The following appeared in a memo from a vice president of a large, highly diversified company. "Ten years ago our company had two new office buildings constructed as regional headquarters for two regions. The buildings were erected by different construction companies-Alpha and Zeta. Although the two buildings had identical floor plans, the building constructed by Zeta cost 30 percent more to build. However, that building's expenses for maintenance last year were only half those of Alpha's. Furthermore, the energy consumption of the Zeta building has been lower than that of the Alpha building every year since its construction. Such data indicate that we should use Zeta rather than Alpha for our contemplated new building project, even though Alpha's bid promises lower construction costs."