Re: st: Nearmrg deleting unmerged observations

[Eric Booth <eric.a.booth@gmail.com>]

<>

Hi Lara:

You can merge your dataset back to the "master" dataset and keep all the observations - here's an example that expands on the example in the help file:


*******************
**1:  create 'using' data**
webuse autoexpense.dta, clear
rename make make2
sa "using.dta", replace


**2:  merge to auto.dta by price**
sysuse auto.dta, clear
sa "master.dta", replace
nearmrg  using "using.dta", upper nearvar(price) genmatch(usingmatch) limit(50)  
list make* price  usingmatch _m if inrange(_m, 3, 5)


drop _merge

**merge back to the master to get all the unmatched obs:
merge 1:1 make using "master.dta"
*******************


- Eric




On Jul 12, 2013, at 9:50 AM, Lara Loewenstein <lionstone@gmail.com> wrote:

> I'm using nearmrg to merge two datasets by street address. But I want
> an approximate merge for the street number while an exact merge for
> the street name. I also have multiple cities in the master dataset,
> while only one city in the using dataset, so I want to merge in the
> using dataset for that one city while keeping the unmerged
> observations in the master dataset. My code looks like this:
> 
> nearmrg street city using "UsingData", nearvar(stnum) limit(10)
> genmatch(using_stnum) update
> 
> The problem is, that when I do this, nearmrg automatically deletes all
> the unmerged data, so all i'm left with is a subset of the city in the
> using dataset that managed to merge with the master data.
> 
> How do I get nearmrg to keep all the observations, both merged and
> unmerged? I tried adding the keep option from the standard merge
> command, adding keep(1/5) since I'm updating a variable as well, but
> that caused nearmrg to delete all the observations and left me with an
> empty dataset.
> 
> Many thanks.
> 
> Lara Loewenstein
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