<prompt> Translate the following text to EnglishKwa mfano, utafiti wa Viscus na utafiti wa utafiti wa Viscus, unaonyesha kwamba Viscus na utafiti wake wa thamani ya maisha ni sawa.  <response>: The approach and set of selected studies mirrors that of Viscusi 1992 with the addition of two studies, and uses the same criteria as Viscusi in his review of value-of-life studies. 