Modifier: la version de plm
CRAN 1.6-4 le à partir (Décembre 2016) comporte également les statistiques de test asymétriques dans plmtest()
.
Puisque ceci est résolu maintenant, je posterai une réponse ici. Le code est maintenant dans la version de développement de v1.15-16 plm
sur r-forge: https://r-forge.r-project.org/projects/plm/ et https://r-forge.r-project.org/R/?group_id=406
Voici comment reproduire un exemple de la documentation de Stata:
# get data set from STATA's webpage
# It is an unbalanced panel
require(haven) # required to read STATA data file
nlswork <- read_dta("http://www.stata-press.com/data/r14/nlswork.dta")
nlswork$race <- factor(nlswork$race) # fix data
nlswork$race2 <- factor(ifelse(nlswork$race == 2, 1, 0)) # need this variable for example
pnlswork <- pdata.frame(nlswork, index=c("idcode", "year"), drop.index=F)
# note STATA 14 uses by default a different method compared to plm's Swamy–Arora variance component estimator
# This is why in comparison with web examples from STATA the random effects coefficients slightly differ
plm_re_nlswork <- plm(ln_wage ~ grade + age + I(age^2) + ttl_exp + I(ttl_exp^2) + tenure + I(tenure^2) + race2 + not_smsa + south
, data = pnlswork, model = "random")
# reassembles the FE estimation by STATA in Example 2 of http://www.stata.com/manuals13/xtxtreg.pdf
plm_fe_nlswork <- plm(ln_wage ~ grade + age + I(age^2) + ttl_exp + I(ttl_exp^2) + tenure + I(tenure^2) + race2 + not_smsa + south
, data = pnlswork, model = "within")
plm_pool_nlswork <- plm(ln_wage ~ grade + age + I(age^2) + ttl_exp + I(ttl_exp^2) + tenure + I(tenure^2) + race2 + not_smsa + south
, data = pnlswork, model = "pooling")
# Run Breusch-Pagan test with modification for unbalanced panels of Baltahi/Li (1990)
# Reassembles Exmaple 1 in http://www.stata.com/manuals13/xtxtregpostestimation.pdf
plmtest(plm_pool_nlswork)
## Lagrange Multiplier Test - individual effects - Breusch-Pagan Test for unbalanced Panels as in Baltagi/Li (1990)
## data: ln_wage ~ grade + age + I(age^2) + ttl_exp + I(ttl_exp^2) + tenure + ...
## BP_unbalanced = 14779.98, df = 1, p-value < 0.00000000000000022
## alternative hypothesis: significant effects