Public radio can survive cutbacks in federal subsidies, but only if these funds are reduced no more rapidly than public radio can replace them with newly-generated audience-sensitive revenues (listener support and underwriting). A model developed in this analysis suggests a three-to-five year "glide path" to zero federal support. Public radio has been moving away from a subsidized economy toward a user-based economy for 15 years. Direct reliance on listeners and underwriting has caused certain changes in the very nature of the medium. Cutbacks in federal subsidies will accelerate changes already well underway. Certain vestigial privileges and mandates inherent in a subsidized economy are being displaced by the responsibilities and imperatives of a user-based economy. Meeting these responsibilities requires that public radio preserve the assets and enhance the endeavors that make it the valued public service that it is. Now more than ever it must serve significant audiences with significant programming--programming that is worth listening to and worth supporting. (Contains 8 graphs.) (Author)