  We report the results of a computational study of repacking in the FCC
Incentive Auctions. Our interest lies in the structure and constraints of the
solution space of feasible repackings. Our analyses are "mechanism-free", in
the sense that they identify constraints that must hold regardless of the
reverse auction mechanism chosen or the prices offered for broadcaster
clearing. We examine topics such as the amount of spectrum that can be cleared
nationwide, the geographic distribution of broadcaster clearings required to
reach a clearing target, and the likelihood of reaching clearing targets under
various models for broadcaster participation. Our study uses FCC interference
data and a satisfiability-checking approach, and elucidates both the
unavoidable mathematical constraints on solutions imposed by interference, as
well as additional constraints imposed by assumptions on the participation
decisions of broadcasters.
