Hello, I have two questions regarding the data set below. First I have two data sets, one that shows dates of crimes committed before a treatment effect and crimes after the treatment effect. I needed to combine these two data sets together. Their common variables was person_id. The problem I run into is the way the variable person_ID was coded.For example there is a person in this data set that was arrested at three distinct dates, he is given the ID 1, so this person appears as 1 three times in the data set. In the second dataset this individual was arrested twice so in the merged data set 1 should appear 5 times. When I try the command merge is fails to merge in any of the possible combinations. I don't know how to combine the data sets such that each of the 5 observations are recorded. I tried joining these two data sets using the joinby command but got tons of duplicates as can be seen by this sample code.

The second question I have is that I need to create a dummy variable that takes the value 1 if the persons arrest date was later than their disposition date. I'm not sure how to do this

* Example generated by -dataex-. To install: ssc install dataex
clear
input int person_id str10 pastarrests_date long caseid str10(arrest_date dispos_date) byte treat
1 "2008-06-14" 88413 "2013-04-04" "2013-06-22" 0
1 "2008-06-14" 39970 "2012-07-11" "2012-10-20" 1
1 "2008-06-14" 57514 "2012-01-04" "2012-03-27" 0
1 "2010-04-09" 39970 "2012-07-11" "2012-10-20" 1
1 "2010-04-09" 57514 "2012-01-04" "2012-03-27" 0
1 "2010-04-09" 88413 "2013-04-04" "2013-06-22" 0
5 "2009-06-07" 40216 "2012-03-31" "2013-03-25" 0
5 "2010-05-20" 40216 "2012-03-31" "2013-03-25" 0
6 "2008-03-16" 92255 "2012-12-09" "2013-11-09" 0
6 "2009-01-20" 92255 "2012-12-09" "2013-11-09" 0
6 "2009-09-18" 92255 "2012-12-09" "2013-11-09" 0
8 "2009-08-05" 2913 "2012-10-06" "2013-12-29" 1
8 "2009-08-05" 6304 "2013-04-06" "2013-07-07" 0
8 "2010-06-18" 6304 "2013-04-06" "2013-07-07" 0
8 "2010-06-18" 2913 "2012-10-06" "2013-12-29" 1
8 "2011-05-06" 6304 "2013-04-06" "2013-07-07" 0
8 "2011-05-06" 2913 "2012-10-06" "2013-12-29" 1
8 "2011-06-17" 2913 "2012-10-06" "2013-12-29" 1
8 "2011-06-17" 6304 "2013-04-06" "2013-07-07" 0
9 "2011-02-06" 31881 "2013-09-25" "2013-12-29" 1
9 "2011-02-06" 82277 "2012-01-12" "2012-11-08" 0
10 "2009-06-03" 11354 "2013-07-03" "2014-12-13" 1
10 "2009-08-15" 11354 "2013-07-03" "2014-12-13" 1
10 "2010-10-29" 11354 "2013-07-03" "2014-12-13" 1
11 "2008-12-16" 49941 "2013-03-17" "2013-05-11" 1
11 "2011-01-31" 49941 "2013-03-17" "2013-05-11" 1
11 "2011-05-09" 49941 "2013-03-17" "2013-05-11" 1
12 "2009-06-03" 59616 "2013-06-25" "2013-08-23" 0
13 "2008-05-16" 40377 "2012-11-04" "2013-03-05" 1
13 "2008-05-16" 88153 "2012-10-29" "2013-01-21" 1
13 "2008-05-16" 39447 "2013-07-31" "2013-08-16" 1
13 "2008-09-05" 88153 "2012-10-29" "2013-01-21" 1
13 "2008-09-05" 39447 "2013-07-31" "2013-08-16" 1
13 "2008-09-05" 40377 "2012-11-04" "2013-03-05" 1
13 "2009-09-09" 39447 "2013-07-31" "2013-08-16" 1
13 "2009-09-09" 88153 "2012-10-29" "2013-01-21" 1
13 "2009-09-09" 40377 "2012-11-04" "2013-03-05" 1
13 "2010-02-21" 40377 "2012-11-04" "2013-03-05" 1
