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From |
"Dimitriy V. Masterov" <dvmaster@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: collapse with multiple sets of weights |

Date |
Thu, 12 Apr 2012 16:58:05 -0400 |

Scott, That's very clever and easy. Thanks. DVM On Thu, Apr 12, 2012 at 11:55 AM, Scott Merryman <scott.merryman@gmail.com> wrote: > Normalize the weights to sum to n and rescale population so the > weighting cancels out: > > clear > input pop avgwage > 10 20 > 20 10 > 40 30 > end > > egen double w=total(pop) > replace w=3*pop/w > gen double pop2 =pop/w^2 > collapse (sum) pop2 (mean) avgwage [w=w] > l > > > Scott > > > On Thu, Apr 12, 2012 at 10:05 AM, Dimitriy V. Masterov > <dvmaster@gmail.com> wrote: >> I am trying to aggregate some spatial data. Here's a simplified >> version of my problem. I have two variables, average wage and >> population, in three areas. I would like to sum the population, but >> calculate a weighted mean of the average wage. Is there a way to do >> this in one step using collapse? >> >> For example, the following code gets the mean right, but the population "wrong": >> set obs 3; >> input >> pop avgwage; >> 10 20; >> 20 10; >> 40 30; >> egen double w=total(pop); >> replace w=pop/w; >> collapse (sum) pop (mean) avgwage [w=w]; >> >> I would like to see 70, not 90. >> >> Is there a collapse-like command where I apply the weight only to the >> mean calculation? I suppose I could do this in two collapse steps, but >> that seems clunky. >> >> DVM > > * > * 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: collapse with multiple sets of weights***From:*"Dimitriy V. Masterov" <dvmaster@gmail.com>

**Re: st: collapse with multiple sets of weights***From:*Scott Merryman <scott.merryman@gmail.com>

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