Good faith and fiduciary duty

Mariana Pargendler posted in 2008 in SSRN a paper on good faith and fiduciary duties. She discusses the issue in the context of american law although the discussion is much older – and maybe deeper – in continental Europe. Germans authors have written extensively on the subject.

I distinguish good faith and fiduciary duties by showing that good faith provides a framework for tailored gap-filling by enabling courts to provide the term most suitable to the agreement in question, while fiduciary duties are untailored defaults that provide the regime that most parties in a fiduciary category would have wanted. This claim has not yet been advanced in the literature on good faith and fiduciary duties… While a tailored provision aims to supply precisely the terms the parties would have contracted for, an untailored provision supplies the parties with a “single, off-the-rack standard that in some sense represents what the majority of contracting parties would want.”13 Here I argue that good faith and fiduciary duties are tailored and untailored standards, respectively.1

It sounds like the distinction, usual in Germany, between ergänzende Vertragsauslegung and Vertragsergänzung (How generous german professors are can be seen when you make a search in Google for both legal terms and then you compare the results with a search of fiduciary duties and good faith in contract interpretation). She cites Easterbrook/Fischel

“When transactions costs reach a particularly high level, some persons start calling some contractual relations ‘fiduciary… In this context, incomplete contract situations characterized by unusually high costs of specification and monitoring may give rise to fiduciary duties. On the contrary, good faith is the canon of interpretation for ordinary contracts…

But she finds that this explanation, being basically correct,

it does not specify what distinguishes good faith and fiduciary duties as gap-filling methods

Yes it does. A fiduciary duty assumes a relationship with an unspecified number of occasions where the agent has to exert discretion and the contract (the agent's contract with the principal) does not provide for guidance but in a very general way (“maximize the value of the company”; “maximize the welfare of the child… “the interest of the company above all”). As Easterbrook and Fischel also say and Pargendler quotes

“when one party hires the other’s knowledge and expertise, there is not much they can write down.”

Good faith as a gap-filling tool refers to an specific obligation in the framework of a contract. The promisor has to fulfill the contract and has to do all that is necessary to satisfy the contractual interest of the promisee within its promise even if it is not precisely foreseen in the contract. Good faith, as in art. 1258 spanish Civil code is an order to fill a gap in a coherent way with the whole contract. As Pangendler says

“Good faith is thus no more than a residual method of gap-filling, one that fill gaps based on hints provided by the contract’s express terms

And of course, nothing to do with good faith in a subjective sense as opposed to acting on purpose to harm someone or as meaning a mistaken understanding or false knowledge and, also, different to the duty to perform a contract in good faith (art. 57 Code of Commerce, for example).