Peer-punishment is effective in promoting cooperation, but the costs associated with punishing defectors often exceed the benefits for the group. It has been argued that centralized punishment institutions can overcome the detrimental effects of peer-punishment. However, this argument presupposes the existence of a legitimate authority and leaves an unresolved gap in the transition from peer-pu...

This article examines the modern urban planning situation and most important role of water in artistic solution architecture. When we talk about a park, must know "where are from where going." Human nature create divine harmony. One these landscape elements is water. She not only source life, but also pinnacle aesthetic pleasure.

Experimental studies have shown that sanctions effectively deter free riding within groups. However, the over-use of costly punishment may actually harm overall welfare. A main reason for over-punishment is that free-riders generate negative emotions that likely favor excessive punishments. In this paper we ask whether the venting of one’s emotions in different ways can reduce the level of exce...