13 "2010-02-21" 39447 "2013-07-31" "2013-08-16" 1
13 "2010-02-21" 88153 "2012-10-29" "2013-01-21" 1
13 "2010-12-28" 88153 "2012-10-29" "2013-01-21" 1
13 "2010-12-28" 40377 "2012-11-04" "2013-03-05" 1
13 "2010-12-28" 39447 "2013-07-31" "2013-08-16" 1
13 "2011-04-16" 88153 "2012-10-29" "2013-01-21" 1
13 "2011-04-16" 40377 "2012-11-04" "2013-03-05" 1
13 "2011-04-16" 39447 "2013-07-31" "2013-08-16" 1
13 "2011-08-07" 39447 "2013-07-31" "2013-08-16" 1
13 "2011-08-07" 88153 "2012-10-29" "2013-01-21" 1
13 "2011-08-07" 40377 "2012-11-04" "2013-03-05" 1
13 "2011-10-26" 39447 "2013-07-31" "2013-08-16" 1
13 "2011-10-26" 40377 "2012-11-04" "2013-03-05" 1
13 "2011-10-26" 88153 "2012-10-29" "2013-01-21" 1
14 "2010-01-01" 56468 "2013-04-05" "2013-10-09" 1
14 "2010-09-28" 56468 "2013-04-05" "2013-10-09" 1
15 "2008-01-22" 96126 "2012-06-13" "2012-08-15" 0
15 "2008-01-22" 19842 "2012-03-31" "2013-09-08" 1
15 "2008-11-30" 19842 "2012-03-31" "2013-09-08" 1
15 "2008-11-30" 96126 "2012-06-13" "2012-08-15" 0
15 "2008-12-31" 19842 "2012-03-31" "2013-09-08" 1
15 "2008-12-31" 96126 "2012-06-13" "2012-08-15" 0
15 "2009-02-06" 19842 "2012-03-31" "2013-09-08" 1
15 "2009-02-06" 96126 "2012-06-13" "2012-08-15" 0
15 "2010-12-01" 96126 "2012-06-13" "2012-08-15" 0
15 "2010-12-01" 19842 "2012-03-31" "2013-09-08" 1
16 "2008-01-25" 95551 "2012-05-23" "2012-08-02" 1
16 "2008-05-30" 95551 "2012-05-23" "2012-08-02" 1
16 "2008-08-23" 95551 "2012-05-23" "2012-08-02" 1
16 "2009-12-11" 95551 "2012-05-23" "2012-08-02" 1
17 "2009-06-01" 97880 "2012-05-22" "2012-06-15" 1
17 "2011-03-17" 97880 "2012-05-22" "2012-06-15" 1
17 "2011-09-30" 97880 "2012-05-22" "2012-06-15" 1
18 "2008-10-06" 26780 "2012-04-05" "2013-01-26" 1
18 "2008-10-06" 37756 "2012-01-10" "2013-06-03" 1
18 "2008-10-06" 57949 "2012-04-18" "2012-05-27" 0
18 "2008-12-25" 26780 "2012-04-05" "2013-01-26" 1
18 "2008-12-25" 37756 "2012-01-10" "2013-06-03" 1
18 "2008-12-25" 57949 "2012-04-18" "2012-05-27" 0
18 "2009-08-07" 37756 "2012-01-10" "2013-06-03" 1
18 "2009-08-07" 26780 "2012-04-05" "2013-01-26" 1
18 "2009-08-07" 57949 "2012-04-18" "2012-05-27" 0
18 "2009-11-02" 37756 "2012-01-10" "2013-06-03" 1
18 "2009-11-02" 26780 "2012-04-05" "2013-01-26" 1
18 "2009-11-02" 57949 "2012-04-18" "2012-05-27" 0
18 "2009-11-13" 26780 "2012-04-05" "2013-01-26" 1
18 "2009-11-13" 37756 "2012-01-10" "2013-06-03" 1
18 "2009-11-13" 57949 "2012-04-18" "2012-05-27" 0
18 "2009-11-22" 57949 "2012-04-18" "2012-05-27" 0
18 "2009-11-22" 26780 "2012-04-05" "2013-01-26" 1
18 "2009-11-22" 37756 "2012-01-10" "2013-06-03" 1
18 "2010-01-08" 57949 "2012-04-18" "2012-05-27" 0
18 "2010-01-08" 37756 "2012-01-10" "2013-06-03" 1
18 "2010-01-08" 26780 "2012-04-05" "2013-01-26" 1
18 "2010-05-02" 37756 "2012-01-10" "2013-06-03" 1
18 "2010-05-02" 26780 "2012-04-05" "2013-01-26" 1
18 "2010-05-02" 57949 "2012-04-18" "2012-05-27" 0
19 "2008-02-16" 39548 "2013-09-20" "2014-08-29" 0
19 "2008-02-16" 62439 "2013-07-08" "2013-09-16" 1
24 "2008-06-16" 5690 "2012-12-25" "2013-01-07" 1
24 "2009-08-02" 5690 "2012-12-25" "2013-01-07" 1
24 "2009-11-16" 5690 "2012-12-25" "2013-01-07" 1
end
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