That an exact value cannot be arrived upon just by thinking about the issue in no way limits the usefulness of estimates. I have shown your estimate of the value of a single likely extinction to be completely out of whack. Your comment seems to indicate you believe I'm trying to arrive at a mathematically perfect resolution, and that my inability to do so is proof that my entire position is without merit. This could not be further from my intent. Any any charitable reading of my comments would have shown that clearly.

There is no species or even combination of species that is threatened by this oil spill that is LIKELY to have anywhere near the value you have assigned by any rational measure. That's my point. If you can't address that point, then there's really nothing more to discuss.