Overtaking criteria and supermodular payoff functions
This study revisits the overtaking criterion in economics, in a framework without the usual convex
structures that are often used to prove existence and convergence of optimal paths. We show that the
supermodular structure plays a decisive role in shaping the behavior of the economy. We further prove
that, as the discount factor approaches 1, optimal paths under standard discounting criteria converge
in the product topology to an optimal path under the overtaking criterion. This supports the view
that the overtaking criterion can be interpreted as a limiting case of discounting criteria with discount
factor equal to 1. Our arguments rely on turnpike properties, one for the overtaking problem and one
for the discounted problems.
Keywords: Overtaking criteria; Multiple discounting; Turnpike theory; Time preference; Dynamic
Programming
JEL Classification: C61, D15, D90, O41