Aplicacion para modelos corregidos estimadores HAC

UNIVERCIDAD DE EL SALVADOR

FACULDAD DE CIENCIAS ECONOMICAS

Docente: Carlos Ademir Perez Alas

Alumna: Marta Abigail Meza Robles

DUE: MR21132

Carga de datos

load("C:/Users/abyme/Downloads/Marta Abigail Meza Robles - smoke.RData")

Modelo a Estimar

options(scipen = 9999999)
library(foreign)
modelo<-lm(cigs~cigpric+lcigpric+income+lincome+age+agesq+educ+white+restaurn,data = data)
print(modelo)
## 
## Call:
## lm(formula = cigs ~ cigpric + lcigpric + income + lincome + age + 
##     agesq + educ + white + restaurn, data = data)
## 
## Coefficients:
##   (Intercept)        cigpric       lcigpric         income        lincome  
##  340.80437460     2.00226767  -115.27346445    -0.00004619     1.40406118  
##           age          agesq           educ          white       restaurn  
##    0.77835901    -0.00915035    -0.49478062    -0.53105164    -2.64424135
library(equatiomatic)
equatiomatic::extract_eq(modelo)

\[ \operatorname{cigs} = \alpha + \beta_{1}(\operatorname{cigpric}) + \beta_{2}(\operatorname{lcigpric}) + \beta_{3}(\operatorname{income}) + \beta_{4}(\operatorname{lincome}) + \beta_{5}(\operatorname{age}) + \beta_{6}(\operatorname{agesq}) + \beta_{7}(\operatorname{educ}) + \beta_{8}(\operatorname{white}) + \beta_{9}(\operatorname{restaurn}) + \epsilon \]

Resumen del modelo con stargazer

options(scipen = 999999)
library(stargazer)
modelo_Hac<-lm(cigs~cigpric+lcigpric+income+lincome+age+agesq+educ+white+restaurn,data = data)
stargazer(modelo,type = "html",title = "Modelo para estimadores HAC")
Modelo para estimadores HAC
Dependent variable:
cigs
cigpric 2.002
(1.493)
lcigpric -115.273
(85.424)
income -0.00005
(0.0001)
lincome 1.404
(1.708)
age 0.778***
(0.161)
agesq -0.009***
(0.002)
educ -0.495***
(0.168)
white -0.531
(1.461)
restaurn -2.644**
(1.130)
Constant 340.804
(260.016)
Observations 807
R2 0.055
Adjusted R2 0.044
Residual Std. Error 13.413 (df = 797)
F Statistic 5.169*** (df = 9; 797)
Note: p<0.1; p<0.05; p<0.01

Verifique si la matriz de Varianza-Covarianza del modelo es escalar, de no ser escalar indique la fuente del problema.

Prueba de White (prueba de Breusch Pagan)

library(lmtest)
white_test<-bptest(modelo,~I(cigpric^2)+I(lcigpric^2)+I(income^2)+I(lincome^2)+I(age^2)+I(agesq^2)+I(educ^2)+I(white^2)+I(restaurn^2)+(cigpric*lcigpric)+(cigpric*income)+(cigpric*lincome)+(cigpric*age)+(cigpric*agesq)+(cigpric*educ)+(cigpric*white),data = data)
print(white_test)
## 
##  studentized Breusch-Pagan test
## 
## data:  modelo
## BP = 42.143, df = 21, p-value = 0.004037

Existe evidencia de que la varianza de los residuos es heterocedastica ya que p-value < 0.05

Prueba del Multiplicador de Lagrange (Breusch Godfrey)

Autocorrelación de 2º Orden:

library(lmtest)
prueba_LM<-bgtest(modelo,order = 2)
print(prueba_LM)
## 
##  Breusch-Godfrey test for serial correlation of order up to 2
## 
## data:  modelo
## LM test = 0.26889, df = 2, p-value = 0.8742

