% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/xtfifevd-package.R
\docType{package}
\name{xtfifevd-package}
\alias{xtfifevd-package}
\title{xtfifevd: Panel Fixed Effects Filtered and Variance Decomposition Estimation}
\description{
Implements fixed effects estimators for time-invariant variables in panel
data models. Standard fixed effects (FE) estimation cannot identify
coefficients on time-invariant regressors because they are collinear with
the individual fixed effects. This package provides three methods to estimate
these coefficients:
}
\section{Methods}{

\describe{
\item{FEVD}{Fixed Effects Vector Decomposition (Plümper & Troeger, 2007).
A three-stage estimator that decomposes the unit effects into explained
(by time-invariant variables) and unexplained components.}
\item{FEF}{Fixed Effects Filtered (Pesaran & Zhou, 2016). A two-stage
estimator that regresses time-averaged FE residuals on time-invariant
variables.}
\item{FEF-IV}{Fixed Effects Filtered with Instrumental Variables
(Pesaran & Zhou, 2016). Uses external instruments when time-invariant
variables are endogenous.}
}
}

\section{Variance Estimation}{

All methods use the Pesaran-Zhou (2016) variance estimator (Equation 17 for
FEF/FEVD, Equation 51 for FEF-IV). These correct variance estimators account
for the generated regressor problem and avoid the severe size distortions
documented for naive pooled OLS standard errors.
}

\references{
Plumper, T., & Troeger, V. E. (2007). Efficient Estimation of Time-Invariant
and Rarely Changing Variables in Finite Sample Panel Analyses with Unit Fixed
Effects. \emph{Political Analysis}, 15(2), 124-139.
\doi{10.1093/pan/mpm002}

Pesaran, M. H., & Zhou, Q. (2018). Estimation of time-invariant effects in
static panel data models. \emph{Econometric Reviews}, 37(10), 1137-1171.
\doi{10.1080/07474938.2016.1222225}

Greene, W. H. (2011). Fixed Effects Vector Decomposition: A Magical Solution
to the Problem of Time-Invariant Variables in Fixed Effects Models?
\emph{Political Analysis}, 19(2), 135-146.
\doi{10.1093/pan/mpq034}
}
\author{
\strong{Maintainer}:  

}
\keyword{internal}
