475 firms: Equation (4)

α

β

γ

Constrained OLS*

Estimated coefficients

0.30856

0.86762

0.132377

t-statistic

(0.320)

(18.866)

(2.878)

standard error

0.964

0.046

0.046

Constrained OLS*, with the constant suppressed

Estimated coefficients

NC

0.87705

0.12295

t-statistic

(24.857)

(3.485)

standard error

0.035

0.035