Distance to Border Variable (for Spacial RDD)

[Cat Santos]

Hello Everyone!

I am trying to create a variable corresponding to the distance from each municipality to a border (which includes a group of municipalities).

However, I do not know how to create a border polygon using stata.

I ran to get the coordinates dataset.

shp2dta using data12, database(CountryMap) coordinates(municoord) genid(identi)

And then I attempted to create the polygon corresponding to my "treatment" area:

rename FID _ID

mergepoly if inlist(province,"a","b","c", "d", ///
"e", "f", "g", "h") using "municoord.dta", coor(merged_coord) replace

mergepoly if inlist(muni_name,"m1", "m2", "m3", ///
"m4", "m5", "m6", "m7","m8") using "municoord.dta", coor(merged_coord2) replace

I manually merged the two datasets created by mergepoly.

However, now I do not know how to create a variable corresponding to the distance between each municipality and the border of the polygon I created.

Thank you very much.

Best,
Cat

[Jared Greathouse]

https://www.statalist.org/forums/for...nt-to-a-border

[Cat Santos]

Thank you Jared. I was actually reading through the link you sent (and also this example), but I still can't understand if I created the "treatment" polygon correctly, and how to create the distance between the polygon's border and each municipality...

[Cat Santos]

May I just write a follow up question: can spatial RDDs have two non-contiguous “treatment” areas? For example, a treated area including provinces in the north of a country, and a treated area including provinces in the south of a country?

Thank you very much!

Cat

[Jared Greathouse]

Yeah it can. Say we have Cobb county Georgia as treated and Coweta County Georgia as treated. We can still do spatial RDD since we're estimating the LATE with respect to other houses/areas within some cutoff from the border... at least, I'm pretty sure this is true

[Cat Santos]

Dear Jared,
Thank you so much! This was really helpful.

Best,
Cat