The paper discusses the theory and methodology supporting the development of the inoperability input-output model (IIM). The IIM is based on Leontief’s input-output model, which characterizes interdependencies among sectors in the economy and analyzes initial disruptions to a set of sectors and the resulting ripple effects. An advantage of building on Leontief’s model is that it is supported by publications of the Bureau of Economic Analysis. Independent computer runs of the IIM can represent the entire nation or sectors within particular U.S. regions. A dynamic extension of the IIM analyzes different temporal frames of recovery and characterizes the required sector adjustments for achieving new production levels. The IIM can systemically prioritize and manage the sectors deemed to be economically critical and also identify those sectors whose continued operability is critical during recovery. A companion paper demonstrates applying the IIM to attacks on electric power and telecommunications.

The paper discusses case studies of the inoperability input-output model (IIM) for modeling impacts of willful attacks on interdependent sectors. The IIM is a model for assessing sector vulnerabilities using the inoperability and economic loss impact metrics. The case studies focus on high-altitude electromagnetic pulse (HEMP) attack scenarios. HEMP is an intense electromagnetic blast induced from high-elevation nuclear explosions, potentially causing damage to electronic and electrical systems. Parametric and uncertainty analyses are conducted for assessing (1) intensity of initial disruptions, (2) sector recovery characteristics, (3) economic loss reduction policies for critical sectors, and (4) regional scope of an attack. Sectors susceptible to a HEMP attack have been identified, including electric power, electronic equipment, and workforce. Trade-off analyses are performed to analyze the efficacy of resource allocation strategies associated with recovery. Recommendations from this paper include devel...