What law governed the substantive contract and agency questions, and what law governed the allocation of decisionmaking between judge and jury?
Holding
New York substantive law governed the contract and agency issues, while federal law governed whether those issues were for the jury.
Reasoning
Because the federal district court sat in New Jersey in a diversity case, it was required to use New Jersey choice-of-law rules. Under those rules, New York law controlled the substantive issues because the alleged compensation agreement was made and was to be performed in New York.
Erie does not determine the respective roles of judge and jury in federal court. Federal law controlled that procedural question, and under federal law the scope of an agent's apparent authority presented a factual issue for the jury. New York law reached the same result.