%0 Journal Article %T Implementability by a Canonical Indirect Mechanism of an Optimal Two-Dimensional Direct Mechanism %A Naoki Kojima %J Theoretical Economics Letters %P 187-192 %@ 2162-2086 %D 2017 %I Scientific Research Publishing %R 10.4236/tel.2017.72016 %X The present paper investigates the multi-dimensional mechanism design in which buyers have taste and budget as their private information. The paper shows an easy proof of a two-dimensional optimal direct mechanism by a one-dimensional indirect mechanism: A canonical mechanism in the traditional one-dimensional setting, i.e., function of one variable, the buyer¡¯s taste. It also sheds light on where the difficulty lies implementability of a general direct mechanism¡ªnot optimal¡ªby a canonical mechanism. %K Multi-Dimensional Mechanism %K Indirect Mechanism %K Budget Constraint %K Revelation Principle %U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=74398