UP World Expert Lecture Series: Prof. Krešimir Josić

You are all invited to attend the UP World Expert Lecture Series hosted by our institute on Friday, January 26, 2024, 2:00 PM.  This will be held at the Conference Room and via Zoom. Our speaker is Dr. Krešimir Josić  from the Department of Mathematics, University of Houston.

Dr. Krešimir Josić (Department of Mathematics, University of Houston)
Title: The Impact of Decision Order and Evidence Correlations on Decision Accuracy
Abstract: Drift-diffusion models are widely used to model how humans and other animals make decisions. Such models describe the accumulation of uncertain evidence that terminates with a commitment to a choice. I will show that the order in which decisions are made in a social group can strongly impact the accuracy of a decision: The first agent to decide almost always holds the strongest initial bias and decides accordingly. Slow agents, conversely, decide as if they have no initial bias. Hence, in large groups an early decision reflects on the initial bias of an agent, while a late decision is made as if the agent had no initial bias at all. These results hold when evidence is uncorrelated. I will therefore next discuss the impact of correlated evidence on decision accuracy. In this case even when agents are identical and unbiased, correlated evidence causes decision accuracy to depend on decision order. Early deciders are again less accurate than later ones. These phenomena occur despite the fact that the rational observers use the same decision criterion, so they are equally confident in their decisions. Although these are idealized models, our analysis offers general insights about the quality of decisions in groups of individuals that do not interchange information directly.