Behavioral Macroeconomics Via Sparse Dynamic Programming

56 Pages Posted: 12 Jan 2016

See all articles by Xavier Gabaix

Xavier Gabaix

Harvard University - Department of Economics; National Bureau of Economic Research (NBER); Centre for Economic Policy Research (CEPR); European Corporate Governance Institute (ECGI)

Multiple version iconThere are 3 versions of this paper

Date Written: December 2015

Abstract

This paper proposes a tractable way to model boundedly rational dynamic programming. The agent uses an endogenously simplified, or "sparse," model of the world and the consequences of his actions and acts according to a behavioral Bellman equation. The framework yields a behavioral version of some of the canonical models in macroeconomics and finance. In the life-cycle model, the agent initially does not pay much attention to retirement and undersaves; late in life, he progressively saves more, generating realistic dynamics. In the consumption-savings model, the consumer decides to pay little or no attention to the interest rate and more attention to his income. Ricardian equivalence and the Lucas critique partially fail because the consumer may not pay full attention to taxes and policy changes. In a Mertonstyle dynamic portfolio choice problem, the agent endogenously pays limited or no attention to the varying equity premium and hedging demand terms. Finally, in the neoclassical growth model, agents act on a simplified model of the macroeconomy; in equilibrium, fluctuations are larger and more persistent.

Keywords: Bounded rationality, inattention, simplification

JEL Classification: D03, E03, E21, E6, G02

Suggested Citation

Gabaix, Xavier, Behavioral Macroeconomics Via Sparse Dynamic Programming (December 2015). CEPR Discussion Paper No. DP11026. Available at SSRN: https://ssrn.com/abstract=2714266

Xavier Gabaix (Contact Author)

Harvard University - Department of Economics ( email )

Littauer Center
Cambridge, MA 02138
United States

National Bureau of Economic Research (NBER)

1050 Massachusetts Avenue
Cambridge, MA 02138
United States

Centre for Economic Policy Research (CEPR)

London
United Kingdom

European Corporate Governance Institute (ECGI)

c/o ECARES ULB CP 114
B-1050 Brussels
Belgium

Register to save articles to
your library

Register

Paper statistics

Downloads
0
Abstract Views
293
PlumX Metrics