Commitment In Regulatory Spectrum Games: Examining The First-Player Advantage

Recent advances in dynamic spectrum sharing have led to renewed focus on the structure of regulatory games between a primary user and a secondary user of a spectrum band. The primary user has to decide to what extent it invokes the services of the regulator, and the secondary user has to decide how to operate in the spectrum band. This paper builds on a mathematical model for light-handed regulation using "spectrum jails" to show that the order of play and amount of commitment matters. A primary that can commit to its strategy before the game is able to increase its equilibrium payoff, even when the secondary best responds to the committed strategy. We compare the ensuing Stackelberg game with the simultaneous primary secondary game. We also introduce a new concept of partial commitment by which the primary can only commit to a range of strategies using a finite number of bits. We show explicitly that the more the primary commits to, the more it benefits, and that Stackelberg commitment can be understood as a limit of infinite "commitment bits".