Would contact with extraterrestrials benefit or harm humanity? A   scenario analysis
  While humanity has not yet observed any extraterrestrial intelligence (ETI), contact with ETI remains possible. Contact could occur through a broad range of scenarios that have varying consequences for humanity. However, many discussions of this question assume that contact will follow a particular scenario that derives from the hopes and fears of the author. In this paper, we analyze a broad range of contact scenarios in terms of whether contact with ETI would benefit or harm humanity. This type of broad analysis can help us prepare for actual contact with ETI even if the details of contact do not fully resemble any specific scenario. 
Seth D. Baum, Jacob D. Haqq-Misra, Shawn D. Domagal-Goldman
physics.pop-ph