First Expansion

Second Expansion

Third Expansion

Before

C

21.88

43.43

42.32

T

22.09

44.94

43.91

${\beta }_2$

Std. Error

0.20*

1.52***

1.59***

(0.11)

(0.17)

(0.17)

After

C

21.28

44.71

42.81

T

21.00

44.35

43.47

${\beta }_2\text{+}{\beta }_3$

Std. Error

−0.28***

−0.36**

0.66***

(0.09)

(0.17)

(0.15)

${\beta }_3$

Std. Error

−0.49***

−1.88***

−0.93***

(0.14)

(0.25)

(0.22)

R²

0.28

0.34

0.39