Jean-Pierre Drugeon

The importance of the literature on present bias may have overlooked some other forms of temporal inconsistencies anchored in the smoothing properties of consumption. The article first clarifies how a list of axioms enable the obtention of time-dependent recursive utility functions. The properties of the latters are analysed in light of the well-known present bias but also through a temporal smoothing bias that emerges when two successives selves do no share the same aversion to fluctuations. It is shown that this new concept relates to a time-varying Morishima intertemporal elasticity of substitution. The second part of the article brings an axiomatic construction providing a parametric representation that is aimed at a careful account of future and present bias, how they relate to each other or to substitution mechanisms and is finally concerned with the testable implications of the current framework. The theory is finally applied by considering intertemporal choices with Markovian strategies and temporally consistent solutions. For some parameters configurations, there exists a multiplicity of Nash equilibria, and then an indeterminacy in the agent behaviour.

This article is interested in future allocations of scarce resources in an environment where upper bounds and lower bounds are fixed on the stream of consumptions or extractions of the scarce resource. It is shown that we can compute the optimal planning of consumptions independently from an explicit sequence of discounting factors as soon as they are decreasing at a rate smaller than a bound linked to the concavity of the utility function and the choice of the sequences of lower and upper bounds. The optimal solution is unique and exhibits two regimes with a pivotal period in the middle. Therefore, one gets plans satisfying some kind of intergenerational fairness: while the highest e ort is supported by the first generations, it then decreases for the remaining ones. The argument is then extended to partially renewable resources. Finally, we consider the role of the horizon and of a potential regret after a revision for the bounds.

This article considers a three-period-lived pure exchange overlapping generations economy and clarifies the role of market complementarities in the scope for Kehoe & Levine’s convergence criterion in order to reduce the size of continuation equilibria and establish uniqueness and determinacy. The argument is based upon the price-relatedness of dated goods and the way the law of demand, gross substitutability and the scope for asymmetric complementarities come into play when three periods lifespans are considered. The nature of these restriions is clarified in the context of stationary economies and the way it relates to equilibrium continuation and Kehoe & Levine’s determinacy is made precise. A detailed articulation between complementarities and determinacy is finally provided in the context of Samuelson intermediate economies. The key role of dated goods spaced one period apart and entering in an additive way is emphasised in the determinacy result while the importance of asymetric complementarities between isolated goods spaced two periods apart is also pointed out.

This paper provides a framework for understanding preferences over utility streams across different time periods. We analyze preferences for the close future, for the distant future, and a synthesis of both, establishing a representation involving weights over time periods. Examining scenarios where two utility streams cannot be robustly compared to each other, we introduce notions in which one has more “potential” to be preferred over another, which lead to MaxMin, MaxMax, and -MaxMin representations. Finally, we consider temporal bias in the form of violations of stationarity. For close future preferences, we obtain a generalization of quasi-hyperbolic discounting. For distant future preferences, we obtain Banach limits and discuss the relationship with exponential discounting.