Inconsistent Planning: When in doubt, toss a coin!

TL;DR

This paper examines how randomness in decision-making affects the cost of irrationality in present-biased agents, proposing a modified model and analyzing its computational complexity.

Contribution

It introduces a randomized decision process into Kleinberg and Oren's model to better capture human choices among equally attractive options and studies its computational implications.

Findings

The cost of irrationality is sensitive to agent choices among equally valued actions.

A modified model with randomized selection is proposed to address this issue.

The computational complexity of estimating irrationality in the new model is analyzed.

Abstract

One of the most widespread human behavioral biases is the present bias -- the tendency to overestimate current costs by a bias factor. Kleinberg and Oren (2014) introduced an elegant graph-theoretical model of inconsistent planning capturing the behavior of a present-biased agent accomplishing a set of actions. The essential measure of the system introduced by Kleinberg and Oren is the cost of irrationality -- the ratio of the total cost of the actions performed by the present-biased agent to the optimal cost. This measure is vital for a task designer to estimate the aftermaths of human behavior related to time-inconsistent planning, including procrastination and abandonment. As we prove in this paper, the cost of irrationality is highly susceptible to the agent's choices when faced with a few possible actions of equal estimated costs. To address this issue, we propose a modification of Kleinberg-Oren's model of inconsistent planning. In our model, when an agent selects from several options of minimum prescribed cost, he uses a randomized procedure. We explore the algorithmic complexity of computing and estimating the cost of irrationality in the new model.