The parliamentary budget officer estimates the Liberals' increase to the capital gains inclusion rate will bring in $17.4 billion in revenue over five years.
That's two billion dollars less than the federal government projected in its spring budget.
The Liberal government proposed making two-thirds rather than one-half of capital gains — the profit made on the sale of assets — taxable.
The proposal was met with pushback from business groups as well as physicians who expect to be affected by the change.
Prime Minister Justin Trudeau has defended what is effectively a tax increase, arguing that it is about delivering generational fairness to young people who need the government to spend more on things like housing.
The increase to the inclusion rate came into effect on June 25, although legislation has yet to pass Parliament.