Friday, November 21, 2014


Howard Gardner: "Among cognitive psychologists, there is widespread agreement that people learn best when they are actively engaged with a topic, have to actively problem solve, as we would put it 'construct meaning.' Yet, among individuals young and old, all over the world, there is a view that is incredibly difficult to dislodge. To wit: Education involves a transmission of knowledge/information from someone who is bigger and older (often called 'the sage on the stage') to someone who is shorter, younger, and lacks that knowledge/information. No matter how many constructivist examples and arguments are marshaled, this view — which I consider a misconception — bounces back. And it seems to be held equally by young and old, by individuals who succeeded in school as well as by individuals who failed miserably. Now this is not a scientific misconception in the sense of flat earth or six days of creation, but it is an example of a conception that is extraordinarily robust, even though almost no one who has studied cognition seriously believes it hold water. "

Saturday, November 08, 2014

Understanding "one in a million" in the age of big data

This is a great article for several reasons. My short version of what it says is: if you evaluate one million million-to-one propositions, it is likely enough that one of them will be "true".

First, it reinforces the idea, well-known in many quarters, that it is possible to be a superior stock-market trader. It particularly undercuts the idea of "technical analysis", something I have always doubted and dismissed.

Second, I've always thought this is one of the things that causes people to assign meaning to improbable but coincidental events in daily life. The hours and years of daily life offer so many different opportunities for patterns to emerge, everyone is bound to experience a few that seem remarkable, but are nevertheless entirely coincidental. (You may at this point call me unromantic or bloodless--I prefer the former, but I'll answer to either :) )

Third, although I'm not sure the article explicitly makes this point, it is yet another cautionary tale of the dangers of mixing correlation and causation. The most aesthetically pleasing way to discovery is to first formulate a theory, and then to prove it with data. Next best is to proceed from observational data, to formulate a well-constructed, internally-consistent theory that relies on well-known first principles. Less appealing is to find a correlation in data, and to construct a theory from it, using new principles that may amount to a post-hoc explanation, rather than time-tested principles. Worst of all is to take a statistical observation as law, without any underlying theory at all.

Friday, November 07, 2014

NFC Receipts (Apple Pay)

I've been a bit of an NFC-payments doubter. Not hardcore, but swiping a credit card is not all that hard, so the motivation to uptake is not that high. But if paying by NFC got me an NFC receipt, and that NFC receipt were automatically entered into my account, that would be a major value-add.

Saturday, November 01, 2014

Analysis of Differential Tax Rate Impacts on Timinig of Exercising SARS

Okay, the title is a bit of a joke, I am sure the quality of this analysis is nowhere near the kind of academic rigor that title suggests. (Heck, it's not even peer-reviewed, so there is always the possibility I am just outright wrong.)

Anyway, the proposition I wanted to evaluate: if one has SARS (Stock-Appreciation Rights) that are significantly above water, is there a benefit to exercising them early, for the sole purpose of ensuring all future gains are taxed as long-term capital gains (LTCG), at a rate of 15% + State? In MN, that would equate to about 22% in the typical case. As opposed to holding them as long as possible, in which case all gains will be taxed as ordinary income (OI), at a rate of 28% + State? Again, in MN that would be about 35%.

To cut to the chase, the answer is an emphatic no, do not sell prematurely for tax considerations!!!

This is what I thought going in. A general rule of investing is that tax considerations should take a back-seat to investment strategy (don't let the tax tail was the investment dog). The reason I had to work this out to convince myself, though, is because of the rate differential. I wanted to see if cashing out at some early point, and thereby subjecting all future returns to the much lower LTCG rate, would offset the benefit of deferring taxation as long as possible by holding to maturity.

I am fairly confident that cashing out early is not optimal, under any scenario, given my reasonable, simplifying assumptions. Those are:
  • No market timing. Uniform rate of return for all years. Obviously this is not what happens real-world, but over a reasonable long time-horizon, it should be a good approximation.
  • Early-exercise proceeds, net of taxes, are immediately reinvested in the same stock (with zero transaction costs).
The model pasted below uses a 6% return on capital, and a 20-year time horizon. For simplicity, it assumes a grant value of $10,000, but any grant value will illustrate the same results. I played with all the parameters, and they affected the relative penalty of early exercise, but never resulted in a scenario where early exercise was optimal.

(A copy of my model is available here.)

So in the scenario above, each row shows the NFV of the investment at 20 years, if it were subject to early exercise at the year denoted in the row. For example, if the initial grant of $10,000 were cashed in at the end of Year 4, and immediately reinvested in the same stock, the value after 20 years would be $3,756. Whereas if held to its 20-year "maturity", the value would be $14,346.

In hindsight, the explanation is blindingly obvious. Before you cash in, you have the entire $10,000 basis working for you. At the point you cash in, you only have whatever you have gained working for you. I think it is a bit analogous to killing the goose that lays the golden eggs, thinking you can invest all those unlaid eggs now, versus taking and investing the eggs as they come.

Concluding thought: The idea of  attempting "market timing"--never a good idea--is wildly inadvisable in the case of SARS (and I think much the same analysis goes for stock options).