There is an excellent Radiolab piece on this:<p><a href="http:&#x2F;&#x2F;www.radiolab.org&#x2F;story&#x2F;what-year-life-worth&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.radiolab.org&#x2F;story&#x2F;what-year-life-worth&#x2F;</a>