control.overlap: Assessing the number of control observations used in...

In SVMMatch: Causal Effect Estimation and Diagnostics with Support Vector Machines

Description

control.overlap returns a diagnostic plot showing the posterior mass over the number of control observations estimated in the common support region between the treatment and control groups.

Usage

	control.overlap(obj, color=TRUE, label.main="Assessing Control Overlap", 
		label.x="Size of Control Set", label.y="Mass")
	

Arguments

obj	A fitted SVMMatch object.
color	Whether to plot in color or black and white. TRUE or FALSE.
label.main	Main title for figure
label.x	X-axis label.
label.y	Y-axis label.

Details

Gives the posterior mass of control observations that fall in the common support region between treated and untreated obsevations. These are the only observations used in constructing the treatment effect.

Value

counts

Table containing posterior mass of number untreated observations.

Author(s)

Marc Ratkovic

References

Ratkovic, Marc. 2014. "Balancing within the Margin: Causal Effect Estimation with Support Vector Machines." Working paper.

See Also

svmmatch

Examples

## Not run: 
##See svmmatch() for a full implementation
##Load data
	data("LaLonde")
	Data1<-LaLonde
	Data1<-Data1[Data1$exper==0|Data1$treat==1,]
	attach(Data1)	

##Format X matrix
	varnames<-c("age","educ","black","married","nodegr","hisp",
		"re75","re74")
	X<-cbind(Data1[,varnames],Data1$re75==0,Data1$re74==0)
	X<-as.matrix(X)

##Fit model
	set.seed(1)
	m1.param<-svmmatch(treat, X, dv=re78, burnin=100, gibbs=100, thin=5)

##Assess ignorability:	
	#Assess control overlap--are there enough
	#controls to balance the treated?
		cont1<-control.overlap(m1.param)	

	
## End(Not run)

Example output

Warning messages:
1: In par(par.old) : graphical parameter "cin" cannot be set
2: In par(par.old) : graphical parameter "cra" cannot be set
3: In par(par.old) : graphical parameter "csi" cannot be set
4: In par(par.old) : graphical parameter "cxy" cannot be set
5: In par(par.old) : graphical parameter "din" cannot be set
6: In par(par.old) : graphical parameter "page" cannot be set

SVMMatch documentation built on May 2, 2019, 6:34 a.m.