Data foundation for a simultaneously physically and environmentally extended economic input-output model framework

A physical assessment of material flows in an economy (e.g., material flow quantification) can support the development of sustainable decarbonization and circularity strategies by providing the tangible physical context of industrial production quantities and supply chain relationships. However, completing a physical assessment is challenging due to the scarcity of high-quality raw data and poor harmonization across industry classification systems used in data reporting. This thesis focuses on developing the data foundation for a proposed framework that simultaneously physically and environmentally extends an input-output model. In the model framework, the U.S. economy is divided into goods- and service-producing subsectors, and mass flows are quantified for each goods-producing subsector using a combination of primary source physical production data (e.g., U.S. Geological Survey), imputed values based on trade data (e.g., UN Comtrade), and estimations based on mass balance considerations. Given that primary source production data (in physical units) are not available for all subsectors, price-imputation and mass-balance assumptions were developed to complete the physical flows dataset that were then used alongside total emissions data to calculate emission factors on a mass basis (kg CO₂-eq/kg). Where primary source data are available, the estimation techniques are compared to assess data quality, and the results show that the price-driven estimations are vulnerable to error based on a subsector’s involvement in trade. The estimation techniques developed in this thesis can help to fill the physical production data gap while addressing the limitations on the applicability of these production estimates for material and life cycle analysis. This work is designed to be integrated with existing EEIO tools, such as the U.S. Department of Energy’s EEIO for Industrial Decarbonization (EEIO-IDA) model, to enable the quantification of environmental impact intensity metrics on a mass basis within industrial subsectors and across supply chains.