THE NEOCLASSICAL GROWTH MODEL WITH HETEROGENOUS QUASI-GEOMETRIC CONSUMERS

This paper studies how the assumption of quasi-geometric (quasi-hyperbolic) discounting affects the individual consumption-savings behavior in the context of the standard one-sector neoclassical growth model with heterogeneous agents. The agents are subject to idiosyncratic shocks and face borrowing constraints. We confine attention to an interior Markov recursive equilibrium. The consequence of quasi-geometric discounting is that the effective discount factor of an agent is not a constant, but an endogenous variable which depends on the agent's current state. We show, both analytically and by simulation, that this feature of the model can significantly affect its distributional implications.time inconsistency, quasi-geometric discounting, quasi-hyperbolic discounting, idiosyncratic shocks, wealth inequality.

Heterogeneous discounting in consumption-investment problems. Time consistent solutions

In this paper we analyze a stochastic continuous time model in finite horizon in which agents discount the instantaneous utility function and the final function at constant but different instantaneous discount rates of time preference. Within this context we can model problems in which, when the time t approaches to the final time, the valuation of the final function increases compared with previous valuations in a way that cannot be explained by using a unique constant or a variable discount rate. We derive a dynamic programming equation whose solutions are time-consistent Markov equilibria. For this class of time preferences, we study the classical consumption and portfolio rules model (Merton, 1971) for CRRA and CARA utility functions for time- consistent agents, and we compare the different equilibria with the time-inconsistent solutions. The introduction of stochastic terminal time is also discussed.dynamic programming, consumption and portfolio rules, heterogeneous discounting, time consistency

Multiple solutions under quasi-exponential discounting

We consider a group or committee that faces a binary decision under uncertainty. Each member holds some private information. Members agree which decision should be taken in each state of nature, had this been known, but they may attach different values to the two types of mistake that may occur. Most voting rules have a plethora of uninformative equilibria, and informative voting may be incompatible with equilibrium. We analyze an anonymous randomized majority rule that has a unique equilibrium. This equilibrium is strict, votes are informative, and the equilibrium implements the optimal decision with probability one in the limit as the committee size goes to infinity. We show that this also holds for the usual majority rule under certain perturbations of the behavioral assumptions: (i) a slight preference for voting according to one's conviction, and (ii) transparency and a slight preference for esteem. We also show that a slight probability for voting mistakes strengthens the incentive for informative voting.: time-consistency, hyperbolic discounting, stochastic dynamic programming, multiplicity, uniqueness.

Time-consistent renewable resource management with present bias and regime shifts

We investigate the extraction plan of present-biased decision makers managing a renew-able resource stock whose growth is uncertain and which could undergo a rapid and sig-nificant change when stock falls below a threshold. We show that the Markov-Nash equi-librium extraction policy is unique, time consistent, and increasing in resource stock. An increase in the threshold leads to increased resource extraction, rather than the precau-tionary reduction in extraction often observed with exponential discounting. An increase in the degree of present bias also leads to an increase in resource extraction. Our analy-sis suggests that accounting for and appropriately dealing with resource managers' present bias may be important to understand resource use sustainability.(c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/

Time-consistent renewable resource management with present bias and regime shifts

We investigate the extraction plan of present-biased decision makers managing a renewable resource stock whose growth is uncertain and which could undergo a rapid and significant change when stock falls below a threshold. We show that the Markov-Nash equilibrium extraction policy is unique, time consistent, and increasing in resource stock. An increase in the threshold leads to increased resource extraction, rather than the precautionary reduction in extraction often observed with exponential discounting. An increase in the degree of present bias also leads to an increase in resource extraction. Our analysis suggests that accounting for and appropriately dealing with resource managers’ present bias may be important to understand resource use sustainability

CLIMATE POLICY WHEN THE DISTANT FUTURE MATTERS: CATASTROPHIC EVENTS WITH HYPERBOLIC DISCOUNTING

Low probability catastrophic climate change can have a signifcant influence on policy under hyperbolic discounting. We compare the set of Markov Perfect Equilibria (MPE) to the optimal policy under time-consistent commitment. For some initial levels of risk there are multiple MPE; these may involve either excessive or insufficient stabilization effort. These results imply that even if the free-rider problem amongst contemporaneous decision-makers were solved, there may remain a coordination problem amongst successive generations of decision-makers. A numerical example shows that under plausible conditions society should respond vigorously to the threat of climate change.abrupt climate change, event uncertainty, catastrophic risk, hyperbolic discounting, Markov Perfect Equilibria, Environmental Economics and Policy, C61, C73, D63, D99, Q54,