It's a question of how the tax estimate system can be most conducive to economic growth. In recent years in Canada we've taken the approach that the tax system can best facilitate economic growth, investment, and advancements in productivity by providing an efficient tax system that is broadly neutral and by lowering tax rates, to the extent we can afford to do so. This approach was adopted by many countries about two decades ago. There were various tax reforms around the world. Canada was part of that movement at the time; the United States was as well. Since then, the United States has tended to move back towards a system with more targeted incentives. In Canada, successive governments have remained relatively consistent in the approach.
On October 17th, 2006. See this statement in context.