Behavioural decisions & welfare

If decision-makers (DMs) do not always do what is in their best interest, what do choices reveal about welfare? This paper shows how observed choices can reveal whether the DM is acting in her own best interest. We study a framework that relaxes rationality in a way that is common across a variety of seemingly disconnected positive behavioral models and admits the standard rational choice model as a special case. We model a behavioral DM (boundedly rational) who, in contrast to a standard DM (rational), does not fully internalize all the consequences of her own actions on herself. We provide an axiomatic characterization of choice correspondences consistent with behavioral and standard DMs, propose a choice experiment to infer the divergence between choice and welfare, state an existence result for incomplete preferences and show that the choices of behavioral DMs are, typically, sub-optimal

Behavioural decisions & policy

We study the public policy implications of a model in which agents do not fully internalize all the conscequences of their actions. Such a model uni…es seemingly disconected models with behavioral agents. We evaluate the scope of paternalistic and libertarian-parternalistic policies in the light of our model, and propose an alternative type of approach, called soft-libertarian, which guides the decision makers in the internalization of all the conscequences of their actions. Psychotherapy is one example of a soft-libertarian policy. Moreover, we show that in our behavioral framework, policies that increase the set of opportunities or provide more information to the agent may not longer be individual welfare improving

Behavioural Decisions and Welfare

What are the normative implications of behavioral economics? We study a model where the decisions a person makes, consciously or unconsciously, affect her psychological state (reference point, beliefs, expectations, self-image) which, in turn, impacts on her ranking over available decisions in the first place. We distinguish between standard decisions where the decision-maker internalizes the feedback from her actions to her psychological state, and behavioural decisions where the psychological state is taken as given (although a decision outcome requires that action and psychological state are mutually consistent). In a behavioural decision, the individual imposes an externality on herself. We provide an axiomatic characterization of behavioral decisions. We show that the testable implications of behavioral and standard decisions are different and the outcomes of the two decision problems are, typically, distinguishable. We discuss the consequences for public policy of our formal analysis and over normative grounds for subsidized psychological therapiesBehavioural Decisions; Indistinguishabilty; revealed preferences; normative preferences; welfare; paternalism; autonomy; existence

Objective and Subjective Rationality in a Multiple Prior Model

A decision maker is characterized by two binary relations. The first reflects decisions that are rational in an “objective” sense: the decision maker can convince others that she is right in making them. The second relation models decisions that are rational in a “subjective” sense: the decision maker cannot be convinced that she is wrong in making them. We impose axioms on these relations that allow a joint representation by a single set of prior probabilities. It is “objectively rational” to choose f in the presence of g if and only if the expected utility of f is at least as high as that of g given each and every prior in the set. It is “subjectively rational” to choose f rather than g if and only if the minimal expected utility of f (relative to all priors in the set) is at least as high as that of g.Rationality, Multiple Priors.

von Neumann-Morgenstern and Savage Theorems for Causal Decision Making

Causal thinking and decision making under uncertainty are fundamental aspects of intelligent reasoning. Decision making under uncertainty has been well studied when information is considered at the associative (probabilistic) level. The classical Theorems of von Neumann-Morgenstern and Savage provide a formal criterion for rational choice using purely associative information. Causal inference often yields uncertainty about the exact causal structure, so we consider what kinds of decisions are possible in those conditions. In this work, we consider decision problems in which available actions and consequences are causally connected. After recalling a previous causal decision making result, which relies on a known causal model, we consider the case in which the causal mechanism that controls some environment is unknown to a rational decision maker. In this setting we state and prove a causal version of Savage's Theorem, which we then use to develop a notion of causal games with its respective causal Nash equilibrium. These results highlight the importance of causal models in decision making and the variety of potential applications.Comment: Submitted to Journal of Causal Inferenc

Flexibility of Choice Versus Reduction of Ambiguity

This paper explores the problem of a social planner willing to improve the welfare of individuals who are unable to compare all available alternatives. The optimal decision trades off the individuals' desire for flexibility versus their aversion towards ambiguous choice situations. We introduce an axiom system that formalizes this idea. Our main result characterizes the preference maximizing opportunity set. It is a maximal set that consists of mutually comparable alternatives. It also has the property that it maximizes the sum of the distances between its ordered elements for some appropriate metric imposed on the set of possible choices.Incomplete preferences, ambiguity, ?exibility of choice, opportunity sets, uncertainty

Flexibility of Choice versus Reduction of Ambiguity

This paper explores the problem of a social planner willing to improve the welfare of individuals who are unable to compare all available alternatives. The optimal decision trades off the individuals' desire for flexibility versus their aversion towards ambiguous choice situations. We introduce an axiom system that formalizes this idea. Our main result characterizes the preference maximizing opportunity set. It is a maximal set that consists of mutually comparable alternatives. It also has the property that it maximizes the sum of the distances between its ordered elements for some appropriate metric imposed on the set of possible choices.

Behavioral Decisions and Policy

We study the public policy implications of a model in which agents do not fully internalize all the conscequences of their actions. Such a model uni es seemingly disconected models with behavioral agents. We evaluate the scope of paternalistic and libertarian-parternalistic policies in the light of our model, and propose an alternative type of approach, called soft-libertarian, which guides the decision makers in the internalization of all the conscequences of their ac- tions. Psychotherapy is one example of a soft-libertarian policy. Moreover, we show that in our behavioral framework, policies that increase the set of oppor- tunities or provide more information to the agent may not longer be individual welfare improving.Behavioral Decisions;Revealed Preferences;Normative Preferences;Paternalism;Soft-Libertarian;Autonomy;Psychotherapy

Decisions with endogenous frames

We develop a model of decision-making with endogenous frames and contrast the normative implications of our model to those of choice theoretic models in which observed choices are determined by exogenous frames or ancillary conditions. We argue that, frames, though they may be taken as given by the decision-maker at the point when choices are made, matter for both welfare and policy purposes