Ders 2

Veri Ölçeğinin SEKK İstatiskilerine Etkileri

library(wooldridge)
data(bwght, package = 'wooldridge')

library(rmarkdown)
paged_table(bwght)

\[\hat{bwght}= \hat{\beta }_0 + \hat{\beta }_1 \cdot cigs + \hat{\beta }_2 faminc \] Birinci regresyon

lm(bwght ~ cigs + faminc, data = bwght)

## 
## Call:
## lm(formula = bwght ~ cigs + faminc, data = bwght)
## 
## Coefficients:
## (Intercept)         cigs       faminc  
##   116.97413     -0.46341      0.09276

lm(bwght$bwght ~ bwght$cigs + bwght$faminc)

## 
## Call:
## lm(formula = bwght$bwght ~ bwght$cigs + bwght$faminc)
## 
## Coefficients:
##  (Intercept)    bwght$cigs  bwght$faminc  
##    116.97413      -0.46341       0.09276

İkinci regresyon

Doğum ağırlıklarını ons yerine pound cinsinden ölçtüğünüzde ne değişir?

bwght$bwghtlbs <- bwght$bwght / 16

lm(bwght$bwghtlbs ~ bwght$cigs + bwght$faminc)

## 
## Call:
## lm(formula = bwght$bwghtlbs ~ bwght$cigs + bwght$faminc)
## 
## Coefficients:
##  (Intercept)    bwght$cigs  bwght$faminc  
##     7.310883     -0.028963      0.005798

lm(I(bwght/16) ~ cigs + faminc, data = bwght)

## 
## Call:
## lm(formula = I(bwght/16) ~ cigs + faminc, data = bwght)
## 
## Coefficients:
## (Intercept)         cigs       faminc  
##    7.310883    -0.028963     0.005798

Üçüncü regresyon

lm(bwght ~ I(cigs/20) + faminc, data = bwght)

## 
## Call:
## lm(formula = bwght ~ I(cigs/20) + faminc, data = bwght)
## 
## Coefficients:
## (Intercept)   I(cigs/20)       faminc  
##   116.97413     -9.26815      0.09276

model_1<- lm(bwght ~ cigs + faminc, data = bwght)

model_2<- lm(I(bwght/16) ~ cigs + faminc, data = bwght)

model_3<- lm(bwght ~ I(cigs/20) + faminc, data = bwght)

library(stargazer)

## 
## Please cite as:

##  Hlavac, Marek (2022). stargazer: Well-Formatted Regression and Summary Statistics Tables.

##  R package version 5.2.3. https://CRAN.R-project.org/package=stargazer

stargazer(list(model_1,model_2,model_3), type = "text")

## 
## =================================================================
##                                        Dependent variable:       
##                                 ---------------------------------
##                                   bwght    I(bwght/16)   bwght   
##                                    (1)         (2)        (3)    
## -----------------------------------------------------------------
## cigs                            -0.463***   -0.029***            
##                                  (0.092)     (0.006)             
##                                                                  
## I(cigs/20)                                             -9.268*** 
##                                                         (1.832)  
##                                                                  
## faminc                           0.093***   0.006***    0.093*** 
##                                  (0.029)     (0.002)    (0.029)  
##                                                                  
## Constant                        116.974***  7.311***   116.974***
##                                  (1.049)     (0.066)    (1.049)  
##                                                                  
## -----------------------------------------------------------------
## Observations                      1,388       1,388      1,388   
## R2                                0.030       0.030      0.030   
## Adjusted R2                       0.028       0.028      0.028   
## Residual Std. Error (df = 1385)   20.063      1.254      20.063  
## F Statistic (df = 2; 1385)      21.274***   21.274***  21.274*** 
## =================================================================
## Note:                                 *p<0.1; **p<0.05; ***p<0.01