Thesis: The thesis is organized into three parts. The first two chapters deal with a model of deliberate preference change. According to this model, an agent becomes aware of new dimensions of the world over time and may decide to change they value system as a result, thus inducing a preference change. This model is entirely characterized by two normative foundations that are translated into axioms on choice behaviors across several consecutive periods. An application shows some features of the model and provides a possible explanation of political polarization. The third chapter studies the "forbidden fruit effect," a regularly observed phenomenon in which restricting an individual’s opportunity set redirects their attraction toward the forbidden options or their substitutes. We propose a model of choice that accounts for this phenomenon, the ingredients of which are identifiable by observing an agent’s reactions to restrictions, and which is characterized by five axioms about choice behaviors. We explore the consequences of the model in three applications: the first deals with the formation of conspiracy theories; the second with the backlash effect of integration policies for minorities; the third takes up a classical delegation problem in a principal-agent framework. We also derive a measure of the freedom of choice offered by the different sets of opportunities that the agent can face. The fourth and last chapter deals with the redistributive effects of personalized pricing. We show that maximizing consumer surplus while prioritizing the poorest consumers may imply giving an additional profit to the producer. We characterize the markets for which this is the case. We derive qualitative characteristics of the optimal price discrimination policy and thus derive a procedure to construct it.