Dear members,


These days I am working on my (master) thesis and I am working with Stata in order to process the data for my thesis. I have not yet used it before so I am learning while doing. I learned a lot but now I am stuck. I am writing about convertible bonds. I have one dataset which contains (amongst other things) different dates of issuing. For example 29-01-2004 a bond issue of Company A. Another bond issue on the 20th of July of Company A and different dates for Company B. Then, I have another dataset which contains monthly dates of the amount of shares sold short. This is monthly data so usually on the 15th of every month. I am interested in the amount of shares short(var: nshort~t )during, before and after the period of the issue. Now I need to compare different information from database2(every month data) with database 1. I can’t merge these two files apparently. I tried merge pairwise but I will get a strange datafile. Is there someone who could help me? I have converted all the variables already into strings.

IssuerP is the identification number.
New_offering date is time, days from the year 1960 I believe.
Database 1 output(1/10)

| issuer~p new_of~d new_sha~g cusip_name indust~p in_ban~y sic_code |
|-----------------------------------------------------------------------------------------------|
1. | 000361 16099 32046000 AAR CORP 1 N 3720 |
2. | 000361 16272 37720000 AAR CORP 1 N 3720 |
3. | 000361 16827 36349000 AAR CORP 1 N 3720 |
4. | 000361 16922 39940227 AAR CORP 1 N 3720 |
5. | 000361 17567 37917936 AAR CORP 1 N 3720 |
|-----------------------------------------------------------------------------------------------|
6. | 000361 17567 40283131 AAR CORP 1 N 3720 |
7. | 000361 19071 40167070 AAR CORP 1 N 3720 |
8. | 000361 19071 40167070 AAR CORP 1 N 3720 |
9. | 000361 19403 39694849 AAR CORP 1 N 3720 |
10. | 000886 15855 801000000 ADC TELECOMMUNICATIONS INC 1 N 3661 |
+-----------------------------------------------------------------------------------------------+



Database 2
+-----------------------------------------------------------------+
| nshort~t nsplit~e tic cusip sic issuer~p ntime |
|-----------------------------------------------------------------|
1. | 518299 14640 AIR 000361105 5080 000361 14623 |
2. | 438542 14669 AIR 000361105 5080 000361 14655 |
3. | 438412 14700 AIR 000361105 5080 000361 14684 |
4. | 386472 14730 AIR 000361105 5080 000361 14714 |
5. | 363889 14761 AIR 000361105 5080 000361 14745 |
|-----------------------------------------------------------------|
6. | 452221 14791 AIR 000361105 5080 000361 14776 |
7. | 492179 14822 AIR 000361105 5080 000361 14805 |
8. | 506868 14853 AIR 000361105 5080 000361 14837 |
9. | 436580 14883 AIR 000361105 5080 000361 14868 |
10. | 660439 14914 AIR 000361105 5080 000361 14896 |

I have come to a datafile which I can probably work with but I am not sure how because the first date relates to the issue of the convertible and the second date to the short interest. The short interests dates are given every month. Usually around middle of the month.





issuer~p offerin~e shares~g time shortint shorti~j datadate splitad~e time2 differ~e

1. 000361 14feb2013 39694849 19403 518299 518299 14jan2000 31jan2000 14623 -4780
2. 000361 14feb2013 39694849 19403 438542 438542 15feb2000 29feb2000 14655 -4748
3. 000361 14feb2013 39694849 19403 438412 438412 15mar2000 31mar2000 14684 -4719
4. 000361 14feb2013 39694849 19403 386472 386472 14apr2000 30apr2000 14714 -4689
5. 000361 14feb2013 39694849 19403 363889 363889 15may2000 31may2000 14745 -4658

6. 000361 14feb2013 39694849 19403 452221 452221 15jun2000 30jun2000 14776 -4627
7. 000361 14feb2013 39694849 19403 492179 492179 14jul2000 31jul2000 14805 -4598
8. 000361 14feb2013 39694849 19403 506868 506868 15aug2000 31aug2000 14837 -4566
9. 000361 14feb2013 39694849 19403 436580 436580 15sep2000 30sep2000 14868 -4535
10. 000361 14feb2013 39694849 19403 660439 660439 13oct2000 31oct2000 14896 -4507

11. 000361 14feb2013 39694849 19403 604438 604438 15nov2000 30nov2000 14929 -4474
12. 000361 19mar2012 40167070 19071 518299 518299 14jan2000 31jan2000 14623 -4448
13. 000361 19mar2012 40167070 19071 518299 518299 14jan2000 31jan2000 14623 -4448
14. 000361 14feb2013 39694849 19403 499438 499438 15dec2000 31dec2000 14959 -4444
15. 000361 19mar2012 40167070 19071 438542 438542 15feb2000 29feb2000 14655 -4416

So for example I have an issue(database1) of Company x on the first of januari 2003. Then i want to know the difference in the amount of shares sold short(database 2) between december 2002 and januari 2003 for that company. So i want to know the influence of the (announced) issue). I find it hard to explain my question but I am hoping for some feedback.


Kind regards,

Sierk