1. Using this classification, a battle-of-the-sexes problem presents a collective action problem but not a coordination problem, because it does not satisfy the last clause.

2. This is a revised and slightly amplified version of the list discussed (with sources for the labels) in the appendix to Cullity 1995.

3. For a more accurate account of what really happened on Easter Island, see Boersema 2011 [2015].

4. But on lighthouses, see Coase 1974.