Causal Reasoning Under Resource Constraints, Part II: Search Dynamics and Hypothesis Space Construction

This paper extends the resource-rational framework for causal reasoning introduced in Part I by focusing on the dynamics of hypothesis-space search during backward causal inference. While Part I established that backward reasoning is best characterized as constrained search over a hypothesis space, this paper formalizes the temporal dynamics of that search. We propose that hypothesis-space construction is not a one-time event but an iterative process shaped by the interplay between search costs, evidence accumulation, and stopping rules. The framework explains why causal search exhibits characteristic temporal patterns—early candidate generation, asymmetric evaluation, and satisficing termination—and how these patterns vary with resource availability. We derive testable predictions about search duration, hypothesis order effects, and the impact of time pressure on diagnostic accuracy. This work bridges cognitive models of reasoning with resource-rational analysis, providing a process-level account of how bounded agents navigate causal hypothesis spaces. The framework is grounded in Energy-Efficiency Theory (EET), linking cognitive costs to energy parameters \ (Ėₑ₄ₒ₏\) (response energy rate) and \ (Ė₌₀₈₍\) (maintenance energy rate), and their ratio \ (= Ėₑ₄ₒ₏ / Ė₌₀₈₍\).