Near-field and far-field extinction and scattering efficiencies for UV-vis-irradiated spherical gold nanoparticles of varying size have been estimated as a function of the radiation wavelength. Several different dielectric function models are used to explore the role of quantum-size effects. The results suggest that the utilization of bulk dielectric data does not capture quantitatively important size effects and may correspond to an unjustified oversimplification.