Logarithmic laws in service quality perception: where microeconomics meets psychophysics and quality of experience

Utility functions, describing the value of a good or a resource from an end user's point of view, are widely used as an important ingredient for all sorts of microeconomic models. In the context of resource allocation in communication networks, a logarithmic version of utility usually serves as the standard example due to its simplicity and mathematical tractability. In this paper we argue that indeed there are much more (and better) reasons to consider logarithmic utilities as really paradigmatic, at least when it comes to characterizing user experience with specific telecommunication services. We justify this claim with the help of recent results from Quality of Experience (QoE) research, and demonstrate that, especially for Voice-over-IP and mobile broadband scenarios, there is increasing evidence that user experience and satisfaction follows logarithmic laws. Finally, we go even one step further and put these results into the broader context of the Weber-Fechner Law, a key principle in psychophysics describing the general relationship between the magnitude of a physical stimulus and its perceived intensity within the human sensory system.