Importacion de datos

library(wooldridge)
data(hprice1)
head(force(hprice1),n=5)
##   price assess bdrms lotsize sqrft colonial   lprice  lassess llotsize   lsqrft
## 1   300  349.1     4    6126  2438        1 5.703783 5.855359 8.720297 7.798934
## 2   370  351.5     3    9903  2076        1 5.913503 5.862210 9.200593 7.638198
## 3   191  217.7     3    5200  1374        0 5.252274 5.383118 8.556414 7.225482
## 4   195  231.8     3    4600  1448        1 5.273000 5.445875 8.433811 7.277938
## 5   373  319.1     4    6095  2514        1 5.921578 5.765504 8.715224 7.829630

Estimando el modelo

library(stargazer)
modelo_1<-lm(formula = price~lotsize+sqrft+bdrms, data = hprice1)
stargazer(modelo_1, title = 'Modelo Estimado', type= 'text')
## 
## Modelo Estimado
## ===============================================
##                         Dependent variable:    
##                     ---------------------------
##                                price           
## -----------------------------------------------
## lotsize                      0.002***          
##                               (0.001)          
##                                                
## sqrft                        0.123***          
##                               (0.013)          
##                                                
## bdrms                         13.853           
##                               (9.010)          
##                                                
## Constant                      -21.770          
##                              (29.475)          
##                                                
## -----------------------------------------------
## Observations                    88             
## R2                             0.672           
## Adjusted R2                    0.661           
## Residual Std. Error      59.833 (df = 84)      
## F Statistic           57.460*** (df = 3; 84)   
## ===============================================
## Note:               *p<0.1; **p<0.05; ***p<0.01

Pruebas de normalidad de los residuos

library(fitdistrplus)
ajuste_normal<-fitdist(data = modelo_1$residuals, distr = 'norm')
plot(ajuste_normal)

summary(ajuste_normal)
## Fitting of the distribution ' norm ' by maximum likelihood 
## Parameters : 
##          estimate Std. Error
## mean 9.992007e-16   6.231624
## sd   5.845781e+01   4.406424
## Loglikelihood:  -482.8775   AIC:  969.7549   BIC:  974.7096 
## Correlation matrix:
##      mean sd
## mean    1  0
## sd      0  1

Prueba de Normalidad de Jarque - Bera

library(normtest)
jb.norm.test(modelo_1$residuals)
## 
##  Jarque-Bera test for normality
## 
## data:  modelo_1$residuals
## JB = 32.278, p-value = 0.002
qqnorm(modelo_1$residuals)
qqline(modelo_1$residuals)

library(fastGraph)
shadeDist(32.278,ddist = 'dchisq',parm1 = qchisq(0.01,2,lower.tail = FALSE),lower.tail = FALSE)

Prueba de Normalidad de Kolmogorov - Smirnov

library(nortest)
lillie.test(modelo_1$residuals)
## 
##  Lilliefors (Kolmogorov-Smirnov) normality test
## 
## data:  modelo_1$residuals
## D = 0.075439, p-value = 0.2496
qqnorm(modelo_1$residuals)
qqline(modelo_1$residuals)

hist(modelo_1$residuals,main = "Histograma de los residuos",xlab = "Residuos",ylab = "frecuencia") 

Prueba de Normalidad de Shapiro - Wilk

shapiro.test(modelo_1$residuals)
## 
##  Shapiro-Wilk normality test
## 
## data:  modelo_1$residuals
## W = 0.94132, p-value = 0.0005937
qqnorm(modelo_1$residuals)
qqline(modelo_1$residuals)

library(fastGraph)
shadeDist(0.94132,parm1 = 0,ddist ="dnorm",lower.tail = F)