Corrigendum to “Informational requirements of social choice rules” [Math. Social Sci. 57 (2009) 188-198]

I correct the statements of Theorems 3.1 and 3.2 and the proof of Theorem 3.1 in Sato (Informational requirements of social choice rules, Mathematical Social Sciences 57 (2009) 188-198). I add a condition requiring that each rule in the theorems does not choose the entire set of the alternatives when all agents have the same preference relation.