Category Archives: natural-world

A Gang of One

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Here’s a fun variant of the repeated prisoner’s dilemma game.

Picture a lecture audience. I announce that I’ll go along every row, starting at the front, and give each member a chance to say “cooperate” or “defect.” Each time someone says “cooperate” I’ll award ten cents to her and to everyone else in the audience. Each time someone says “defect” I’ll award a dollar only to her. And I ask that they play this game solely to maximize their individual total income, without worrying about friendship, politeness, the common good, etc. I say that I will stop at an unpredictable point after at least twenty players have played, at which time each member can collect her earnings.

You gotta love the instruction not to be “worrying about friendship, politeness, the common good, etc.” The game creates a group out of the audience with all the group dynamics in play particularly because there is no privacy. In the original prisoner’s dilemma that players are part of a gang, here we make the audience into a gang; while instructing them not to act like one.

That framing is from an interesting synopsis of a set of some ideas that apparently were first formalized by George Ainslie, e.g. that we all prefer short term pleasures and we tend to severely discount long term benefits as we make our choices in life. Given the choice between a chocolate bar right now and a chocolate cake tomorrow we tend to take the chocolate bar. This behavioral default is apparently well documented in man and other animals.

Formally we ought to discount future rewards by some reasonably uniform rate. So if we are offered a $100 tomorrow and $10 in an hour we ought to just compute the option value of each discounting by some interest rate based on the risk we percieve the future payoff to have. This kind of discounting is expediential; and it isn’t biased about things that are closer vs. farther away. It will cough up the same answer for 5 today vs. 10 tomorrow no matter what units (days, weeks, years) you use when you ask.

We animals don’t do that. Another way of saying that we like short-term benefits is that we discount things in small time units very sharply. A cookie in 30 seconds vs. a nice lunch in an hour? The cookie wins. It’s not rational but it’s how we are wired.

This leads to all kinds of common but irrational behaviors. Breaking the diet, staying up to late, having a few too many beers, failing to hold our tongue, etc. etc.

But most interestingly it puts us into a game just like the one above with ourselves. We are the audience. At each step in the game we have a choice to defect and take the dollar; but if we can manage not to defect then we can capture the long-term gains. We are caught in a gang of one our loyalty to our future selves continually tested against a hardwired setting that tempts us into short term defections.

Mast Year, Network Failure, and Information Cascades

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Tree’s don’t get around much, but they still engage extremely syncrhronized behaviors. From time to time all the trees of a given species though out a region will decide to throw a party. These are known as mast years. In these years all the trees in the region will produce vastly more seeds than in other years. It’s an orgy! The distribution of seed production/year is highly skewed with the majority of seeds being produced in these mast years.

I’ve been thinking about power failures, in particularly electrical power failures. Random failures in the power grid pop up all the time, but with surprising regularity large swaths of the power grid fail. I suspect that if you had a plot of the # of customers-days of various failures you’d get a highly skew’d distribution. We know a fair amount of why these grid failures happen. The grid isn’t a grid, it’s a scalefree network. If it were more like a grid then it would be more robust; but a grid is expensive compaired to a scale free network. The grid failures arise because a random failure hits some reasonably key component and then the rest of the grid fails as the problem cascades thru the network.

For example last summer, or the summer before, we had a power grid failure across the megalopolis on the east coast of the North America. The network was running at capacity that hot day when something near Ohio failed. As the load shifted the safety triggers on other components decided that they should resign from the network – to protect themselves. Each resignation accelerated the cascade and soon a hundred million people were without power. I found that interesting at the time because it makes a link between the issues of pure go-it-alone self interested capitalism and the issues of collective good. We have been playing out a recent enthusiasm for handing public goods over to private actors here in the US. These private actors have trouble successfully coordinating the building of enough excess capacity and reliablity into their networks. As the network failures become more likely the individual actors, seeing that their capital equipment is more at risk, tend to shift their safety triggers down; or at least i presume they would.

This year we had a example that’s worse, in it’s way, of a power grid failure. The grid in Queen’s New York failed. This time it appears the the safety triggers were set too high. Again during record load a component failed; but this time as the failures cascaded other components stayed loyal to the network with the result that rather than resign they committed sucide. Which is way bad because to reboot the system they have to pull new cables to replace the ones that burnt out.

Both those models are, to be clear, entirely speculative. But I’d love to know if after the first failure the guys in Queens went around and readjusted thier safety triggers.

The mass years, presumably, are information cascades thru some communication channel the species members have stumbled upon. I bet that when they figure it out they will discover that larger groves of trees play a role in triggering a successfull cascade.

