In a mammoth recent paper on Chevron deference, Gary Lawson and Stephen Kam trace the origins of the doctrine: Making Law out of Nothing at All (2013), 65 Admin Law Review 1 (draft). The paper is ably reviewed on Jotwell by Linda Jellum.
What I found most striking, in view of Canadian courts' desire to embrace Chevron deference, is the narrative Lawson and Kam set out. Before Chevron, much turned on the distinction between interpreting and applying law. Interpretation was a matter for courts; application for administrative decision-makers. But these were presumptions, rebuttable by reference to a "mélange of factors, with no clear metric for determining how much or when those factors weigh in the balance".
This is eerily similar to the framework established by the Supreme Court of Canada in Dunsmuir v. New Brunswick. In Lawson and Kam's telling, American courts were then pushed towards the beguiling simplicity of Chevron. Yet, subsequently Chevron itself has been modified to ensure that courts take into account a range of contextual factors in calibrating the appropriate amount of deference (though this has not pleased everybody). The Americans went from law/fact to rebuttable presumptions to Chevron to context.
Is this not a cautionary tale for Canadian courts? A "two-step" approach, which relies on "clarity" and "ambiguity" seems as if it would simplify an approach based on rebuttable presumptions (as it must have seemed to American judges in the 1980s). Appearances can be deceptive, however. From the American experience we can perhaps deduce that adopting Chevron would simply lead to a further set of problems. Ironically, if Canada were eventually to follow the American lead in focusing on context, the result would be something like the pragmatic and functional analysis abandoned in Dunsmuir.
Finally, as Lawson and Kam remind us, Chevron's simplicity is only skin deep: "To this day, we still do not have consensus on what it means for the meaning of a statute to be 'clear'". Chevron may just be jurisdictional error on steroids.