sampleSelection (version 1.0-4)

coef.selection: Extract Coefficients from Selection Models

Description

This function extracts coefficients from sample selection models

Usage

"coef"(object, part = "full", ...)
"coef"(object, part = "full", ...)
"print"( x, prefix = TRUE, digits = max(3, getOption("digits") - 3), ... )

Arguments

object

object of class selection or summary.selection.

part

character string indication which parts to extract: "full" for all estimated parameters (selection estimates, outcome estimates, error variance and correlation) or "outcome" for the outcome estimates only (including the coefficient of the inverse Mill's ratio in case of a two-step estimation).

x

object returned by coef.selection.

prefix

logical. Add a prefix to the names of the coefficients that indicates to which equation the coefficient belongs.

digits

numeric, (suggested) number of significant digits.

...

currently not used.

Value

coef.selection returns a vector of the estimated coefficients.coef.summary.selection returns a matrix of the estimated coefficients, their standard errors, t-values, and p-values.

See Also

coef, selection, vcov.selection, and selection-methods.

Examples

## Estimate a simple female wage model taking into account the labour
## force participation
   data(Mroz87)
   a <- heckit(lfp ~ huswage + kids5 + mtr + fatheduc + educ + city,
               log(wage) ~ educ + city, data=Mroz87)
## extract all coefficients of the model:
coef( a )

## now extract the coefficients of the outcome model only:
coef( a, part="outcome")

## extract all coefficients, standard errors, t-values
## and p-values of the model:
coef( summary( a ) )

## now extract the coefficients, standard errors, t-values
## and p-values of the outcome model only:
coef( summary( a ), part="outcome")