Trees, like other members of the ecology, are embedded in an web of inter-species relationships. Observers have noticed that the mass years throw quite a ripple thru that web.  The squirrels get fat when oaks have a mass year.  They have lots of offspring.  The orgy cascades. The population bubbles and the next year it starves. This  pattern is actually good for the oaks; who would like to get their seeds past those pests.  During the abundant year many seeds get past the squirrels. The following year every acorn is found by now desperate squirrels.  By the third year most of the squirrels have died and the oak can again get a lot of acorns past those pests.

I bet there are similar patterns in the supply chain web after each of these power failures. For example I bet there comes season a bit after a large grid failure when you can get a generator really cheap from a vendor who was fat and happy just a season ago.

Learning at the Knee of a Random Number Generator

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Here’s a thought provoking intersection between behaviorism and statistical thinking; plucked out of this book.

Here’s a very naive model of behaviorism: If the animal behaves well we reward him, and if he behaves poorly we punish him. This primitive version of behaviorism is fraught with problems; but it will do for this discussion.

A very naive statistical model of behavior breaks into two parts; with average behavior and random behavior around that. Animal trainers are experts in leveraging that random bit. If you want to train a goldfish to swim clockwise then before you feed him then you wait for the random clockwise turn before feeding.

Of course animal training is a two way street. Pets expend a great deal of effort attempting to train their owners to feed them. It’s fun to walk in front of the tanks at a large pet store wearing the same color shirt as the staff an watch the fish attempt to trigger your into feeding them.

The hope of training is that you shift the average; but that takes time and in the meanwhile random variations will generate occasional good and bad performances relative to the mean.

So here’s the rub. If the animal behaves in an exceptionally good or bad manner it is likely that in following period his behaviors will return to the previous average behavior. In the jargon of statistics this is an example of regression to the mean.

Regression to the mean is enough to train a bad behavior in the trainer! Consider this scenario: the animal behaves well, the trainer rewards him, and then in the following training rounds the animal is certain to regress back toward his average behavior. The trainer learns from that the reward triggered the regression. The trainer learns not to reward. Which is bogus.

But it get’s worse. Consider this scenario: the animal behaves badly, the trainer punishes the behavior, and then in the following rounds the animal’s behavior randomly regresses back to the mean. The trainer learns that punishment precedes behavior improvements and; not because the animal is learning anything but because the statistics say so. The statistics alone are enough to train the trainer to punish bad behavior but not reward good behavior.

This is very bad!  It’s a fundamental insight of sophisticated behaviorism that punishment is far less effective than rewards; so much so that punishment often doesn’t work at all! Only a stupid or a captive animal will put up with training based on punishment. This problem is redoubled because if you punish the animals become more cautious; which reduces the not just the random variance (which you need) but also suppresses the smart active searching you want the animals doing. Punishment doesn’t work on smart animals and when you can get away with it makes the animal become stupid.

What a mess! Notice that you don’t need an animal to teach the trainer this bogus behavior pattern of never reward, but do punish. If you had the trainer work to train a random number generator he’d learn the same lesson. There really isn’t a more stupid beast than a random number generator. Which I think goes a long way toward explaining why fans of punishment often describe the animals they are trying to train as stupid.

Shangri-La Diet

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The Shangri-La diet Shangri-la Diet book is out; it’s eccentric author is doing his book tour; the echos of the PR machine are reverberating thru the media ecosystem; and apparently I’m not immune to their effects. Darn!

What caught me was two things. This fun cheerful paper on “Self Experimentation” by the diet’s inventor Seth Roberts. What really did me in though was more than 30 years ago when I first became interested in cults I read my way through some marvellously silly books written by “Jane Roberts.” Jane’s gig was channeling, she would channel a dude name Seth. It’s a great exemplar of the art of speaking like a mystic; you know stuff like: “transforming invisible atoms into the dazzling theater of the world.” One side effect is that whenever I hear the name Seth I tend to get a foxy smile, and this time the name Roberts too!

I might not even have read the paper on self experimentation if it hadn’t been authored for inclusion in a book on behaviorism. I’m a huge fan of practical behaviorism; and I often recommend Jane Pryor’s book “Don’t shoot the Dog.” It’s delightful and a far better thing to read than this new diet book.

The diet turns about to be behaviorist at its core. Animals all (really all of them apparently) are very good at learning causal chains of behaviors; most of which end in food. The classic version of this is Pavloff’s dogs who he noticed would salivate when he rang the dinner bell; rather than when the food showed up. Animal trainers can do amazing things with these causal chains getting animals to walk around on two feet, jump through flaming rings, roll over, etc. etc. all just for a treat. The behaviorists have written libraries full of papers about the fine tuning of these causal chains, how to strengthen them, weaken them, extend them, etc. etc.

