Number of observations:441

Outcome measure

Income measure

US Firms

Management Practices

competition

ownership

Firm age

Human Resources

X_1a

X_1b

managers’ degree

Employees’ degree

hours

Payment

Minimum

1.61

0

−3.90

0

1.39

0

0.69

30

4.55

Maximum

4.83

3

0.70

1

5.34

40

4.55

80

8.04

Mean

3.32

2.47

−1.70

-

3.57

1.90

3.15

48.03

6.26

Std. Deviation

0.72

0.69

0.73

-

0.80

4.43

0.81

5.70

0.67

UK Firms

Management Practices

X_1a

X_1b

ownership

Firm age

managers’ degree

Employees’ degree

hours

Payment

Minimum

1.06

0

−2.72

0

1.10

0

0.69

35

-

Maximum

4.86

3

0.25

1

5.50

15

4.17

60

-

Mean

3.04

2.25

−1.02

-

3.31

0.73

2.32

44.20

-

Std. Deviation

0.81

0.97

0.59

-

1.04

2.02

0.81

6.40

-