Panel A: Audit firm size and disclosure characteristics of key audit matters

Big 4

(1)

N = 352

Big 8

(2)

N = 3580

Other local audit firm

(3)

N = 1723

(1) vs. (3)

(2) vs. (3)

(1) vs.(2)

Mean

Mean

Mean

Mean difference

Mean difference

Mean difference

Kam_num

2.134

2.124

2.048

0.086**

0.076***

0.010

Length_sum

1328.821

1222.213

1131.525

197.296***

90.688***

106.608***

Length_unit

635.566

576.714

554.652

80.915***

22.063***

58.852***

Specificity1_sum

119.190

104.442

94.942

24.248***

9.500***

14.749***

Specificity1_unit

57.175

48.943

46.399

10.776***

2.544***

8.232***

Specificity2_sum

0.192

0.185

0.176

0.016***

0.009***

0.007

Specificity2_unit

0.090

0.086

0.085

0.005***

0.001

0.004***

Ind spec_sum

0.793

0.899

0.861

−0.068*

0.038**

−0.107***

Panel B: Tenure of audit firmb and disclosure characteristics of key audit matters

Short audit tenure (1)

N = 1962

Long audit tenure (2)

N = 3693

(1) vs (2)

Mean

Mean

Mean difference

Kam_num

2.069

2.118

−0.049***

Length_sum

1181.227

1211.838

−30.611**

Length_unit

573.966

573.491

0.476

Specificity1_sum

99.470

104.057

−4.587***

Specificity1_unit

47.948

49.070

−1.122**

Specificity2_sum

0.178

0.185

−0.007***

Specificity2_unit

0.085

0.087

−0.002**

Ind spec_sum

0.923

0.858

0.065***

Panel C: Industry expertise of audit firms and disclosure characteristics of key audit matters

No industry expertise (1)

N = 2598

Industry expertise (2)

N = 3066

(1) vs (2)

Mean

Mean

Mean difference

Kam_num

2.085

2.115

−0.029

Length_sum

1176.670

1221.946

−45.276***

Length_unit

566.568

579.641

−13.073***

Specificity1_sum

98.710

105.636

−6.926***

Specificity1_unit

47.277

49.866

−2.589***

Specificity2_sum

0.179

0.186

−0.007***

Specificity2_unit

0.085

0.087

−0.002***

Ind spec_sum

0.854

0.903

−0.049***