Professor Larry Ribstein’s latest scholarship on the scope of fiduciary duties and an analysis of what types of relationships warrant the exalted status that comes with corresponding heightened obligations, is the topic of his post here, which describes this work by one of the nation’s leading scholars in this field as follows:

The fiduciary duty is appropriately construed as one of unselfishness, as distinguished from lesser duties of care, good faith and fair dealing, and to refrain from misappropriation. The fiduciary duty of unselfishness is appropriate only for a limited class of agency relationships in which the principal delegates open-ended power to the agent, and not for those who may exercise lesser power over the property of others, including co-investors, advisors, professionals, and those in confidential relationships. More broadly applying fiduciary duties could unnecessarily constrain parties from self-protection in contractual relationships, impose excessive litigation costs, provide an unsuitable basis for contracting, and impede developing fiduciary norms of behavior. This analysis of fiduciary duties helps address current issues, including those regarding the duties of brokers, dealers, and investment and mutual fund advisors. In short, fencing fiduciary duties protects both fiduciary and non-fiduciary relationships and enables parties to contract for the precise level of protection that is appropriate to the services they are purchasing. 

The paper develops, updates and applies ideas from my earlier paper, Are Partners Fiduciaries?