Normative Systems: Semantics and Proof Theory Silvano Colombo Tosatto SnT, University of Luxembourg Luxembourg Guido Boella University of Turin Italy Leendert van der Torre University of Luxembourg Luxembourg Serena Villata INRIA France

Traditional economic decision theory proposes that people behave in certain ways when faced with a well-formulated set of alternatives and information. It is a normative theory; it suggests that people should act according to certain decision rules, but not that they will necessarily do so in reality. The standard assumption is that a person has a utility function over all possible outcomes, wh...

The paper discusses the sense in which the changes undergone by normative economics in the 20 century can be said to be progressive. A simple criterion is proposed to decide whether a sequence of normative theories is progressive. This criterion is put to use on the historical transition from the new welfare economics to social choice theory. The paper reconstructs this classic case, and eventu...

Intelligent Tutoring Systems (ITSs) are a technology for supporting teachers. They are intelligent software programs equipped with subject knowledge, a student model, and teaching ability. This paper reports on the outcome of PhD research aimed at making ITSs more robust and effective, by applying normative theories such as Bayesian probability theory and decision theory, to the design and impl...

In this paper we use recursive modelling to formalize sanction-based obligations in a qualitative game theory. In particular, we formalize an agent who attributes mental attitudes such as goals and desires to the normative system which creates and enforces its obligations. The wishes (goals, desires) of the normative system are the commands (obligations) of the agent. Since the agent is able to...

Law often grows from social norms that create order. Many social norms change behavior by imposing obligations on people. I model the evolution of effective consensus obligations. Some consensus obligations succeed on their own and others require the backing of state law. This paper analyzes the causes of normative failure and provides a diagnostic tool for legal intervention. Characterizing fa...

A scientific reasoning system makes decisions using objective evidence in the form of inde­ pendent experimental trials, propositional ax­ ioms, and constraints on the probabilities of events. As a first step towards this goal, we propose a system that derives probability in­ tervals from objective evidence in those forms. Our reasoning system can manage uncertainty about data and rules in a ru...

Rationality is one of the most over-used words in economics. Behaviour can be rational, or irrational. So can decisions, preferences, beliefs, expectations, decision procedures, and knowledge. There may also be bounded rationality. And recent work in game theory has considered strategies and beliefs or expectations that are “rationalizable”. Here I propose to assess how economists use and mis-u...

In this paper we are interested in developing goal-based normative agent architectures. We ask ourselves the question what a normative goal is. To answer this question we introduce a qualitative normative decision theory based on belief (B) and obligation (O) rules. We show that every agent which makes optimal decisions – which we call a BO rational agent – acts as if it is maximizing the set o...