Regional Sustainability Gap Index (RSGI): A White Paper

The Regional Sustainability Gap Index (RSGI) is a new measure designed to assess whether a region is on a sustainable economic path for its residents. The index combines two components: Mi, which measures the current wage gap between a county and the most economically active county in the state, and Ri, which measures each county’s wage-growth trajectory relative to that same frontier county. Together, Mi and Ri reveal not only a region’s present wage altitude but also the direction in which that wage horizon is moving. In Washington State, Mi reflects the distance between a county’s median wages and King County’s median wages, which define the state’s wage frontier. The RSGI provides a forward-looking way to evaluate regional opportunity structures, long-term competitiveness, and the ability of communities to retain and develop human capital.