The corporate tax rate isn't 15% as you stated.  That's just the federal take.  Provinces have their own tax rate that raises the corporate rate to 25% at a minimum.  But that's just the income tax.  Corporations also pay muni taxes, employer health tax, employment tax (at 140% of your EI rate) CPP tax, and a few others as well.   The answer to your question though is whether we want investment in Canada or whether we want to see investment go elsewhere?  Remember that investment creates jobs and jobs mean governments receive revenue from citizens.  As for the current tax system...I believe the top 20% of tax payers pay over 50% of income taxes.  That isn't fair in my view, (but it IS progressive) but I accept it as necessary to call myself Canadian.  As a final thought...it seems to me that the people paying the least tax are the ones who consume the greatest government benefits.  That isn't fair either is it?