Re: One question and a comment
"...Why should people's valuation of a company affect that company's bottom line?"
Well, of course, in fact it doesn't, except to the extent that the company owns stock in itself -- a remarkable concept. The glitch comes with the definition of "shareholder value". This is by modern definition the goal of a corporation -- to produce value for its shareholders. If the company can manipulate the stock market so as to increase the value of its stock, that brings shareholder value -- and, as you say, creates bubbles and slumps. One abstraction too many.
My own modest proposal :-) is to (1) allow corporations to deduct dividends from gross income for tax purposes, and (2) institute a "churning surtax" to make up for the revenue loss from #1. This would in fact be a tax increase, since the recipients of the said dividends would be paying income tax on them, but some sop to the Left-Liberals is called for. The churning surtax would be a stamp tax on exchanges of securities of all types; a very small percentage, multiplied by the maturity of the security, divided by the time held. Common stocks would be considered to have a synthetic maturity of either five or ten years, depending on the age of the corporation. Both times would be calculated in days; thus, if the base percentage was 0.1% of the transaction, the tax on a day trade would be 0.1% x (5 x 360) / 1 = 180% of the transaction amount... direct sale or other transfer of the security by the issuer would be exempt, and all securities held by an individual would be assumed to have reached maturity at the death of the owner.
As for employees -- how about capitalizing training? Then depreciating it? A sizeable percentage of a new-hire's salary would be totted up in the capital account, as when you buy a new machine. This would continue, with a decreasing percentage, over say the first ten (?) years of employment. Beginning then, the corporation could depreciate the training. Depreciation, as a decrease in the capital account, counts as income... Hey, lots of the "capital" of many corporations is the ethereal "goodwill". Why not "Employee training" as a capital, depreciable asset?
Regards,
Ric