We investigate how liability rules and property rules protect intellectual property. Infringement might not be deterred under any of the enforcement regimes available. However, counterintuitively, a credible threat of infringement can actually benefit the patentholder. We compare the two doctrines of damages, lost profit (lost royalty) and unjust enrichment, and argue that unjust enrichment pro...

This paper studies royalty negotiations between a patent holder and a downstream firm selling a product which is more valuable if it includes a feature covered by the patent. Royalties are negotiated in the shadow of patent litigation, which will determine whether or not the patent is valid and infringed. If the two firms negotiate after the downstream firm has already designed its product to i...

Believability requires video game characters to consider their actions within the context of social norms. Social norms involve a broad range of behavioral defaults, obligations, and injunctions unrelated to strictly causal reasoning. Defeasible reasoning involves rationally compelling but deductively invalid arguments, such as reasoning with rules that allow exceptions. This paper investigates...