In this paper, a comparison between the concurrent multi-band and parallel single-band power amplifier architectures is analyzed. A generalized framework in which these two architectures can be compared in terms of cost, drain efficiency, output power, and linearity is developed. Results show that in general, a concurrent multi-band power amplifier will have worse performance than a parallel single-band amplifier for class-A operation, to the point that it is not a viable substitution. Class-B and class-C operation, however, remain viable alternatives for area savings without a large drop in efficiency and output power.