Tuesday's letters: Wrong to focus on Grey Cup's impact

Why do our governments keep using the wrong metrics to rationalize investment decisions in tourism and sporting events?
While the Grey Cup may have an economic impact of $100 million, will the economic benefits actually exceed the costs? Economic-impact assessments treat both benefits and costs as impacts. So, if it costs $20 million to host an event that brings in $10 million in visitor spending, you get $30 million in impacts.
Would a businessperson invest $20 million in a machine that could s