Exclusion of some forms of tax revenue and all forms of nontax revenue and support from measures of tax effort for allocating federal revenue sharing funds appears to introduce systematic bias against rural/nonmetropolitan local governments. Omitted tax revenues include those for schools and special districts (rural communitites raise proportionally more of their total taxes for these), while excluded nontax revenues include user charges, special assessments, donations, and various fund-raising activities for community services (fire protection, emergency ambulance). In addition, support in forms of volunteer effort and services like water supply, sewage treatment, and solid waste collection (generally privately provided or contracted for in rural communities) is eliminated. Nonmetropolitan communities disproportionately substitute user charges for general revenue financing, support a higher proportion of local government or community services with donations and fund-raising activities, substitute volunteer for paid effort more, and provide more community services privately than publicly. Estimates of impact on allocations to rural areas in Ohio when various excluded revenues are included bear out the apparent bias. If federal revenue sharing is to be equitable, either adjustments in measure of tax effort are needed or tax effort should be dropped as a criterion. (RS)