Appendix

library(robustHD)

Loading required package: ggplot2
Loading required package: perry
Loading required package: parallel
Loading required package: robustbase
Warning messages:
1: R graphics engine version 12 is not supported by this version of RStudio. The Plots tab will be disabled until a newer version of RStudio is installed. 
2: In as.POSIXlt.POSIXct(x, tz) :
  unknown timezone 'zone/tz/2017c.1.0/zoneinfo/Europe/Helsinki'

library(readxl)

P/Net Sales

Beroende variabel: P/Net Sales
Oberoende Variabel: Ledare(1)

Deskriptiv statistik för P/Net Sales

Psales <- read_excel("~/Desktop/dataforr.xlsx")
summary(Psales$`P/Net Sales`)

    Min.  1st Qu.   Median     Mean  3rd Qu.     Max. 
  0.0098   0.5292   1.4505   3.8803   2.9703 361.3567 

Parametriskt test: T-test av P/Net Sales

Parametriskt test: Winsoriserat(5%) t-test av ‘P/Net Sales’

t.test(winsorize(Psales$`P/Net sales`) ~Psales$Leader, mu=0, alt="two.sided")

    Welch Two Sample t-test

data:  winsorize(Psales$`P/Net sales`) by Psales$Leader
t = 0.48236, df = 9.3824, p-value = 0.6406
alternative hypothesis: true difference in means is not equal to 0
95 percent confidence interval:
 -0.5379892  0.8319103
sample estimates:
mean in group 0 mean in group 1 
       1.667122        1.520162 

boxplot(winsorize(Psales$`P/Net sales`)~Psales$Leader)

Icke-parametriskt test: Mann-Whitney U-test

wilcox.test(Psales$`P/Net Sales`~Psales$Leader, mu=0, alt="two.sided", conf.int=T, conf.level=0.95, paired=F, exact=T,correct=T)

    Wilcoxon rank sum test

data:  Psales$`P/Net Sales` by Psales$Leader
W = 8528, p-value = 0.00741
alternative hypothesis: true location shift is not equal to 0
95 percent confidence interval:
 0.1133459 0.8774902
sample estimates:
difference in location 
             0.4418465 

P/EBITDA

Beroende variabel: P/EBITDA
Oberoende Variabel: Ledare(1)

Deskriptiv statistik för P/EBITDA

Pebitda <- read_excel("~/Documents/analysis/pebitda.xlsx")

summary(Psales$`P/EBITDA`)

     Min.   1st Qu.    Median      Mean   3rd Qu.      Max. 
 0.006476  0.564578  1.154221  2.278268  2.244829 30.433192 

Parametriskt test: T-test av P/EBITDA

#t-test
t.test(Psales$`P/EBITDA` ~Psales$Leader, mu=0, alt="two.sided")

    Welch Two Sample t-test

data:  Psales$`P/EBITDA` by Psales$Leader
t = 2.7283, df = 131.03, p-value = 0.007241
alternative hypothesis: true difference in means is not equal to 0
95 percent confidence interval:
 0.2704579 1.6971349
sample estimates:
mean in group 0 mean in group 1 
       2.424347        1.440550 

boxplot(Psales$`P/EBITDA` ~Psales$Leader)

Parametriskt test: Winsoriserat(5%) t-test av ‘P/Net Sales’

t.test(winsorize(Psales$`P/EBITDA`) ~Psales$Leader, mu=0, alt="two.sided")

    Welch Two Sample t-test

data:  winsorize(Psales$`P/EBITDA`) by Psales$Leader
t = 2.6033, df = 69.923, p-value = 0.01127
alternative hypothesis: true difference in means is not equal to 0
95 percent confidence interval:
 0.09484341 0.71625675
sample estimates:
mean in group 0 mean in group 1 
       1.513509        1.107959 

boxplot(winsorize(Psales$`P/EBITDA`) ~Psales$Leader)

Icke-parametriskt test: Mann-Whitney U-test

wilcox.test(Psales$`P/EBITDA`~Psales$Leader, mu=0, alt="greater", conf.int=T, conf.level=0.95, paired=F, exact=T,correct=T)

    Wilcoxon rank sum test

data:  Psales$`P/EBITDA` by Psales$Leader
W = 8421, p-value = 0.006192
alternative hypothesis: true location shift is greater than 0
95 percent confidence interval:
 0.1113046       Inf
sample estimates:
difference in location 
             0.3546282 

P/EPS

Beroende variabel: P/EPS
Oberoende Variabel: Ledare(1)

Deskriptiv statistik:

Peps <- read_excel("~/Documents/analysis/peps.xlsx")

summary(Psales$`P/EPS`)

      Min.    1st Qu.     Median       Mean    3rd Qu.       Max. 
-235.59292    0.15600    0.95901   -0.03665    2.23245   99.47433 

Parametriskt test: T-test av P/EPS

t.test(Psales$`P/EPS` ~Psales$Leader, mu=0, alt="two.sided")

    Welch Two Sample t-test

data:  Psales$`P/EPS` by Psales$Leader
t = -0.53759, df = 324.45, p-value = 0.5912
alternative hypothesis: true difference in means is not equal to 0
95 percent confidence interval:
 -3.572237  2.038921
sample estimates:
mean in group 0 mean in group 1 
     -0.1504864       0.6161719 

boxplot(Psales$`P/EPS` ~Psales$Leader)

Parametriskt test: Winsoriserat(5%) t-test av ‘P/EPS’

t.test(winsorize(Psales$`P/EPS`) ~Psales$Leader, mu=0, alt="two.sided")

    Welch Two Sample t-test

data:  winsorize(Psales$`P/EPS`) by Psales$Leader
t = 1.3229, df = 71.11, p-value = 0.1901
alternative hypothesis: true difference in means is not equal to 0
95 percent confidence interval:
 -0.1567133  0.7746386
sample estimates:
mean in group 0 mean in group 1 
      1.1625727       0.8536101 

boxplot(winsorize(Psales$`P/EPS`) ~Psales$Leader)

Icke-parametriskt test: Mann-Whitney U-test

wilcox.test(Psales$`P/EPS`~Psales$Leader, mu=0, alt="two.sided", conf.int=T, conf.level=0.95, paired=F, exact=T,correct=T)

    Wilcoxon rank sum test

data:  Psales$`P/EPS` by Psales$Leader
W = 7763, p-value = 0.1547
alternative hypothesis: true location shift is not equal to 0
95 percent confidence interval:
 -0.1222284  0.8006830
sample estimates:
difference in location 
             0.3141649