negbinirr: Incidence rate ratios for a negative binomial regression.

Description

This function estimates a negative binomial regression model and calculates the corresponding incidence rate ratios.

Usage

negbinirr(formula, data, robust = FALSE, clustervar1 = NULL, 
          clustervar2 = NULL, start = NULL, control = glm.control())

Arguments

formula

an object of class ``formula'' (or one that can be coerced to that class).

data

the data frame containing these data. This argument must be used.

robust

if TRUE the function reports White/robust standard errors.

clustervar1

a character value naming the first cluster on which to adjust the standard errors.

clustervar2

a character value naming the second cluster on which to adjust the standard errors for two-way clustering.

start

starting values for the parameters in the glm.nb model.

control

see glm.control.

Value

irr

a coefficient matrix with columns containing the estimates, associated standard errors, test statistics and p-values.

fit

the fitted glm.nb object.

call

the matched call.

Details

If both robust=TRUE and !is.null(clustervar1) the function overrides the robust command and computes clustered standard errors.

Examples

Run this code

# NOT RUN {
# simulate some data
set.seed(12345)
n = 1000
x = rnorm(n)
y = rnegbin(n, mu = exp(1 + 0.5 * x), theta = 0.5)

data = data.frame(y,x)

negbinirr(formula=y~x,data=data)
# }