This study investigates whether large Australian companies use their political power to lower their effective tax rates (ETRs) over and above their political costs. It also tests whether there is an industry effect on ETRs for the mining and financial industries in Australia. This study expands the current research into the effect of political power on ETRs by incorporating other tax rate theories. Using 402 mature Australian public companies over a 13-year period the study applies three separate tests to profitable companies.
Firstly, we employ panel data analysis to examine changes in the ETR of 55 profitable companies over the 2000-2012 periods. Secondly, we use cross-sectional analysis to ascertain the relationship that the effect can be seen over a long period by using panel data testing methodology between company size and ETR for profitable companies on a year-by-year basis. Finally, we assess various tax-rate theories by examining the ETR paid by the profitable public companies in 2012.
Out findings from this study provide evidence that there is a consistent negative relationship between company size and ETRs. We suggest, that further research incorporating the use of qualitative data would be needed to counter the effect of political costs on individual companies and industries.