Transportation-Based Framework for Deriving Perturbations to the Inoperability Input-Output Model

Abstract

The Inoperability Input-Output Model (IIM) provides a mechanism to enable examination of interdependencies among economic sectors to estimate the effects of a disruptive event. In previous IIM applications, parametric analyses were used to represent uncertain model inputs that created ambiguity in physical interpretations. This paper develops a transportation-based framework for decomposing the IIM inputs into two components: (1) workforce and (2) commodity flows. For workforce analysis, we estimate the number of workers using a particular asset, the normal income level, and the reduced income resulting from a disruption. For commodity analysis, we estimate the value of goods traveling across a particular asset and the resulting reduction due to a disruption. The workforce and commodity formulations were demonstrated using an ex post analysis of the 2003 closure of Virginia’s Midtown Tunnel. The study utilized a computer tool to execute the model and to perform sensitivity analysis to account for the data uncertainties.