Vassar Scholarship

The paper investigates navigability with imperfect information. It shows that the properties of navigability with perfect recall are exactly those captured by Armstrong's axioms from database theory. If the assumption of perfect recall is omitted, then Armstrong's transitivity axiom is...

We develop a model of bargaining and litigation in the context of patent licensing (or any contractual setting). Following Priest and Klein (1984) we developed a model that explicitly allows for (1) multiple parties (leading to asymmetry of stakes), (2)...

The paper introduces a notion of a budget-constrained multiagent transition system that associates two financial parameters with each transition: a pre-transition minimal budget requirement and a post-transition profit. The paper proposes a new modal language for reasoning about such a...

The paper proposes a bimodal logic that describes an interplay between coalition strategies and distributed knowledge. Unlike the existing literature, the paper assumes that a strategy must be not only executable but also verifiable. That is, the strategy of a...

In this note we investigate the infringement (entry) decision for a firm facing an incumbent patent holder with uncertain patent rights. The entrant risks a dispute by entering, resulting in either a settlement (licensing) or litigation and trial. Using the...

Modal logic S5 is commonly viewed as an epistemic logic that captures the most basic properties of knowledge. Kripke proved a completeness theorem for the first-order modal logic S5 with respect to a possible worlds semantics. A multiagent version of...

Although first proposed in the database theory as properties of functional dependencies between attributes, Armstrong's axioms capture general principles of information flow by describing properties of dependencies between sets of pieces of information. This article generalizes Armstrong's axioms to a...

In June 2005, the Supreme Court made one of its least popular decisions in recent history. In Kelo v. New London, the Court missed a simple point: that local decision makers make local decisions.

This paper presents structural estimates of the probability of validity, and the probability of Type I and Type II errors by courts in patent litigation. Patents are modeled as uncertain property rights, and implications of the model are tested using...

The article investigates an influence relation between two sets of agents in a social network. It proposes a logical system that captures propositional properties of this relation valid in all threshold models of social networks with the same structure. The...

This paper merges patent citation data with data on pharmaceutical patent expirations, generic entry, and pricing to explore the effects of observable patent characteristics on off-patent and on-patnet pharmaceutical pricing. Using a sample of drug patents facing generic entry in...

The fact that a coalition has a strategy does not mean that the coalition knows what the strategy is. If the coalition knows the strategy, then such a strategy is called a know-how strategy of the coalition. The paper proposes...

The paper proposes a bimodal logic that describes an interplay between distributed knowledge modality and coalition know-how modality. Unlike other similar systems, the one proposed here assumes perfect recall by all agents. Perfect recall is captured in the system by...

The use of patent citations as a measure of patent "quality" increased dramatically in recent years. I estimate the hazard of patent citation, and find evidence of unobserved heterogeneity. Hazard estimation provides a means to separate patent quality from citation...

In this paper I present a real options model of patent litigation when patents are not perfectly enforceable. I consider both finite horizon and infinite horizon models. The theoretical results demonstrate that patent value depends not only on the underlying...

Using a sample of patents litigated between 1977 and 1997, I estimate stock market reactions to patent litigation decisions and to patent grants. I find that the resolution of uncertainty over validity and infringement is worth as much to the...

The existence of a coalition strategy to achieve a goal does not necessarily mean that the coalition has enough information to know how to follow the strategy. Neither does it mean that the coalition knows that such a strategy exists...