Reasoned decision-making as a condition precedent to deference is an increasingly attractive proposition in Canada, where affidavits and agency litigating positions can be used to place a decision-maker's thumb on the interpretive scales.There is an epistemic argument for judicial deference to the decisions of administrative agencies and legislatures: courts do not have easy access to relevant information, and they should defer to those who do. People who are steeped in technical issues, and alert to the importance of those issues, might well be inclined to embrace judicial modesty. In administrative law, then-Professor Stephen Breyer pioneered the view that judge-made doctrines reflect unarticulated assumptions about regulatory policy, and he urged that such doctrines could not be evaluated without a sense of the underlying substance and the likely human consequences. In light of the complexity of the substance, Breyer argued for a degree of modesty. On the Supreme Court, Justice Breyer has often embraced judicial modesty as well, emphasizing the importance and relevance of complex judgments of fact (sometimes with the aid of what we might call "the Breyer Appendix"). The principal qualification is his insistence on reasoned decision making, which he appears to regard as a quid pro quo for deference, as an aspect of the rule of law, and as an indispensable check on arbitrariness.
To borrow from Sunstein:
The most important point here is that an agency may not defend its policy simply by asserting its preference. It has to offer reasons. To be sure, there is a risk that a judicial demand for reasoned decision making will serve, in practice, as a judicial demand for reasons with which judges agree...Nonetheless, a requirement of reason-giving can be seen as an effort to ensure that technical expertise is in fact being applied...As Sunstein suggests, the presence of a reasoned decision may be a good proxy for the application of administrative expertise. It is interesting that the recent decline in importance of relative expertise in Canadian doctrine has coincided with the decline in importance of reasoned decision-making.