Determinants of audit fees: Evidence from Poland

Final version of the linear regression model

Description of the variables used in the study

Variables	Expected impact	Description of the variable
lnAuditFee	N/A	Natural logarithm of the amount of audit fees for conducting a mandatory audit of an entity's financial statement in the period covered by the statement (including fees for reviews of financial statements)
lnTOTALASSETS	+	Natural logarithm of the total assets
BIG4	+	Discrete variable coded as 1 if a company's auditor is Deloitte, EY, KPMG or PwC, and 0 in other cases
MERGE	+	Discrete variable coded as 1 if there was a merger or acquisition of entities forming a corporate group during a financial year and 0 in other cases
LEVERAGE	+	Company's debt to total assets ratio
Complexity	+	A company's total short- and long-term receivables and inventories
Foreign	+	The ratio of the number of foreign companies in a corporate group to the number of all companies forming the corporate group
lnSales2018	+	Natural logarithm of sales volume in 2018

Basic characteristics of the variables (non-logarithmic values for the variables AuditFee, TOTALASSETS and Sales2018)

Variable	Mean	Standard deviation	Min	Max
AuditFee	598,957	1,028,801	16,000	5,881,000
TOTALASSETS	5,478,254,619	12,263,775,906	34,686,420	75,905,000,000
BIG4	0.6306306	0.4848229	0	1
MERGE	0.2432432	0.4309865	0	1
LEVERAGE	0.1638752	0.1459938	0	1
Complexity	0.3086383	0.2124534	0.0061615	0.8692479
Foreign	0.2534987	0.2651958	0	0.9545455
Sales2018	4,488,839,727	11,919,499,823	17,486,560	109,706,000,000

Correlation between variables

	lnTOTALASSETS	BIG4	MERGE	LEVERAGE	Complexity	Foreign	lnSales2018
lnTOTALASSETS	1
BIG4	0.4497*	1
MERGE	0.1461		1
LEVERAGE	0.1153	0.3038*	0.1318	1
Complexity	−0.1528	−0.2342*	−0.097	0.3808*	1
Foreign	−0.0311	0.0733	−0.0311	0.118	0.0544	1
lnSales2018	0.8593*	0.3053*	0.1612	0.2627*	0.0893	−0.1229	1