I can think of three reasons why somebody should try to get better at overcoming bias:
1. OB is a hobby: It should be pursued by people who enjoy it and/or who think it will pay off somehow.
2. OB is a virtue: It is part of a well-lived life (for a bit of this, see the preface to Facing Up by the physicist Steven Weinberg).
3. OB is a moral obligation: You should do it because it will cause you to do more good and less evil.
A recent post by Robin (responding to earlier remarks by Tyler Cowen) caused me to leave the following comment:
It sounds like you’re arguing here that overcoming bias is something like learning a martial art; whether or not you should do it depends mostly on whether it suits you, but it might also come in handy someday. But isn’t the point of this blog that OB is a positive virtue that *everyone* should seek to acquire?
To which Robin replied:
David, we should distinguish a weak claim, that given our ends we are reasonable to join together here to overcome bias, from a strong claim, that everyone should do so. The weak claim can be true even if the strong claim is not.
I’m not sure if he means that #1 alone could in principle be sufficient reason for us to join together on this blog (which is surely true), or if he means that it is in fact his sole reason. I certainly buy into Reason #2 for myself, and I buy into it as being prescriptive for other people as well, but only to a limited extent (basically the extent to which I might try to convince someone of the obviously true fact that being a Yankee fan is a virtue and that being a Red Sox fan is a vice and that this is not a matter of taste; it’s a pity if they don’t get it, but it would be wrong for me to cram it down their throats). But the big one is #3. Most of the evil in the world is done directly in the service of irrationality and much of the rest (i.e., evil that is done for rationally selfish reasons) uses some kind of irrationality as a cover story. So I’m not sure about Robin, but I think that OB is something that everyone should be encouraged to do a lot of, though not necessarily to do it to the maximum possible extent (like everything else, OB is subject to diminishing marginal returns and, as Tyler pointed out in the original post, the marginal returns might eventually become negative, though I think this is true a lot less often than he seems to thinks it is).