The reduction of corporate income tax to the current rate of 15% was extremely important, being one of the measures that made it possible for Canada to maintain its level of economic activity. Certainly, the ability of businesses to make investments and hire employees does not depend solely on the tax rate, but it does play a significant role. The global context likely played a role as well. Global demand was lacking. Lower corporate tax rates are clearly conducive to investment and job creation. To put it in economists' terms, these tax reductions tend to be self-financing.
On October 28th, 2014. See this statement in context.