apollo (version 0.2.6)

apollo_deltaMethod: Delta method

Description

Applies the delta method to calculate the standard errors of transformations of parameters. If the bootstrap covariance matrix is available, it is used. If not, the robust covariance matrix is used.

Usage

apollo_deltaMethod(model, deltaMethod_settings)

Arguments

model

Model object. Estimated model object as returned by function apollo_estimate.

deltaMethod_settings

List of arguments. It must contain the following.

• operation: Character. Function to calculate the delta method for. See details.

• parName1: Character. Name of the first parameter.

• parName2: Character. Name of the second parameter. Optional depending on operation.

• multPar1: Numeric scalar. A value to scale parName1.

• multPar2: Numeric scalar. A value to scale parName2.

Value

Matrix contating calue, s.e. and t-ratio resulting from the operation. This is also printed to screen.

Details

apollo_deltaMethod supports the following five operations.

sum

Calculates the s.e. of parName1 + parName2

diff

Calculates the s.e. of parName1 - parName2 and parName2 - parName1

prod

Calculates the s.e. of parName1*parName2

ratio

Calculates the s.e. of parName1/parName2 and parName2/parName1

exp

Calculates the s.e. of exp(parName1)

logistic

If only parName1 is provided, it calculates the s.e. of exp(parName1)/(1+exp(parName1)) and 1/(1+exp(parName1)). If parName1 and parName2 are provided, it calculates exp(par_i)/(1+exp(parName1)+exp(parName2)) for i=1, 2, and 3 (par_3 = 1).

lognormal

Calculates the mean and s.d. of a lognormal distribution based on the mean (parName1) and s.d. (parName2) of the underlying normal.