Description Usage Arguments Details Value Author(s) References See Also Examples
Linear models for panel data estimated using the lm
function on
transformed data.
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formula,
data,
subset,
weights,
na.action,
effect = c("individual", "time", "twoways", "nested"),
model = c("within", "random", "ht", "between", "pooling", "fd"),
random.method = NULL,
random.models = NULL,
random.dfcor = NULL,
inst.method = c("bvk", "baltagi", "am", "bms"),
restrict.matrix = NULL,
restrict.rhs = NULL,
index = NULL,
...
)
## S3 method for class 'plm.list'
print(
x,
digits = max(3, getOption("digits") - 2),
width = getOption("width"),
...
)
## S3 method for class 'panelmodel'
terms(x, ...)
## S3 method for class 'panelmodel'
vcov(object, ...)
## S3 method for class 'panelmodel'
fitted(object, ...)
## S3 method for class 'panelmodel'
residuals(object, ...)
## S3 method for class 'panelmodel'
df.residual(object, ...)
## S3 method for class 'panelmodel'
coef(object, ...)
## S3 method for class 'panelmodel'
print(
x,
digits = max(3, getOption("digits") - 2),
width = getOption("width"),
...
)
## S3 method for class 'panelmodel'
update(object, formula., ..., evaluate = TRUE)
## S3 method for class 'panelmodel'
deviance(object, model = NULL, ...)
## S3 method for class 'plm'
predict(object, newdata = NULL, ...)
## S3 method for class 'plm'
formula(x, ...)
## S3 method for class 'plm'
plot(
x,
dx = 0.2,
N = NULL,
seed = 1,
within = TRUE,
pooling = TRUE,
between = FALSE,
random = FALSE,
...
)
## S3 method for class 'plm'
residuals(object, model = NULL, effect = NULL, ...)
## S3 method for class 'plm'
fitted(object, model = NULL, effect = NULL, ...)
|
formula |
a symbolic description for the model to be estimated, |
data |
a |
subset |
see |
weights |
see |
na.action |
see |
effect |
the effects introduced in the model, one of
|
model |
one of |
random.method |
method of estimation for the variance
components in the random effects model, one of |
random.models |
an alternative to the previous argument, the models used to compute the variance components estimations are indicated, |
random.dfcor |
a numeric vector of length 2 indicating which degree of freedom should be used, |
inst.method |
the instrumental variable transformation: one of
|
restrict.matrix |
a matrix which defines linear restrictions on the coefficients, |
restrict.rhs |
the right hand side vector of the linear restrictions on the coefficients, |
index |
the indexes, |
... |
further arguments. |
x, object |
an object of class |
digits |
number of digits for printed output, |
width |
the maximum length of the lines in the printed output, |
formula. |
a new formula for the update method, |
evaluate |
a boolean for the update method, if |
newdata |
the new data set for the |
dx |
the half–length of the individual lines for the plot method (relative to x range), |
N |
the number of individual to plot, |
seed |
the seed which will lead to individual selection, |
within |
if |
pooling |
if |
between |
if |
random |
if |
plm
is a general function for the estimation of linear panel
models. It supports the following estimation methods: pooled OLS
(model = "pooling"
), fixed effects ("within"
), random effects
("random"
), first–differences ("fd"
), and between
("between"
). It supports unbalanced panels and two–way effects
(although not with all methods).
For random effects models, four estimators of the transformation
parameter are available by setting random.method
to one of
"swar"
\insertCiteSWAM:AROR:72plm (default), "amemiya"
\insertCiteAMEM:71plm, "walhus"
\insertCiteWALL:HUSS:69plm, or "nerlove"
\insertCiteNERLO:71plm (see below for Hausman-Taylor instrumental
variable case).
For first–difference models, the intercept is maintained (which
from a specification viewpoint amounts to allowing for a trend in
the levels model). The user can exclude it from the estimated
specification the usual way by adding "-1"
to the model formula.
Instrumental variables estimation is obtained using two–part
formulas, the second part indicating the instrumental variables
used. This can be a complete list of instrumental variables or an
update of the first part. If, for example, the model is y ~ x1 + x2 + x3
, with x1
and x2
endogenous and z1
and z2
external
instruments, the model can be estimated with:
formula = y~x1+x2+x3 | x3+z1+z2
,
formula = y~x1+x2+x3 | . -x1-x2+z1+z2
.
If an instrument variable estimation is requested, argument
inst.method
selects the instrument variable transformation
method:
"bvk"
(default) for \insertCiteBALE:VARA:87;textualplm,
"baltagi"
for \insertCiteBALT:81;textualplm,
"am"
for \insertCiteAMEM:MACU:86;textualplm,
"bms"
for \insertCiteBREU:MIZO:SCHM:89;textualplm.
The Hausman–Taylor estimator \insertCiteHAUS:TAYL:81plm is
computed with arguments random.method = "ht"
, model = "random"
,
inst.method = "baltagi"
(the other way with only model = "ht"
is deprecated).
