Hello, I have the data set below. This is a data set of total number of visits to the emergency room by region in the US. I want to implement a DiD method to see if the Medicare expansion in 2014 lowered the number of emergency hospital visits in the Northeast region, but I am having trouble generating a graph showing the parallel trends. Northeast is coded as 1 and South is coded as 3. I want to generate a graph plotting the totalvisits by region through time. So X-axis totalvisits, y-axis years and two lines one for Region=1 and Region=3.


Code:
* Example generated by -dataex-. To install: ssc install dataex
clear
input float totalvisits double(VMONTH VYEAR REGION) float treatment
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
1502 1 2008 1 0
end
label values VMONTH VMONTHF
label def VMONTHF 1 "January", modify
label values REGION REGIONF
label def REGIONF 1 "Northeast", modify