So the trick at the heart of Robert’s scheme is to weaken the causal chain between taste and calories. Consider the animal that has built a link between a bell and dinner. If that animal wants calories it craves the bell; it’s weird but true. Now of course a bell isn’t calories so we can weaken that link in two simple ways. We could randomly ring the bell so the animal abandons it’s illusion that these two things are linked. Plan B is we could stop ringing the bell before meals. Either will work just fine; though as the behaviorist research shows these links can be surprisingly robust if they have been trained up just right.

Robert discovered that both tricks appear to work. That he could reduce the body’s craving for food (aka taste) by either means. He could providing a lot of random tastes so it wouldn’t build a strong link between them. He even found articles in the literature of experiments where animals whose food was flavored somewhat at random – they stopped eating so much. He could also break the linkage by providing calories with zero flavor.    In both cases is the outcome is a weakened causal chain between taste and calories; which in turn leads to reduced craving for food.

The theory is somewhat more complex than I’m making it here. You’d have no trouble finding a few dozen explainations if you poke around in the web. But for me I was particularly taken to see a diet based on such an extremely simple confident application of behaviorism.

Stratosphere comes to visit

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We are about to have a big storm here in Boston. My favorite part of the forecast discussion:

“Cross sections show potential for tropopause fold and gravity wave formation SE of i-95 midday Sun, as conditions appear favorable for stratospheric intrusion in this region.”

Sounds like that pseudo-science they toss about in sci-fi TV shows.

Captain! Long range sensors indicate a stratospheric intrusion!

“Woo Wow,” Snowy cries “Might that create the potential for a tropopause fold?”

Tompson! Engage the gravity wave!

Behoof

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I’d always presumed that the word ‘behoove’ meant, in effect, that one should ‘get a move on.’ I’d assumed that “hoove” had the same root as hoof, i.e. a horse’s foot. I found that amusing. But then I’m a sucker for foolish made-up games about word roots.

But it turns out that that ‘hoove’ like ‘have’ out of the root ‘kap’. Kap is also an ancestor of words like captive, accept, even deception. and recipe.

How big?

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This morning a oil terminal outside of London blew up. The paper says the terminal handles “2.37 million metric tonnes of petrol and other oil products a year”.

How much is that? It’s about 19 million bbl/year (if I assume 8 barrels/ton (see here). or 51 thousand bbl/day. For comparison the Gulf of Mexico has about 500,000 barrels a day shutin right now. So it’s about a tenth the impact of that. That sounds big.

Let’s try another approach. The bottom of this page it says that on average a thousand people consume 31 barrels of oil/day, but scanning the table suggests that Britain probably consumes something more like 35 or 40. So, using the 31 bbl/day, that terminal handled the oil for 1.4 million people. London’s population is 7.4 million, England and Wales is 54 million.

I gather that this terminal had a pipeline to Heathrow airport, but I haven’t found how much fuel the airport consumes per day.

Cones

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My university had a cruel architecture program. They would admit a mess of kids and then flunk 70% of the in the first semester. The process involved lots of amazingly hard design problems; like “Create a small unmarked uniform box which the instructor will place on table right side up on his first attempt, no text is allowed. Due tomorrow.” Did I mention the art supply store was closed?

Watching people work on these made me much more aware of design, and its curious perversities, and that some instructors are sadists.

I was reminded of that today glancing at my screen with my glasses off. There was a wonderfully ambiguous icon on the screen. It was either a triangle pointing to the left; or it was a volume control showing a speaker facing to the right. I’d not noticed this before. A cone is ambiguous about which way it is facing.

Petrol and Gas

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I filled up the car yesterday for $2.19 a gallon. That’s not the typical price here in the Boston area, getting that price requires a detour over to the low price gas zone nearer the gasoline terminal. But it is weird. That’s less than we were paying Rita and Katrina laying waste to US oil and refinery capacity in the Gulf region; and that source of supply hasn’t come back on line.

Why is it so low? I think it’s because both the international regulators and the market over reacted and we are now bathing in petrol sent over by from Europe.

Heat is on at my house. Wholesale natural gas hasn’t rebounded like petrol has. It’s still going for about twice last years prices and some people think we might see a shortage this year. In New England a big slice of our electric power is produced from natural gas. The state has relaxed some environmental protection rules so some older oil based electric plants might be able take a bit of the pressure off the natural gas supply.

But the key fact I draw out of all this is that petrol is a lot more fungible in world markets compared to natural gas. And in the near term US is on it’s own when it comes to natural gas. LNG supply isn’t going to fill the gap – the supply isn’t there and the terminals to accept the supply are don’t exist.

Here’s a bizarre thought. What happens when people to realize that the cheapest most abundant source of fuel this winter is petrol? Most people have no idea how dangerous petrol is.

There are snow flakes outside my window at this very moment.