Comment: Re:One more issue (Score 4, Interesting) 1064
I consider myself to favor progressive tax policies, but even I think this goes too far.
"Mark to market" has a lot of problems. As you say, the market price at any given moment in time simply reflects the price at which the most recent sale of any size was executed. There's no guarantee that any other sale would be executed at that price, and if a large volume of the item (or security) were to be sold all at once, it's unlikely that anything close to that price would be realized. So even leaving aside that this is a wealth tax rather than an income tax, it's not taxing actual wealth; it's taxing wealth assuming an arbitrary valuation.
This kind of thing could easily be gamed. Suppose at the end of the year someone arranged to sell a small block of securities at an artificially low price right at the closing bell? Presumably regulations could be passed to inhibit this, but I'm sure there would still be plenty of possibilities.
Furthermore, what happens when the security's price goes down? Does everyone holding it get a rebate? Or it is really nothing more than an annual wealth tax?
I'm not opposed on principle to a wealth tax, and I understand the issue of using an appreciated security as collateral to float a loan that could be more or less constantly renewed. And while a security's price is "stepped up" when passing through probate, I believe the estate still pays tax on the security's value at the time of death (but IANAL).