Notice: On March 31, it was **announced** that Statalist is moving from an email list to a **forum**. The old list will shut down on April 23, and its replacement, **statalist.org** is already up and running.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

From |
Kate Schneider <schneider.kate1@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: Replace with returned results in svy loop |

Date |
Sun, 29 May 2011 16:53:59 -0700 |

Thank you so much Richard! It totally works! We can't get it to only replace the missing values, but I think it is more valid to create a new variable with the estimated value anyways. Thanks so much! Kate On Sun, May 29, 2011 at 5:42 PM, Richard Williams <richardwilliams.ndu@gmail.com> wrote: > First off, you may not have e(mean), but you do have the matrix e(b), which > contains the mean of your variable. Sometimes you have to do something like > > mat list e(b) > > to see where values are stored. ereturn list doesn't show you what values > are stored in the matrices. > > As for how to handle missing data, I suggest taking a look at Paul Allison's > small book, "Missing Data," and reading through the Stata 11 documentation > on multiple imputation. Others who are more familiar with these methods can > perhaps advise you further. > > > At 06:27 PM 5/29/2011, Kate Schneider wrote: >> >> Thanks so much Richard, >> >> We are trying to monetize own consumption of food items, so the mean >> we are calculating is the average price reported by households who >> bought the food and we want to apply this to the missing data. >> Observations are missing where households ate food they produced >> themselves or did not report the price they paid for the item if they >> bought it. >> >> Is there a better way you recommend attributing these prices to the >> cases where we don't have a value? We were previously manually keeping >> track of the mean prices and then manually telling stata to replace >> (for example) price_eggs == $1 if price_eggs==. We are trying to avoid >> manually going between excel and stata, thinking that it would be more >> valid to have stata do all of this for us. >> >> The other approach we were considering would be to create a new >> variable where every observation of eggs get the mean egg price value, >> and then when we calculate the total value of egg consumption to >> specify drawing from the reported price if not missing, and if missing >> use the new value. Does that sound like a more valid approach? >> Regardless when we use ereturn list, there isn't a scalar listed for >> our mean. We tried e(mean), but it returned an error. Do we have to >> tell stata to store e(mean) before our svy: mean calculation? >> >> The other thing we should specify is that our data is hierarchical >> with 2 unique identifiers, a household ID and an id for each of the 65 >> different food items. We are trying to value total consumption per >> food item and also per household. We thought about collapsing food >> items to their mean price, but thought that probably wouldn't apply >> our survey weights (though perhaps stata is smarter than we are?). >> >> Thanks so much for your assistance, we are really grateful! >> >> Kate >> >> On Sun, May 29, 2011 at 5:11 PM, Richard Williams >> <richardwilliams.ndu@gmail.com> wrote: >> > If in doubt where a value is stored, type -ereturn list- after the >> > estimation command. After -mean-, e(b) has the mean of the variable. So, >> > to >> > get the mean stored in a scalar, do something like >> > >> > webuse nhanes2f, clear >> > svy: mean houssiz >> > mat varmean = e(b) >> > scalar vmean = varmean[1,1] >> > >> > Having said that, substituting the mean for missing data is generally >> > not >> > considered the best practice in the world. And, there may be other >> > errors in >> > your code (e.g. the == in the replace command looks wrong) but I imagine >> > those will become obvious once you tidy other things up. >> > >> > At 03:11 PM 5/29/2011, Kate Schneider wrote: >> >> >> >> Hello, >> >> Sorr to bug everyone on a holiday weekend, but we're a graduate >> >> student research group at the University of Washington working with a >> >> large household survey dataset and have come up against some trouble. >> >> >> >> We're trying to replace missing values of a variable with the results >> >> of some other operation we've just performed (basically, a mean). >> >> Right now, we're having trouble with the replace component of the >> >> below operation. Does anyone know how torecall the previous command's >> >> results from the svy calculation and use that data to replace missing >> >> in a loop? Is this possible with survey data? >> >> >> >> foreach X of varlist $fooditemall { >> >> quietly count if `X'==1 & priceperkilo !=. >> >> if `r(N)'>0 { >> >> display "Variable is: " "`X'" >> >> svy, subpop(`X'): mean priceperkilo >> >> } >> >> quietly count if `X'==1 & priceperkilo ==. >> >> if `r(N)'>0 { >> >> replace priceperkilo == e(????) if `X'==1 & priceperkilo ==. >> >> } >> >> } >> >> >> >> Thanks for your insight! If you need more information please let me >> >> know. >> >> Kate >> >> >> >> * >> >> * 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/ >> > >> > ------------------------------------------- >> > Richard Williams, Notre Dame Dept of Sociology >> > OFFICE: (574)631-6668, (574)631-6463 >> > HOME: (574)289-5227 >> > EMAIL: Richard.A.Williams.5@ND.Edu >> > WWW: http://www.nd.edu/~rwilliam >> > >> > * >> > * 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/ > > ------------------------------------------- > Richard Williams, Notre Dame Dept of Sociology > OFFICE: (574)631-6668, (574)631-6463 > HOME: (574)289-5227 > EMAIL: Richard.A.Williams.5@ND.Edu > WWW: http://www.nd.edu/~rwilliam > > * > * 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/

**Follow-Ups**:**Re: st: Replace with returned results in svy loop***From:*Richard Williams <richardwilliams.ndu@gmail.com>

**References**:**st: Replace with returned results in svy loop***From:*Kate Schneider <schneider.kate1@gmail.com>

**Re: st: Replace with returned results in svy loop***From:*Richard Williams <richardwilliams.ndu@gmail.com>

**Re: st: Replace with returned results in svy loop***From:*Kate Schneider <schneider.kate1@gmail.com>

**Re: st: Replace with returned results in svy loop***From:*Richard Williams <richardwilliams.ndu@gmail.com>

- Prev by Date:
**Re: st: Replace with returned results in svy loop** - Next by Date:
**Re: st: Replace with returned results in svy loop** - Previous by thread:
**Re: st: Replace with returned results in svy loop** - Next by thread:
**Re: st: Replace with returned results in svy loop** - Index(es):