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From | Ignacio Martinez <ignacio@virginia.edu> |
To | statalist@hsphsun2.harvard.edu |
Subject | Re: AW: AW: st: AW: Generating a dropout dummy variable? |
Date | Sun, 27 Jun 2010 17:12:31 -0400 |
Now I think I finally know what I need to do. First I need to generate an indicator ==1 if is the last time i see the individual (for example for id=1 if the last time i see him is t=2002 then the indicator ==1 in 2002 and ==0 in the other periods) Then i need to create the dropout indicator following the rule that if last year ==1 and graduated!=1 then dropout==1 I think this is going to work, but I'm not sure how to code it. Thanks for the help!!! -Ignacio On Sun, 2010-06-27 at 20:22 +0200, Martin Weiss wrote: > <> > > > "So the code should do something like: when is the first time I see the > student. Do I see him after the first time. Was he graduated the last > time i saw him." > > > > The answers to these questions are quite easily obtained, actually: > > > ************* > //Create data > clear* > set obs 1000 > set seed 43550 > > //id > gen int id=_n > //random start year > gen startyear=1999+irecode(runiform(),0,.2,.5,.7,1) > > //expand to # of time periods > expand 7 > > bys id: gen int year=_n-1+startyear > gen byte graduated= /* > */ runiform()<0.3 > > drop if runiform()<.3 > > //throw out twice graduated guys > bys id: egen mytotal=total(graduated) > drop if mytotal>2 & !mi(mytotal) > drop mytotal startyear > drop if year==2009 > > xtset id year > > > > //So the code should do something like: > //when is the first time I see the student? > bys id: egen firstyear=min(year) > > //Do I see him after the first time? > by id: gen byte afterfirsttime=year>firstyear & /* > */ !mi(year) > > //Was he graduated the last time I saw him? > bys id (year): gen byte gradlasttime=(_n==_N)*graduated > > l in 1/21, sepby(id) noo ab(20) > ************* > > > > HTH > Martin > > > -----Ursprüngliche Nachricht----- > Von: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] Im Auftrag von Ignacio Martinez > Gesendet: Sonntag, 27. Juni 2010 19:54 > An: statalist@hsphsun2.harvard.edu > Betreff: Re: AW: st: AW: Generating a dropout dummy variable? > > Thanks > Now i understand better. > > I think I explain my self wrong the first time so the code is not doing > exactly what I need. > > My data goes from 2000 to 2008. So is possible that a student enroll in > any year between 2000 and 2008. If I'm understanding the code right I > should change the first line to: > bys id: egen myvar=total(inlist(year,2000,2008)) > > Is this right? > > But now I'm not sure how should I change the second line. > > The problem is that some student were enroll for the first time in 2000 > some others in 2001, 2002, etc. > > So the code should do something like: when is the first time I see the > student. Do I see him after the first time. Was he graduated the last > time i saw him. Or something like that > > Thanks a lot for your help. > > -Ignacio > > > On Sun, 2010-06-27 at 19:38 +0200, Martin Weiss wrote: > > <> > > > > " About your code... I'm kind of lost on how you create the dropout > > indicator. Could you explain a little that piece of code?" > > > > > > > > > > > > ************* > > //get "dropout" indicator > > > > //Do I see "id" in 2000 and 2001? > > bys id: egen myvar=total(inlist(year,2000,2001)) > > > > //How many times did I see "id" between 2002 and 2006? > > bys id: egen myvar2=total(inrange(year,2002,2006)) > > > > //dropout is 1 if I saw "id" in 2000 and 2001 > > //and did not see him again afterwards > > //and, in 2001, his "graduated" was not 1 > > bys id: gen dropout=((myvar==2)*(myvar2==0))& /* > > */ ((graduated!