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# Re: st: bootstrap weighted mean

 From Shuaizhang Feng <[email protected]> To [email protected] Subject Re: st: bootstrap weighted mean Date Thu, 3 Oct 2013 09:25:41 +0800

```Dear all: thanks a lot for all the replies. It turned out that - set
trace on was tremendously helpful. After I drop ",detail" the code
works fine. many thanks for other suggestions too.    SZ

On Wed, Oct 2, 2013 at 7:49 PM, Stas Kolenikov <[email protected]> wrote:
> So why exactly do you want to do this? This is Stata's -ratio-
> command, and what you are doing is achievable with -bootstrap :
> ratio-. If you need to incorporate weights, you can use -bsweights- /
> -bs4rw- combo (the first is mine, the second is Jeff Pitblado's).
>
> -- Stas Kolenikov, PhD, PStat (ASA, SSC)
> -- Senior Survey Statistician, Abt SRBI
> -- Opinions stated in this email are mine only, and do not reflect the
> position of my employer
> -- http://stas.kolenikov.name
>
>
>
> On Tue, Oct 1, 2013 at 9:40 PM, Shuaizhang Feng
> <[email protected]> wrote:
>> Dear list:
>>
>> I was trying to bootstrap standard errors for the mean of two
>> variables. When I do so for simple means, i use the following ado
>> file.
>>
>> program myratio, rclass
>>          summarize `1'
>>           local a1 = r(mean)
>>           summarize `2'
>>           local a2 = r(mean)
>>  return scalar ratio = `a1'/`a2'
>> end
>>
>> and then do the following:
>>
>> .bootstrap r(ratio), reps(100) saving(cratio, replace): myratio u1 u2, detail
>>
>> and this gives the results as expected.
>>
>> however, when i wanted to do ratio of weighted means, i modified the
>> ado file as follows:
>>
>> program myratio_w, rclass
>>       summarize `1'[iw=`3']
>>           local a1 = r(mean)
>>       summarize `2'[iw=`3']
>>           local a2 = r(mean)
>>  return scalar ratio = `a1'/`a2'
>> end
>>
>>
>> and then use:
>>
>> bootstrap r(ratio), reps(100) saving(cratio, replace): myratio_w u1 u2
>> weight, detail
>>
>> then stata does not work properly and gives me the following message:
>>
>> invalid syntax
>> an error occurred when bootstrap executed myratio_w
>> r(198);
>>
>>
>> I am wondering if anyone from the list can help me out. the difference
>> between the two ado files seem small Thanks in advance.
>>
>> SZ
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```