A Law-and-Economics Perspective on Cost-Sharing Rules for a Condo Elevator

How to enhance the maintenance, repair and improvement of condo buildings? We address this issue by focusing on the case of an elevator installation whose benefits are not uniform across units. We examine the link between majority approval and cost sharing. Relying on a cooperative game theory approach, we prove the coalitional stability of any cost allocation which is such that the unit shares are a non-decreasing function of the floor level. Second, we show that the two surplus allocations induced, respectively, by the de facto cost-sharing rule used in France and the equal cost-sharing rule may fail to be coalitionally stable. By insisting that the cost sharing must depend on the relative individual advantages provided by an improvement, French law increases the risk of disputes between neighbors, compared to other sharing rules.