So you're saying that if the tax were lower, people would fire their accountants and pay more taxes out of the goodness of their hearts? A sense of fairness?
Typical assumption is that the peak of Laffer Curve is somewhere between 30% and 70%.
Despite large cuts in corporate income tax and a reduction in consumption tax coupled with temporary increased spending, Canada's debt to GDP ratio is where it was before the '08 crash. The debt increased about 50% during this time, but so did the GDP. Companies stayed in Canada/came to Canada and with growth came more tax revenue. The fear was that the books would never get near balanced again with drastically reduced tax rates, but 2014/2015 was roughly balanced. (Arguably about -$3 billion for the whole year)