A Prompt Report of an Additional Result on Noda (2015)

This is a prompt report of an additional result on Noda (2015), which investigates the condition for full surplus extraction in dynamic environments. We weakened a sufficient condition for within-period ex post implementation of arbitrary allocation rules, which have been proposed by Liu (2015) and Noda (2015). Indeed, the condition we characterize in this note is the necessary and sufficient condition for implementation guaranteed by the information structure, when we consider two-period environments (an environment where agents can receive an additional signal after an allocation, and the payment can depend on the report of such additional signals, originated by Mezzetti (2004)). We will combine this additional result with our former results (initial-period full surplus extraction given wp-EPIC mechanism) soon.