"I should be demanding such logic from you, not vice-versa!" Not hardly. You, not I, are postulating some advantage for new and novel accounting practices, and you still have provided no logic for them. The burden of proof is on he who proposes.
"Why would you assume that the same compilations would be well-suited for both purposes?" Why would you assume otherwise? Why, specifically, do you assume that what's sauce for the regulatory goose might be toxic for the investing gander? You neglect to address almost every point I made, and you continue with the unspoken premise that "market value" must have some sort of validity in relation to non-marketable investments (if only FASB will issue enough "guidelines", I guess). If you think banking regulators have some peculiar difficulty in "ascertaining whether the regulated companies can make good"--a difficulty that would be solved by a second set of books--you haven't dealt with many bank examiners. As for helping investors, I doubt that most investors can even understand the information they are already receiving. The flimsy concept of "core deposit intangibles" (another accounting creation), and the length of time those deceptive accounting entries may persist on a bank's books according to FASB guidelines, are a convenient example. Larding even more layers of information onto the financial reports is not going to assist investors. In fact, most accounting "innovations" make it more, not less, difficult for investors to decipher a business's basic financial condition. I would have thought that Enron, Arthur Andersen, and "special purpose entities" in general would have taught us that much.
I will bring up one final, obvious point. The move toward "market-value" accounting in banking has been progressing for close to twenty years now, complete with mandatory "shock-testing" and alternate computations of investment values under all sorts of scenarios. The development and use of these tools for "risk management" (and disclosure of many of the results to the public) was cited, in part--"Well, our risk management numbers show that this is all right!"--as justification for practices that would otherwise have been, and should have been, simply banned as "unsound banking practice", so: How well did all that accounting hocus-pocus serve us last year in helping inform either regulators or investors? The fix for most problems in not more of the same, although that is often the first suggestion.
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