26 Wash. 2d 282, 173 P.2d 652 (Wash. 1946)
Olwell v. Nye & Nissen Co.
May the owner of a chattel, wrongfully used by another without consent, waive the tort of conversion and recover in restitution the value of the benefit to the wrongdoer (measured by savings or gains from the use), even when the owner's own loss or the rental value is less or difficult to quantify?
A plaintiff whose property has been wrongfully used may elect to waive the tort and sue in quasi-contract (assumpsit) for restitution of the unjust enrichment realized by the wrongdoer. In such an action, the proper measure is the value of the benefit to the defendant—i.e., the gains or cost savings attributable to the wrongful use—rather than the plaintiff's loss, market rental value, or the property's sale price. Willful trespassers and converters are not permitted to retain profits or savings derived from their wrongs.
Yes. The plaintiff could recover, in restitution, the value of the benefit obtained by the defendant from its unauthorized use of the machine. The appropriate measure was the value-to-the-defendant of that use—here, the labor cost savings—calculated at $10 per day for approximately 156 uses, totaling $1,560.
The case is frequently taught to illustrate: (1) election of remedies—permitting a plaintiff to waive tort damages and seek quasi-contract recovery; (2) the core restitution principle that the measure may be the defendant's gain rather than the plaintiff's loss; and (3) the policy of deterring willful trespass and conversion by denying wrongdoers any net benefit from their misconduct. It is a canonical example of the value-to-the-defendant measure in unjust enrichment and a foundational authority in Remedies and Restitution courses.