See also the vignettes for introductions to model estimations (and more) with examples.
An object of class "plm"
.
A "plm"
object has the following elements :
coefficients |
the vector of coefficients, |
vcov |
the variance–covariance matrix of the coefficients, |
residuals |
the vector of residuals (these are the residuals of the (quasi-)demeaned model), |
weights |
(only for weighted estimations) weights as specified, |
df.residual |
degrees of freedom of the residuals, |
formula |
an object of class |
model |
the model frame as a |
ercomp |
an object of class |
aliased |
named logical vector indicating any aliased
coefficients which are silently dropped by |
call |
the call. |
It has print
, summary
and print.summary
methods. The
summary
method creates an object of class "summary.plm"
that
extends the object it is run on with information about (inter alia) F
statistic and (adjusted) R-squared of model, standard errors, t–values, and
p–values of coefficients, (if supplied) the furnished vcov, see
summary.plm()
for further details.
Yves Croissant
AMEM:71plm
\insertRefAMEM:MACU:86plm
\insertRefBALE:VARA:87plm
\insertRefBALT:81plm
\insertRefBALT:SONG:JUNG:01plm
\insertRefBALT:13plm
\insertRefBREU:MIZO:SCHM:89plm
\insertRefHAUS:TAYL:81plm
\insertRefNERLO:71plm
\insertRefSWAM:AROR:72plm
\insertRefWALL:HUSS:69plm
summary.plm()
for further details about the associated
summary method and the "summary.plm" object both of which provide some model
tests and tests of coefficients. fixef()
to compute the fixed
effects for "within" models (=fixed effects models).
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 | data("Produc", package = "plm")
zz <- plm(log(gsp) ~ log(pcap) + log(pc) + log(emp) + unemp,
data = Produc, index = c("state","year"))
summary(zz)
# replicates some results from Baltagi (2013), table 3.1
data("Grunfeld", package = "plm")
p <- plm(inv ~ value + capital,
data = Grunfeld, model = "pooling")
wi <- plm(inv ~ value + capital,
data = Grunfeld, model = "within", effect = "twoways")
swar <- plm(inv ~ value + capital,
data = Grunfeld, model = "random", effect = "twoways")
amemiya <- plm(inv ~ value + capital,
data = Grunfeld, model = "random", random.method = "amemiya",
effect = "twoways")
walhus <- plm(inv ~ value + capital,
data = Grunfeld, model = "random", random.method = "walhus",
effect = "twoways")
# summary and summary with a furnished vcov (passed as matrix,
# as function, and as function with additional argument)
summary(wi)
summary(wi, vcov = vcovHC(wi))
summary(wi, vcov = vcovHC)
summary(wi, vcov = function(x) vcovHC(x, method = "white2"))
## nested random effect model
# replicate Baltagi/Song/Jung (2001), p. 378 (table 6), columns SA, WH
# == Baltagi (2013), pp. 204-205
data("Produc", package = "plm")
pProduc <- pdata.frame(Produc, index = c("state", "year", "region"))
form <- log(gsp) ~ log(pc) + log(emp) + log(hwy) + log(water) + log(util) + unemp
summary(plm(form, data = pProduc, model = "random", effect = "nested"))
summary(plm(form, data = pProduc, model = "random", effect = "nested",
random.method = "walhus"))
## Instrumental variable estimations
# replicate Baltagi (2013/2021), p. 133/162, table 7.1
data("Crime", package = "plm")
FE2SLS <- plm(lcrmrte ~ lprbarr + lpolpc + lprbconv + lprbpris + lavgsen +
ldensity + lwcon + lwtuc + lwtrd + lwfir + lwser + lwmfg + lwfed +
lwsta + lwloc + lpctymle + lpctmin + region + smsa + factor(year)
| . - lprbarr - lpolpc + ltaxpc + lmix,
data = Crime, model = "within")
G2SLS <- update(FE2SLS, model = "random", inst.method = "bvk")
EC2SLS <- update(G2SLS, model = "random", inst.method = "baltagi")
## Hausman-Taylor estimator and Amemiya-MaCurdy estimator
# replicate Baltagi (2005, 2013), table 7.4; Baltagi (2021), table 7.5
data("Wages", package = "plm")
ht <- plm(lwage ~ wks + south + smsa + married + exp + I(exp ^ 2) +
bluecol + ind + union + sex + black + ed |
bluecol + south + smsa + ind + sex + black |
wks + married + union + exp + I(exp ^ 2),
data = Wages, index = 595,
random.method = "ht", model = "random", inst.method = "baltagi")
summary(ht)
am <- plm(lwage ~ wks + south + smsa + married + exp + I(exp ^ 2) +
bluecol + ind + union + sex + black + ed |
bluecol + south + smsa + ind + sex + black |
wks + married + union + exp + I(exp ^ 2),
data = Wages, index = 595,
random.method = "ht", model = "random", inst.method = "am")
summary(am)
|
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