### Monday, March 20, 2006

## Re: st: looping

On Mar 20, 2006, at 9:42 AM, n j cox wrote:

> You should read some basic accounts of -by:-. > > Also, please note the advice in the Statalist FAQ: > > "Statalist is an international list. Please explain details that > may make sense only in your own corner of the world." > > Some of the details here presuppose knowledge of your local > situation, which I guess to be the United States. It is likely that > many members of Statalist do not know what "msa" means, for example. > > I am still in the dark on what an observation in your dataset > looks like, or what it represents. I assume that -males- and - > females- are numeric variables, but are they dummies or do they > include > counts? In either case, what is -perwt- precisely?

Sorry about the ambiguity. I did forget my audience. I am working with a special sample from the 2000 United States Census called the longform. It is a sample of households - I think approximately 5% of the US population received the survey. An observation is a household, but since only 5% of all households were sampled, you must use the person weights (-perwt-) when working with this data. So, for instance, if a certain household is sampled and they represent 5 households, then the perwt=5. Males and females are numeric values.

> > Either way, I guess that -egen, total()- with heavy use of -by()- > or -by:- is the easiest way to get totals of males and females, > after which you get ratios directly. It should take about 3 lines > of Stata. The only looping would be that tacit in -egen-.

I've been using egen to sum males and females, but was unsure of how to implement the looping over all US county variables. This is where -by county- wouuld come in, correct?

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Tag: statalist