rm(list=ls())


pdf("Diff-Diff.pdf")
plot(c(0,0),c(2,2),type="n",xlim=c(1,3),ylim=c(0,3),xlab="",
    ylab="",yaxt="n",xaxt="n")
axis(1,at=c(1,2.5),labels=c("1","2"),cex.axis=1.5,col.axis="purple") 
segments(1,1.5,2.5,3,col="purple",lwd=3)
segments(1,0.5,2.5,1,col="purple",lwd=3)
segments(1,1.5,2.5,2,col="purple",lty=2,lwd=3)


text(2.5,2.7,expression(bar(Y)[2]),col="red",cex=1.53)    
text(2.75,2.7,"(Treated)",col="red",cex=1.53)   ## finqui

text(1.2,1.35,expression(bar(Y)[1]),col="red",cex=1.53)
text(1.45,1.35,"(Treated)",col="red",cex=1.53)

text(1.2,0.3,expression(bar(Z)[1]),cex=1.53)
text(1.45,0.3,"(Control)",cex=1.53)

text(2.5,.7,expression(bar(Z)[2]),cex=1.53)
text(2.75,.7,"(Control)",cex=1.53)

mtext("time",side=1,line=1,cex=1.5,adj=.9)
mtext("Y",side=2,line=2,cex=1.5)
 

dev.off()