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From |
Nikhil Srivastava <nikhil.del85@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: Randomly picking observations based on a certain condition |

Date |
Fri, 15 Apr 2011 15:52:32 -0700 |

This works!Thanks a lot for the help. Nikhil On Wed, Apr 13, 2011 at 3:16 PM, Andrew Dyck <tempmail@andrewdyck.com> wrote: > After you consider the comments from Nick and J, you wish to proceed > with your analysis as you initially stated it, I think the following > should work. Here I create some sample data with 50 observations and 5 > groups (quintiles). See if this might work for your data the way I > understood your question. I use the cutoff of 10 adults instead of 100 > to keep the dataset small. > > * sample data > set obs 50 > egen group = seq(), from(1) to(5) > gen adults = round( runiform()*5, 2 ) > > * random variable for sorting > gen r = runiform() > > * create a cumulative sum of adults > * sorting randomly within the group. > bysort group (r): gen cumul_adults = adults[1] > bysort group : replace cumul_adults = adults[_n] + cumul_adults[_n-1] if _n > 1 > drop r > > * keep all obs below the cutoff > keep if cumul_adults <= 10 > > Good luck, > Andrew > > > On Wed, Apr 13, 2011 at 2:02 PM, Nikhil Srivastava > <nikhil.del85@gmail.com> wrote: >> >> I am not trying to actually sample households. As I wrote in my rely >> to Nick,I am trying look at the effectiveness of a transfer program >> targeted to adults of a household which has a certain exclusion error. >> The exclusion error that we are assuming is that 1 percent of eligible >> participants within each expenditure quintile do not receive the >> benefits. In my sample within the first quintile 1 percent of the >> total adults comes to around 100. Thus for the first quintile I need >> to randomly assign non-beneficiary status to households so that the >> total number of adults for these households comes to 100. Similarly I >> have to pick randomly 1 percent of adults for each quintile and assign >> them non-beneficiary status. In my previous mail I used the number 100 >> as an example. Thanks >> >> Nikhil >> >> On Wed, Apr 13, 2011 at 1:06 PM, Joerg Luedicke >> <joerg.luedicke@gmail.com> wrote: >> > On Wed, Apr 13, 2011 at 3:17 PM, Nikhil Srivastava >> > <nikhil.del85@gmail.com> wrote: >> >> Hi, >> >> >> >> I have a dataset at the household level which contains the expenditure >> >> details of a sample of households. The dataset also records the number >> >> of adults within each household. I have divided this dataset into 5 >> >> quintiles based on the level of expenditure. Now I need to randomly >> >> select a set of observations within each quintile so that the sum of >> >> the adults for those observations comes to 100. Could somebody please >> >> help me in writing a code for this part? >> >> >> >> I would really appreciate any help in this regard. Thanks >> > >> > Do I understand that right, you want to sample households, and within >> > each quintile of household expenditure, the number of household >> > members among sampled households is supposed to add up to 100? Why >> > would you do that? Why not just taking a random sample of households >> > or a stratified sample with respect to household size, if that is a >> > concern. That way, you would at least have a clear picture of the >> > population you are targeting, whereas in the other case, this picture >> > becomes pretty blurry, no? >> > >> > J. >> > * >> > * 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/

**References**:**st: Randomly picking observations based on a certain condition***From:*Nikhil Srivastava <nikhil.del85@gmail.com>

**Re: st: Randomly picking observations based on a certain condition***From:*Joerg Luedicke <joerg.luedicke@gmail.com>

**Re: st: Randomly picking observations based on a certain condition***From:*Nikhil Srivastava <nikhil.del85@gmail.com>

**Re: st: Randomly picking observations based on a certain condition***From:*Andrew Dyck <tempmail@andrewdyck.com>

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