Variable

Coeff.

Std. error

z

P value

Significance

const

−55.0557

8.88217

−6.198

5.70e−10

***

demand

0.00407

0.00068

6.006

1.90e−09

***

demand_lag2

−6.83276e−05

7.03114e−06

−9.718

2.53e−22

***

demand_lag5

2.48008e−05

4.19369e−06

5.914

3.34e−09

***

demand^2

−1.03906e−07

1.70983e−08

−6.077

1.22e−09

***

demand^3

9.09128e−13

1.42697e−13

6.371

1.88e−10

***