Intertemporal discrete choice

The discounted logit is widely used to estimate time preferences using data from field and laboratory experiments. Despite its popularity, it exhibits the "problem of the scale": choice probabilities depend on the scale of the value function. When applied to intertemporal choice, the problem the scale implies that logit probabilities are sensitive to the temporal distance between the choice and the outcomes. This is a failure of an intuitive requirement of stationarity although future values are discounted geometrically. As a consequence, patterns of choice following from the structure of the logit may be attributed to non-stationary discounting. We solve this problem introducing the discounted Luce rule. It retains the flexibility and simplicity of the logit while it satisfies stationarity. We characterize the model in two settings: dated outcomes and consumption streams. Relaxations of stationarity give observable restrictions characterizing hyperbolic and quasi-hyperbolic discounting. Lastly, we discuss an extension of the model to recursive stochastic choices with the present bias

Sartre: coscienza, autenticita' e malafede

In questo elaborato ho analizzato alcune delle principali opere di Jean Paul Sartre,facendo riferimento al rapporto tra autenticità e inautenticità come chiave di lettura delle opere sartriane. Ho concentrato la mia analisi in modo particolare sul tema della coscienza e dei rapporti intersoggettivi

When perfectionism becomes willpower

Perfectionism can be healthy: striving for perfection requires the ability to selfregulate, namely willpower. This paper formalizes the intuitive relation between healthy perfectionism and willpower in the presence of temptation. The value of a menu of options for an individual with limited willpower corresponds to the lower bound of the value assigned to the same menu by a perfectionist, when temptation and perfectionism intensities are free to vary. Moreover, the higher the perfectionism strive, the higher the willpower. The relation between overwhelming temptation and the Strotz model is a particular case of the result. When there is uncertainty about temptation, we generalize Dekel and Lipman (2012) providing conditions such that a preference is represented by a random willpower representation, if and only if, it has an equivalent random perfectionism representation

Deciding fast and slow

Empirical evidence suggests that choices are affected by the amount of time available to the decision maker. Time pressure or a cooling-off period (mandatory delay of choice) changes how choices are determined. Yet, few models are able to account for the role of available time on decisions. This paper proposes a dual-self model in which a fast and a slow self bargain to decide: the longer is the decision process, the higher is the bargaining power of the slow self when deciding. A large variety of behaviors observed under time pressure or cooling-off can be explained by our model. Quantitative predictions concerning the effect of nudging through time manipulation are also provided. We characterize the model imposing testable conditions on revealed preferences combined with non-choice data

An agglomeration-based massively parallel non-overlapping additive Schwarz preconditioner for high-order discontinuous Galerkin methods on polytopic grids

In this article we design and analyze a class of two-level non-overlapping additive Schwarz preconditioners for the solution of the linear system of equations stemming from discontinuous Galerkin discretizations of second-order elliptic partial differential equations on polytopic meshes. The preconditioner is based on a coarse space and a non-overlapping partition of the computational domain where local solvers are applied in parallel. In particular, the coarse space can potentially be chosen to be non-embedded with respect to the finer space; indeed it can be obtained from the fine grid by employing agglomeration and edge coarsening techniques. We investigate the dependence of the condition number of the preconditioned system with respect to the diffusion coefficient and the discretization parameters, i.e., the mesh size and the polynomial degree of the fine and coarse spaces. Numerical examples are presented which confirm the theoretical bounds