stillwater wrote:anyone know when to use Arbitrary and Capricious test versus when to use Chevron?
Depends on which arb & cap review you mean. Chevron
deference is for agency interpretations of law (in situations where the agency is acting with force of law).
"Arbitrary and capricious" is used in several ways. "Arbitrary and capricious" is the standard of review for agency determinations of fact in informal proceedings. This standard is the same as "substantial evidence" review of findings of fact in formal proceedings, see ADAPSO v. Board of Governors of the Fed. Reserve
Any agency action (even procedural action that is not a determination of law or fact) is also subject to review of whether it is arbitrary and capricious (this is so-called "hard look" review). So an agency action that includes a determination of law reviewed under Chevron
deference might also be subject to "hard look" review. Hard look review of agency action is basically a reasonableness inquiry (see Overton Park
or Motor Vehicle Manufacturers Assoc. v. State Farm