A staff paper to the President's Task Force on Communications Policy analyses the use of the electromagnetic spectrum for communications and suggests improvements. The evolution of spectrum use and its present federal management are described together with the problem of achieving efficient use in the areas of electromagnetic congestion. Criticism centers on the "block" allocation plan, in which the spectrum is broken into sections each for the exclusive use of a class of users, rather than according to the particular needs of a geographical area. Lack of engineering of individual spectrum uses creates further waste. Although a free market system of allocation is rejected, greater incentives towards economy in band use is advocated. Spectrum engineering would allow individual operators to use the power, bandwidth, modulation and beam localization necessary to reduce spectrum waste. Crisis areas include land-mobile service, VHF and lower UHF, and television frequencies. (BB)