By international standards, Australia’s business tax system combines a high company tax rate of 30 per cent with low taxation of domestic investors through dividend imputation. This prioritising of domestic investors over foreign investors is at odds with the evidence in this paper that the marginal investor is foreign. Better aligning Australia’s business tax system with international practice would encourage business investment, reduce tax avoidance and reduce the riskiness of national income. This paper assesses the evidence on the size of these three effects and models the consumer benefits of better aligning the Australian business tax system with international practice.