designmatch (version 0.5.4)

ecdfplot: Empirical cumulative distribution function plot for assessing covariate balance

Description

Function that plots the empirical cumulative distribution function of a given covariate for treated units and matched controls. ecdfplot can be used to visually inspect the balance of the entire empirical distribution function of the covariate in question.

Usage

ecdfplot(x, t_id, c_id, main_title = "", legend_position = "right")

Arguments

x

a covariate vector to be used to assess balance.

t_id

a vector of indexes of the treated units.

c_id

a vector of indexes of the matched controls.

main_title

a string defining the main title of the plot.

legend_position

a string specifying the position of the legend. The default is right. Other options are: topright, bottomright, bottom, bottomleft, left, topleft, top and center

Author

Jose R. Zubizarreta <[e-mail]>, Cinar Kilcioglu <[e-mail]>.

Details

Function that plots the empirical cumulative distribution function of a given covariate for treated units and matched controls. ecdfplot can be used to visually inspect the balance of the entire empirical distribution function of the covariate in question.

Examples

	# Load data
	data(germancities)

	# Sort and attach data
	germancities = germancities[order(germancities$treat, decreasing = TRUE), ]
	attach(germancities)

	# Treatment indicator
	t_ind = treat
	
	# Indexes of the treated units
	t_id = which(t_ind == 1)
		
	# Indexes of the controls before matching
	c_id_before = which(t_ind == 0)
	
	# Indixes of the matched controls (obtained using bmatch in designmatch)
	c_id_after = c(80, 82, 35, 59, 69, 68, 34, 62, 104, 61, 106, 120, 56, 119, 28, 
	113, 76, 118, 75, 71)
	
	# ecdfplot
	par(mfrow = c(2, 1))
	ecdfplot(rubble, t_id, c_id_before, "Before matching")
	ecdfplot(rubble, t_id, c_id_after, "After matching")