X1 X2

X1

Left-skewed covariate

X2

Right- skewed covariate

D1 binary

(skewness, kurtosis)

Mean

SD

(S, K) Coefficient

SE

Power

Mean

SD

(S, K) Coefficient

SE

Power

Coefficient SE

SE

Power

70

8

β1 = 0.05

160

25

β2 = 0.02

β2 = 0.83

Correlation of (X1, X2) = 0.0

(0.0 0.0, 0.0 0.0)

70.0

8.0

(0.0, 0.0) 0.051

0.015

0.943

160.1

25.0

(0.0, 0.0) 0.020

0.005

0.997

0.846

0.233

0.947

(−0.5 0.5, 0.0 0.0)

70.0

8.0

(−0.5, 0.5) 0.051

0.015

0.930

160.1

25.0

(0.0, 0.0) 0.020

0.005

0.995

0.846

0.233

0.945

(−1.0 1.0, 0.0 0.0)

70.0

8.0

(−1.0, 1.0) 0.051

0.016

0.919

160.1

25.0

(0.0, 0.0) 0.020

0.005

0.996

0.843

0.233

0.942

(0.0 0.0, 0.4 0.3)

70.0

8.0

(0.0, 0.0) 0.051

0.015

0.945

160.0

25.0

(0.4, 0.3) 0.020

0.005

0.996

0.846

0.234

0.947

(0.0 0.0, 0.8 0.6)

70.0

8.0

(0.0, 0.0) 0.051

0.015

0.938

160.0

25.0

(0.8, 0.6) 0.020

0.005

0.997

0.843

0.234

0.950

(−0.5 0.5, 0.4 0.3)

70.0

8.0

(−0.5, 0.5) 0.051

0.015

0.929

160.0

25.0

(0.4, 0.3) 0.020

0.005

0.996

0.845

0.234

0.949

(−1.0 1.0, 0.8 0.6)

70.0

8.0

(−1.0, 1.0) 0.051

0.016

0.922

160.0

25.0

(0.8, 0.6) 0.020

0.004

0.999

0.841

0.234

0.945

Correlation of (X1, X2) = 0.3

(0.0, 0.0) (0.0, 0.0)

70.0

8.0

(0.0, 0.0) 0.051

0.015

0.919

160.0

25.0

(0.0, 0.0) 0.020

0.005

0.984

0.852

0.234

0.957

(−0.5, 0.5) (0.0, 0.0)

70.0

8.0

(−0.5, 0.5) 0.051

0.016

0.903

160.0

25.0

(0.0, 0.0) 0.020

0.005

0.988

0.852

0.233

0.960

(−1.0, 1.0) (0.0, 0.0)

70.0

8.0

(−1.0, 1.0) 0.052

0.017

0.880

160.0

25.0

(0.0, 0.0) 0.020

0.005

0.987

0.853

0.233

0.965

(0.0, 0.0) (0.4, 0.3)

70.0

8.0

(0.0, 0.0) 0.051

0.015

0.920

160.0

25.0

(0.4, 0.3) 0.020

0.005

0.990

0.850

0.234

0.953

(0.0, 0.0) (0.8, 0.6)

70.0

8.0

(0.0, 0.0) 0.051

0.015

0.920

160.0

25.0

(0.8, 0.6) 0.020

0.005

0.991

0.849

0.235

0.952

(−0.5, 0.5) (0.4, 0.3)

70.0

8.0

(−0.5, 0.5) 0.051

0.016

0.902

160.0

25.0

(0.4, 0.3) 0.020

0.005

0.992

0.852

0.234

0.954

(−1.0, 1.0) (0.8, 0.6)

70.0

8.0

(−1.0, 1.0) 0.052

0.017

0.879

160.0

25.0

(0.8, 0.6) 0.020

0.005

0.991

0.850

0.234

0.957

Correlation of (X1, X2) = 0.6

(0.0, 0.0) (0.0, 0.0)

70.0

8.0

(0.0, 0.0) 0.051

0.018

0.811

160.0

25.0

(0.0, 0.0) 0.021

0.006

0.949

0.853

0.235

0.962

(−0.5, 0.5) (0.0, 0.0)

70.0

8.0

(−0.5, 0.5) 0.051

0.019

0.772

160.0

25.0

(0.0, 0.0) 0.020

0.006

0.945

0.851

0.234

0.960

(−1.0, 1.0) (0.0, 0.0)

70.0

8.0

(−1.0, 1.0) 0.052

0.020

0.753

160.0

25.0

(0.0, 0.0) 0.020

0.006

0.951

0.853

0.233

0.966

(0.0, 0.0) (0.4, 0.3)

70.0

8.0

(0.0, 0.0) 0.051

0.018

0.815

160.0

25.0

(0.4, 0.3) 0.020

0.006

0.959

0.852

0.235

0.946

(0.0, 0.0) (0.8, 0.6)

70.0

8.0

(0.0, 0.0) 0.051

0.018

0.819

160.0

25.0

(0.8, 0.6) 0.020

0.005

0.970

0.850

0.236

0.947

(−0.5, 0.5) (0.4, 0.3)

70.0

8.0

(−0.5, 0.5) 0.051

0.019

0.785

160.0

25.0

(0.4, 0.3) 0.020

0.006

0.959

0.853

0.235

0.956

(−1.0, 1.0) (0.8, 0.6)

70.0

8.0

(−1.0, 1.0) 0.052

0.020

0.757

160.0

25.0

(0.8, 0.6) 0.020

0.005

0.979

0.850

0.234

0.966