Eleven teams of experts were solicitated to provide a ranked list of the 50 statistically-most-concerning objects in LEO. The approaches used by the experts and resulting lists are described in McKnight et al.(2021). An aggregation rule that leads to a collective list is also proposed. This paper offers a view from social choice theory on the aggregation process. We show that different aggregation rules may yield different conclusions concerning the most concerning object. We also discuss alternative aggregation rules, and provide some recommandations concerning the question that could be addressed to experts.
