Supply- and output -side extensions to inoperability input -output model (IIM) with application to interdependencies of road transportation system
The Inoperability Input-Output Model (IIM) offers a macro-level view of infrastructure interdependencies estimated from the economic transactions of sectors. It defines inoperability as a measure of the state of the sectors after a perturbation scenario. This dissertation builds on the theories and methodology of the IIM by extending the classes of perturbation that can be investigated; specifically, perturbations to value-added factors of production and output levels. The dissertation postulates that perturbations can be in terms of either quantity or price changes, resulting to demand-quantity and supply-price models. The equivalence of the two models is proved by showing the primal-dual relationship of the models and the derivation of the relationships of technical coefficients and perturbation vectors. Additional linkage measures are also defined, namely, the output-output factor, output-final demand, and output-value-added factor, which measures the extent by which the operation of a sector can affect other sectors, the available supply for final consumption, and the value-added factor. The demand-, supply-, and output-side models are integrated using a sequential perturbation approach. In the case of simultaneous multiple perturbations, binding conditions are outlined to determine the dominant perturbation. A case study using the Virginia 1997 data is presented, which yields different sector impacts results depending on the different perturbation classes (demand or supply, quantity or price). The application of IIM to road transportation is also investigated using the link delay function to compute for both distance and time delays. The analysis provided a conversion of network flow performance to monetary terms with minimal data requirement (detour, speed limit, volume, capacity). This delay cost is then related to IIM perturbation by interpreting it as a productivity loss resulting in either a quantity perturbation or a price perturbation. A physical-based input-output model of the road transportation network is developed, translating the I-O variables into measures of traffic flow. The model allows for the cause-effect analysis of external perturbation to traffic flow, especially applicable to analysis of "through" commodity flow, identifying key links that can become bottlenecks when there is a significant change to the volume of commodity being shipped "through" a region.
0796: Operations research