cluster.bs.ivreg: Pairs Cluster Bootstrapped p-Values For Regression With Instrumental Variables

Description

This software estimates p-values using pairs cluster bootstrapped t-statistics for instrumental variables regression models (Cameron, Gelbach, and Miller 2008). The data set is repeatedly re-sampled by cluster, a model is estimated, and inference is based on the sampling distribution of the pivotal (t) statistic.

Usage

cluster.bs.ivreg(mod, dat, cluster, ci.level = 0.95, boot.reps = 1000,
  stratify = FALSE, cluster.se = TRUE, report = TRUE,
  prog.bar = TRUE, output.replicates = FALSE, seed = NULL)

Arguments

mod

A model estimated using ivreg.

dat

The data set used to estimate mod.

cluster

A formula of the clustering variable.

ci.level

What confidence level should CIs reflect?

boot.reps

The number of bootstrap samples to draw.

stratify

Sample clusters only (= FALSE) or clusters and observations by cluster (= TRUE).

cluster.se

Use clustered standard errors (= TRUE) or ordinary SEs (= FALSE) for bootstrap replicates.

report

Should a table of results be printed to the console?

prog.bar

Show a progress bar of the bootstrap (= TRUE) or not (= FALSE).

output.replicates

Should the cluster bootstrap coefficient replicates be output (= TRUE) or not (= FALSE)?

seed

Random number seed for replicability (default is NULL).

Value

A list with the elements

p.values

A matrix of the estimated p-values.

A matrix of confidence intervals.

replicates

Optional: A matrix of the coefficient estimates from each cluster bootstrap replicate.

References

Esarey, Justin, and Andrew Menger. 2017. "Practical and Effective Approaches to Dealing with Clustered Data." Political Science Research and Methods forthcoming: 1-35. <URL:http://jee3.web.rice.edu/cluster-paper.pdf>.

Cameron, A. Colin, Jonah B. Gelbach, and Douglas L. Miller. 2008. "Bootstrap-Based Improvements for Inference with Clustered Errors." The Review of Economics and Statistics 90(3): 414-427. <DOI:10.1162/rest.90.3.414>.

Examples

Run this code

# NOT RUN {
##############################################
# example one: predict cigarette consumption
##############################################
require(AER)
data("CigarettesSW", package = "AER") 
CigarettesSW$rprice <- with(CigarettesSW, price/cpi)
CigarettesSW$rincome <- with(CigarettesSW, income/population/cpi)
CigarettesSW$tdiff <- with(CigarettesSW, (taxs - tax)/cpi)
fm <- ivreg(log(packs) ~ log(rprice) + log(rincome) | 
    log(rincome) + tdiff + I(tax/cpi), data = CigarettesSW)

# compute pairs cluster bootstrapped p-values
cluster.bs.c <- cluster.bs.ivreg(fm, dat = CigarettesSW, cluster = ~state, report = T)


################################################
# example two: pooled IV analysis of employment
################################################
require(plm)
require(AER)
data(EmplUK)
EmplUK$lag.wage <- lag(EmplUK$wage)
emp.iv <- ivreg(emp ~ wage + log(capital+1) | output + lag.wage + log(capital+1), data = EmplUK)

# compute cluster-adjusted p-values
cluster.bs.e <- cluster.bs.ivreg(mod = emp.iv, dat = EmplUK, cluster = ~firm)

# }

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