Estimating County to County Trade Flow

Abstract

Estimating count to county commodity trade flows is important for understanding a multitude of transportation, regional planning, and economic problems. While no primary data track intranational trade flows, gravity models have often been used to estimate these flows. However, to properly specify a gravity model, data on total commodity supply and total commodity demand for a consistent set of commodities and for every county must be obtained. Because these data are not available through primary data sources, a systematic process for estimating these values must be generated. This report details a process for starting with primary government data, specifically the quarterly census of employment and wages (QCEW) and national input-output accounts from the US Bureau of Economic Analysis (BEA), and generating employment, output, and commodity supplies and demands across 409 commodities in 3,142 counties. These commodity supplies and demands are then used in a gravity model to estimate bilateral trade for each commodity between every county in the United States. Employment, commodity trade data, and county to county trade totals are available at: https://tapestry.nkn.uidaho.edu/