19 . . "Lok" 2006 0 12 47 19 . . "Lok" 2007 0 12 45 11 . . "Lok" 2008 0 12 32 14 . . "Lok" 2009 0 12 11 9 . . "Lok" 2010 0 12 12 12 . . "Cooler Ltd" 2001 1 88 333 12 2008 0 "Cooler Ltd" 2002 1 88 332 13 2008 0 "Cooler Ltd" 2003 1 88 356 14 2008 0 "Cooler Ltd" 2004 1 88 368 17 2008 0 "Cooler Ltd" 2005 1 88 311 28 2008 0 "Cooler Ltd" 2006 1 88 395 27 2008 0 "Cooler Ltd" 2007 1 88 346 14 2008 0 "Cooler Ltd" 2008 1 88 213 14 2008 1 "Cooler Ltd" 2009 1 88 217 9 2008 1 "Cooler Ltd" 2010 1 88 298 12 2008 1 end
I searched through the forum to try to find a solution but I was only able to find this similar post: https://www.statalist.org/forums/for...=1591791272650 but there was no definite solution.
I hope the above is as clear and as detailed as possible.
Any advice is appreciated,
Paul
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