=1)*(year==2001)) > > ************* > > > > > > See this thread for the tricks re "conditions": http://www.stata.com/statalist/archive/2010-06/msg00985.html > > > > > > > > HTH > > Martin > > > > > > -----Ursprüngliche Nachricht----- > > Von: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] Im Auftrag von Ignacio Martinez > > Gesendet: Sonntag, 27. Juni 2010 19:33 > > An: statalist@hsphsun2.harvard.edu > > Betreff: Re: st: AW: Generating a dropout dummy variable? > > > > About the second part: > > What I was trying to say is that if i see a student in the year 2000 and > > i don't see him in 2001 because he is taking a break but in the year > > 2005 he is back in my sample I don't want to mark him as drop out but I > > want to generate a variable that says that he took a 4 year break. > > > > About your code... I'm kind of lost on how you create the dropout > > indicator. Could you explain a little that piece of code? > > > > Thanks a lot > > > > -Ignacio > > > > > > On Sun, 2010-06-27 at 19:01 +0200, Martin Weiss wrote: > > > <> > > > > > > The first part could be: > > > > > > > > > ************* > > > > > > //Create data > > > clear* > > > set obs 1000 > > > set seed 43550 > > > > > > //id > > > gen int id=_n > > > > > > //expand to # of time periods > > > expand 7 > > > > > > bys id: gen int year=_n+1999 > > > gen byte graduated= /* > > > */ cond(runiform()<0.3 & year==2001,1,0) > > > > > > drop if runiform()<.7 > > > > > > xtset id year > > > > > > //get "dropout" indicator > > > bys id: egen myvar=total(inlist(year,2000,2001)) > > > bys id: egen myvar2=total(inrange(year,2002,2006)) > > > bys id: gen dropout=((myvar==2)*(myvar2==0))& /* > > > */ ((graduated!=1)*(year==2001)) > > > drop myvar* > > > > > > //take a look > > > bys id: egen anydropout=max(dropout) > > > l if anydropout, sepby(id) > > > ************* > > > > > > > > > I do not understand the second part. Why would dropout be 1 in 2000 if you saw the guy in 2000? > > > > > > > > > HTH > > > Martin > > > > > > -----Ursprüngliche Nachricht----- > > > Von: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] Im Auftrag von Ignacio Martinez > > > Gesendet: Sonntag, 27. Juni 2010 15:54 > > > An: statalist@hsphsun2.harvard.edu > > > Betreff: st: Generating a dropout dummy variable? > > > > > > Hi, > > > > > > > > > My panel has the following variables: Year (from 2000 to 2008), ID, > > > Graduated (an indicator =1 if the student graduated that year) . > > > > > > I want to generate a dropout variable. If I see ID==1111 in year==2000 > > > and 2001 but not after that and graduated !=1 in 2001 I want dropout==1 > > > in 2001 . The only other detail is that if a see someone in 2000 and > > > then I see him again in 2006 with graduated=1 I don't want dropout =1 in > > > 2000 I want other variable that is break=5 (that student took 5 year of > > > break) > > > > > > > > > Thanks for the help > > > > > > > > > -Ignacio > > > > > > > > > * > > > * For searches and help try: > > > * http://www.stata.com/help.cgi?search > > > * http://www.stata.com/support/statalist/faq > > > * http://www.ats.ucla.edu/stat/stata/ > > > > > > > > > * > > > * For searches and help try: > > > * http://www.stata.com/help.cgi?search > > > * http://www.stata.com/support/statalist/faq > > > * http://www.ats.ucla.edu/stat/stata/ > > > > > > * > > * For searches and help try: > > * http://www.stata.com/help.cgi?search > > * http://www.stata.com/support/statalist/faq > > * http://www.ats.ucla.edu/stat/stata/ > > > > > > * > > * For searches and help try: > > * http://www.stata.com/help.cgi?search > > * http://www.stata.com/support/statalist/faq > > * http://www.ats.ucla.edu/stat/stata/ > > > * > * For searches and help try: > * http://www.stata.com/help.cgi?search > * http://www.stata.com/support/statalist/faq > * http://www.ats.ucla.edu/stat/stata/ > > > * > * For searches and help try: > * http://www.stata.com/help.cgi?search > * http://www.stata.com/support/statalist/faq > * http://www.ats.ucla.edu/stat/stata/ * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/