<p>Chemical, biological, radiological, and nuclear (CBRN) events can take a catastrophic toll on human life, the environment, and the economy. This article first presents the beginnings of a framework for the analysis of behavioral aspects of population mobility in the aftermath of a CBRN event in terms of four phases: quarantine, evacuation, resettlement, and return. Population movements are often omitted from economic consequence analyses because of the difficulty of conceptualizing and estimating them. Through a synthesis of the literature in the context of our analytical framework, we provide estimates of the drivers of important dimensions of population mobility relating to compliance, geography, and timing for each major threat type. We also provide an assessment of error bounds on these estimates. Our findings indicate that omission of various dimensions of population mobility can lead to the underestimation of economic consequences of CBRN events by one or two orders of magnitude. The analysis is intended to point out the relative sensitivities of bottom-line economic impacts to the various population mobility dimensions, so as to guide researchers undertaking this estimation and to help prioritize future research on reducing uncertainties in the direction of drivers that are the most impactful.</p>