Since a 50% increase in the capital gains taxation  may be in the cards for the Liberal budget, while Bernier wants to drop it 100%, let's discuss that.  

The 50% exemption for capital gains income promotes investment in growth companies that are riskier than dividend stocks, bond or GIC investments.  Significantly reduce that and you are playing with fire.

However, eliminate capital gains taxes altogether and you will allow rich investors to pay no income tax at all.  It could juice capital investment and the GDP, but at the expense of equality and social cohesion.