Hi Jason,
That's cool: I think I was just a little confused by the contexts in which you were talking about "discounting." And no, I would never suggest a negative discount rate.
Maybe my main difficulty is with the concept of "mispricing," so here's how I think of it. The "value" of any asset is the present-discounted value of its future stream of net cash flows. Many assets will have a different future stream of net cash flows depending on their owner: think, for example, of any stock (or bond) held by an activist shareholder, or any management-intensive asset such as a sole proprietorship or an income-producing building. The future stream of discount rates will also differ by owner, too, based on borrowing costs, other investment opportunities, etc. That means any asset has an owner-specific "value" in the hands of each potential owner. The "market value" of the asset is bracketed by the two potential owners with the highest and second-highest owner-specific values. In an efficient market those will collapse to a single market value, which is the transaction price, while in an inefficient market there may be a large range of transaction prices within those two owner-specific values.
My point is that each potential owner takes into account all available information regarding future net cash flows and future discount rates in determining her/his owner-specific "value," and therefore the market value will reflect all such information. Any market participant may do a poor job of forming expectations regarding future net cash flows and future discount rates. If the future turns out to be worse than expected, then whoever bought the asset will be disappointed--that's where the "winner's curse" comes from. Conversely, if the future turns out to be better than expected, everybody who didn't buy the asset will be disappointed--that's simply a different form of regret.
But it seems to me you're implying that errors in predicting the future are all going to be in one direction--and there's simply no basis for reaching that conclusion. One way to think about it is that there's a "margin of safety" built into the process: each person's owner-specific "value" is, in effect, the expected value of a distribution of possible future scenarios.
Philosophically, your argument reminds me of "Pascal's wager." Pascal said that we should all believe in God because if God exists then our failure to believe in God would have enormous negative consequences, whereas if God doesn't exist then there would be no consequences. The problem with Pascal's wager is that he didn't consider the possibility that we could be sentenced to hell (or something along those lines) for the crime of believing in God. So yes, we could be making big mistakes in the sense that future environmental conditions could be far worse than we realize--or, alternatively, we could be making big mistakes in the sense that future environmental conditions could be far BETTER than we realize.
Thanks.