I am guilty of one book on the general subject, two articles on Canadian law (here and here) and innumerable posts on the subject, and I have a couple of projects in the pipeline (though once they are concluded, I will try to move onto other things!). But the reason the standard of review keeps coming up is that vast swathes of the law remain unresolved and contestable.
Hence David Mullan's mammoth "Unresolved Issues on Standard of Review in Canadian Judicial Review of Administrative Action - the Top Fifteen!" (2013), 42 Advocates' Quarterly 1-85. As the title and exclamation mark suggest, Professor Mullan could have gone on at even greater length. Five years after its reformulation of judicial review doctrine in Dunsmuir, the Supreme Court of Canada still has a lot of work to do.
In a hot-off-the-press article, "Can There Be Too Much Context in Administrative Law? Setting the Standard of Review in Canadian Administrative Law", Andrew Green takes the view that the Court is on the right track. Applying an institutionalist approach to the standard of review issue, he concludes:
The presumption of reasonableness potentially reduces the uncertainty and cost of undertaking judicial review. This reduction in uncertainty and cost should, all other things being equal, improve decision-‐making by executive decision-‐makers, potential challengers of decisions and the legislature. They should all be better able to determine the probable stringency of review (at least broadly) and make choices in the shadow of this review....The shift to categories in Dunsmuir should also make it easier for lower courts to determine the standard of review, which should reduce the number of mistakes. Further, it should increase the ease with which higher level courts can monitor judicial review by lower courts. Such monitoring should also reduce the overall number of mistakes in the assigning of the standard of review as well as any manipulation of the choice of standards by lower courts (p. 48, 50).Notwithstanding Green's institutional analysis (much of which is uncontestable) I remain unconvinced of the promise of a categorical approach for two reasons set out in the articles referenced above.
First, where choices between categories have to be made, judges inevitably have to rely on some other factors (such as the factors from the pragmatic and functional analysis). Yet they may do so without identifying the relevant factors or giving reasons for their reliance on the factors, thus (a) opening the door to manipulation of the standard, which is more difficult to observe in the absence of reasons and (b) creating confusion for litigants on all sides. And if no reasons are given, error detection might be difficult (giving confused litigants less of an incentive to appeal) such that the benefits and costs of a categorical approach may be a wash (note the emphases: this point requires some reflection).
These difficulties might be overcome by the adoption of an automatic reasonableness standard. Indeed, Green sounds a cautious note about the continued existence of categories that attract correctness review. Yet this leads to the second reason for doubt. In determining the "degree" of deference or the intensity with which reasonableness is applied, courts will inevitably have regard to external factors. If these are left unstated, issues (a) and (b) recur. And there is an additional issue. Requiring judges to focus on context has an educative function. It forces them to confront the features of the regulatory regime and their relative institutional competence. A rule that the judge is to proceed automatically to the analysis of the reasonableness of a decision may ultimately undermine deference.
This is not a criticism of Green's paper. He takes the Court at its word in asserting that reasonableness is not a variable standard, which is perfectly proper for his purposes, but the Court's assertion is dubious. In the most sophisticated judicial attempts to define reasonableness, factors such as the scope of power delegated and the nature of the question at issue have been prominent.
I should also note that Mullan points out that an automatic reasonableness standard might raise further problems, including constitutional ones. As long as a core minimum of review is retained, those constitutional problems may be overcome, but that very much depends on what the core minimum looks like.
In summary, Canadian administrative law scholars are not done with the standard of review just yet!