The parties’ contract contained a choice of law clause choosing New York law. Under New York law, prejudgment interest is to be awarded on any contract claim regardless of whether the damages are fixed or reasonably calculable, and interest is awarded at 9%, rather than at 10% as in California. Under Restatement (Second) of Conflicts of Law, section 207, if the choice of law clause is generally enforceable, the law of the chosen state governs the measure of recovery for breach of contract, including whether prejudgment interest is awardable and if so at what rate. This decision finds the choice of New York clause enforceable, adopts section 207, and applies New York law in upholding the prejudgment interest awarded in this case. However, a procedural provision of New York law requiring the judgment to recite the date on which interest began to accrue does not govern this case since procedural matters are governed by the forum’s law even when a different jurisdiction’s law governs the substantive rights of the parties.