The estimates, to be published in the National Tax Journal by Mr. Chernick, David Copeland at Georgia State University and Andrew Reschovsky at the University of Wisconsin, are based on the mix of local revenue sources, the importance of state aid and the composition of jobs and wages in each city. The researchers predict average revenue shortfalls in the 2021 fiscal year of about 5.5 percent in a less severe scenario, or 9 percent in a more severe one.