Some of the interrelations between communication and economics, the cost analysis of purposive communication projects, and cost- effectiveness and cost-benefit analysis in general, are all discussed. A methodology for assembling costs and a checklist of cost and finance areas to be examined are presented for mass- communication projects, and then a table showing the results of cost-analysis for several educational technology projects is presented. Cost-effectiveness is defined as seeking to maximize "output" for a fixed cost or minimize cost for a given level of output. Cost-benefit analysis is presented as including cost- effectiveness, but going beyond it in attempting to assign monetary values to different output combination. A specific example of cost-effectiveness analysis and of cost-benefit analysis are given.