Re: st: bootstrap error: insufficient observations ...

[Guido Heineck <guido.heineck@gmx.net>]

Dear Maarten,

sorry for the late reply, but as ever thank you for your insights. I am 
however somewhat puzzled that the code I provided first used to work in 
Stata 9 (earlier this year), but not anymore in Stata 10.

Thanks again,
Guido


> ------------------------------
>
> Date: Mon, 1 Oct 2007 10:44:50 +0100 (BST)
> From: Maarten buis <maartenbuis@yahoo.co.uk>
> Subject: Re: st: bootstrap error: insufficient observations ...
>
> - --- Guido Heineck <guido.heineck@gmx.net> wrote:
> > I run a multinomial logit model and want to examine differences in 
> > predicted probabilities for different hypothetical groups of my
> > sample. Using the auto-data, the following code shows what I do.
> <snip>
>
> > I tried several things, but so far I was not successful. I would thus
> > appreciate any helpful hint.
> Try the following example:
>
> *------------ example -------------------------
> set more off
>
> sysuse auto, clear
> xtile lhs = price, nq(4)
> gen forXmpg = foreign * mpg
>
> capture program drop bst
> program bst, rclass
> 	mlogit lhs foreign mpg forXmpg
> 	preserve
> 	drop _all
> 	set obs 4
> 	gen foreign = _n <= 2
> 	gen mpg = cond(mod(_n,2),11,22)
> 	gen forXmpg = foreign * mpg
> 	predict pr*, pr
> 	return scalar diff11 = pr1[1]-pr1[3]
> 	return scalar diff13 = pr3[1]-pr3[3]
> 	return scalar diff21 = pr1[2]-pr1[4]
> 	return scalar diff23 = pr3[2]-pr3[4]
> 	restore
> end	
>
> tempfile res
> bootstrap diff11=r(diff11) diff13=r(diff13)  /*
>        */ diff21=r(diff21) diff23=r(diff23), /*
>        */ reps(100) saving(`res') seed(999): bst
> use `res', replace
> *------------ end example -------------------------
> (For more on how to use examples I sent to the Statalist, see
> http://home.fsw.vu.nl/m.buis/stata/exampleFAQ.html )
>
> Hope this helps,
> Maarten
>
> - -----------------------------------------
> Maarten L. Buis
> Department of Social Research Methodology
> Vrije Universiteit Amsterdam
> Boelelaan 1081
> 1081 HV Amsterdam
> The Netherlands
>
> visiting address:
> Buitenveldertselaan 3 (Metropolitan), room Z434
>
> +31 20 5986715
>
> http://home.fsw.vu.nl/m.buis/
> - -----------------------------------------
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