No hay evidencia de Autocorrelación de 2º orden ya que pvalue > 0.05

Autocorrelación de 1º orden (prueba de Durbin Watson)

library(car)
durbinWatsonTest(model = modelo)
##  lag Autocorrelation D-W Statistic p-value
##    1    -0.009243664      2.017442   0.862
##  Alternative hypothesis: rho != 0

No hay evidencia de Autocorrelación de 1º orden ya que pvalue>0.05

Estimador HAC apropiado y denominelo vcov_HAC

Sin corregir

options(scipen = 99999)
library(lmtest)
#Sin corregir:
coeftest(modelo)
## 
## t test of coefficients:
## 
##                   Estimate     Std. Error t value     Pr(>|t|)    
## (Intercept)  340.804374604  260.015587269  1.3107     0.190334    
## cigpric        2.002267667    1.492831189  1.3413     0.180220    
## lcigpric    -115.273464445   85.424315195 -1.3494     0.177585    
## income        -0.000046194    0.000133491 -0.3460     0.729402    
## lincome        1.404061178    1.708165841  0.8220     0.411340    
## age            0.778359013    0.160555612  4.8479 0.0000015001 ***
## agesq         -0.009150353    0.001749292 -5.2309 0.0000002158 ***
## educ          -0.494780616    0.168180198 -2.9420     0.003356 ** 
## white         -0.531051635    1.460721806 -0.3636     0.716287    
## restaurn      -2.644241351    1.129998690 -2.3400     0.019528 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Corregido (usando un estimador HAC)

options(scipen = 99999)
library(lmtest)
library(sandwich)
#Corregido
#HC0 Corrige Sólo Heterocedasticidad, use HC1 para corregir también Autocorrelación de Primer
vcov_HAC<-vcovHC(modelo,type = "HC0") 

coeftest(modelo,vcov. = vcov_HAC)
## 
## t test of coefficients:
## 
##                   Estimate     Std. Error t value        Pr(>|t|)    
## (Intercept)  340.804374604  278.565072832  1.2234        0.221530    
## cigpric        2.002267667    1.602727983  1.2493        0.211927    
## lcigpric    -115.273464445   91.344424868 -1.2620        0.207331    
## income        -0.000046194    0.000115593 -0.3996        0.689540    
## lincome        1.404061178    1.228970726  1.1425        0.253602    
## age            0.778359013    0.136944678  5.6837 0.0000000184838 ***
## agesq         -0.009150353    0.001451548 -6.3039 0.0000000004804 ***
## educ          -0.494780616    0.162968371 -3.0361        0.002475 ** 
## white         -0.531051635    1.361907703 -0.3899        0.696691    
## restaurn      -2.644241351    1.038254938 -2.5468        0.011058 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Usando la libreria stargazer, presente el modelo “original” y el modelo “corregido” en una sola tabla (consulte la documentación de stargazer)

library(stargazer)
library(sandwich)

vcov_HAC<-vcovHC(modelo,type="HC0")
robust.se<-sqrt(diag(vcov_HAC))

stargazer(modelo,modelo, 
          se=list(NULL, robust.se),
          column.labels=c("Modelo Original","Modelo Corregido"), 
          align=TRUE,
          type = "html",title = "Modelo de consumo")
Modelo de consumo
Dependent variable:
cigs
Modelo Original Modelo Corregido
(1) (2)
cigpric 2.002 2.002
(1.493) (1.603)
lcigpric -115.273 -115.273
(85.424) (91.344)
income -0.00005 -0.00005
(0.0001) (0.0001)
lincome 1.404 1.404
(1.708) (1.229)
age 0.778*** 0.778***
(0.161) (0.137)
agesq -0.009*** -0.009***
(0.002) (0.001)
educ -0.495*** -0.495***
(0.168) (0.163)
white -0.531 -0.531
(1.461) (1.362)
restaurn -2.644** -2.644**
(1.130) (1.038)
Constant 340.804 340.804
(260.016) (278.565)
Observations 807 807
R2 0.055 0.055
Adjusted R2 0.044 0.044
Residual Std. Error (df = 797) 13.413 13.413
F Statistic (df = 9; 797) 5.169*** 5.169***
Note: p<0.1; p<0.05; p<0.01