Population estimates are observed to play a central part in both the qualification of local areas for Federal programs and in the distribution of fiscal assistance funds. General Revenue Sharing is singled out as perhaps the most familiar and well supported program relying, at least in part, upon total population as a distribution mechanism. Local research resulting in population estimates is noted to have been adopted for use in such allocation systems for selected States. The Federal-State Cooperative Program for Local Population Estimates (FSCP) has strengthened these programs through joint State-Census Bureau efforts. It is speculated that similar arrangements may be possible for other currently active legislative programs based upon population characteristics. Contact with a newly formed FSCP subcommittee, a Census Bureau estimating methods research unit, or State-local cooperative groups emerging in some States are suggested potential avenues for local research to impact as many as 103 separate pieces of legislation depending upon some item of population information for operation of the program. Similar opportunities are identified for population projections. Although no legislation contains formal provisions for the use of projections to the degree now specified for current population estimates, projections are relied upon for the administration of programs in the Environmental Protection Agency and in the Department of Transportation. Other instances of projections used in planning applications are identified, as are the likely points of entry for local research work.