Committed labour costs required prudence review, not hindsight benchmarking.
The appellants challenged a regulatory decision reducing a power generator's proposed revenue requirements for nuclear compensation costs during a forward test period.
The Court of Appeal held that future compensation costs mandated by existing collective agreements were committed costs, not forecast costs that could simply be managed downward.
The Board acted unreasonably by relying on hindsight and current benchmarking information unavailable when the collective agreements were made, and by failing to conduct a prudence review based on what was known or ought to have been known at the time of the commitments.
The matter was remitted to the Board for rehearing in accordance with those principles.
Power Workers' Union, Canadian Union of Public Employees, Local 1000 v. Ontario Energy Board, 2013 ONCA 359