residuals.ivmodel {ivmodel}

Residuals from the Fitted Model in the ivmodel Object

Description

This function returns the residuals from the k-Class estimators inside the ivmodel object.

Usage

## S3 method for class 'ivmodel'
residuals(object,...)
## S3 method for class 'ivmodel'
resid(object,...)

Arguments

object

ivmodel object.

...

Additional arguments to residuals or resid.

Value

A matrix of residuals for each k-Class estimator. Specifically, each column of the matrix represents residuals for each individual based on different estimates of the treatment effect from k-Class estimators. By default, one of the columns of the matrix is the residuals when the treatment effect is estimated by ordinarly least squares (OLS). Because OLS is generally biased in instrumental variables settings, the residuals will likely be biased.

Author(s)

Yang Jiang, Hyunseung Kang, and Dylan Small

See Also

See also ivmodel for details on the instrumental variables model.

Examples

data(card.data)
Y=card.data[,"lwage"]
D=card.data[,"educ"]
Z=card.data[,"nearc4"]
Xname=c("exper", "expersq", "black", "south", "smsa", "reg661", 
        "reg662", "reg663", "reg664", "reg665", "reg666", "reg667", 
		"reg668", "smsa66")
X=card.data[,Xname]
foo = ivmodel(Y=Y,D=D,Z=Z,X=X)
resid(foo)
residuals(foo)