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Linklist: April 19, 2012

Via Tyler Cowan, Foxnews: Disney's ‘NextGen’ plan is expected cut wait times for rides and more:

"Details of the plan emerged in February 2011 when Walt Disney Parks and Resorts Chairman Tom Staggs announced some major changes at an investors' conference.

“Guests will be able to reserve times for their favorite attractions and character interactions…secure seats at our shows and spectaculars…make dining reservations…and pre-book many other favorite guest experiences -- all before even leaving their house," Staggs said. 

Since then, Disney has remained quiet about the project -- even its existence. 

“I can’t confirm nor deny it,” said Disney representative Marilyn Waters when asked her about the NextGen project."

A gravity-ish model of the brain - KurzweilAI reports: A statistical model of the network of connections between brain regions :

"Researchers at the University of Cambridge have developed a simple mathematical model of the brain which provides a remarkably complete statistical account of the complex web of connections between various brain regions.

The brain shares a pattern of connections that is similar to other complex networks such as social networks and the Web. However, until now, it was not known what rules were involved in the formation of the human brain network.

The scientists, from the Behavioral and Clinical Neuroscience Institute in the University of Cambridge Department of Psychiatry, and the National Institute of Mental Health in the U.S., discovered that the network can be modeled as a result of just two different competing factors: a distance penalty based on the cost of maintaining long-range connections between various brain regions, and a second term modeling the preference for links between regions sharing similar input."


If I understand correctly, many macroeconomists believe that the current economic troubles are due to a decline in aggregate demand for goods. (Or an excess of demand for jobs on the part of labor, or a contraction in the supply of jobs for labor, leading to unemployment, and therefore not enough spending).

In queueing theory, we have a cumulative input-output diagram. When the inputs at a given time exceed the amount that can be served (or output), a queue results, and there is a loss in terms of delay. This wasted time can never be recovered.

Future wasted time can be prevented if we align supply and demand, so the number of people arriving at the back of the queue exactly equals the number of people that can be served at the front of the queue (and we have no standing queue at the beginning of this process). We exactly use the available productive capacity, with no over-production or under-production. Over-production, or attempted over-production results in queueing. Under-production is people sitting on the sidelines when the capital is capable of producing more. In either case there is wasted labor (either queuing or people on the sidelines).

We can map the economy as a racetrack (see movie below). Upon passing the some point, let's say the South-East "corner" of the racetrack, and call that point "Go", money is exchanged. People are paid for their work. Flow (vehicles per hour) past a point is the analog to GDP, and is the measure of the productivity of the system.

The economy is maximally productive when vehicles circulate on the road as fast as possible. We can increase output by increasing labor productivity (the speed at which drivers drive, and their reaction time when someone ahead slows down), thereby reducing headways. Racecar drivers are more productive that normal drivers, because they have greater skill, but they might be troublesome if they increase the risk of crash. We can increase output by adding labor (more drivers) if we have increased productivity, or if we have remaining under-utilized productive capacity. We can increase output through technological advances, like driver-assistive vehicles that allow cars to follow more closely.

We can also increase productivity by adding capacity to the road if there are more vehicles that want to use the road than currently can. Reinvesting in the road, rather than paying workers more now, makes sense for an economy that expects to grow either due to a larger population (more cars) or higher productivity (drivers who can driver faster and closer at the same safety level). We will lose long term productivity if we allow capital (the road) to wear out without renewal, preservation, replacement, repair, or rehabilitation.

The risk of over-heating is a crash (literally), two cars collide, slowing down the road for everyone else, since productivity drops, fewer people get paid, etc. Driving is a trade-off between value of time (I want to driver faster to save time) and value of life (I want to drive slower to decrease the likelihood of death from crash). Labor is a trade-off between production and consumption. If everyone produces and no-one consumes, no-one can pay the producer. It is our patriotic duty to consume, even if that contravenes the Protestant work-ethic.

A central planner could come in and tell the racetrack to hire more workers (drivers), induce the firm to hire more workers (by lowering some cost of hiring such as taxes or regulation or required benefits), seize the firm and hire more workers itself, or open up a bypass to the firm and hire these workers itself. This would increase revenue in the pockets of consumers, and consumer spending, assuming people thought this change was permanent.

In this story, the deadweight loss of unemployment would be eliminated in the short run.

The problem is the long run dynamics. In the long run, people tire of the good that is being produced, or its market saturates, and consume less of it. Then unless the firm retools to match demand, it has to lower employment. A new firm, with a new bypass, could come in, create a new good people are interested in, hire workers, and so on. These "Gales of Creative Destruction" sweep the old firm/economy/racetrack away.

The real world is comprised of millions of bypasses (firms) which transform labor and capital into goods, and labor itself is not homogeneous, each worker has her own path from consumption to production.

The question is then empirical, whether a short-term "stimulus" by hiring more workers and eliminating that dead-weight loss, but also eliminating incentives to invent and create by reducing the risk of unemployment, outweighs the incentive effects.

Ideally the system is self-correcting. A capitalist seeing unemployed labor which can be hired inexpensively to produce some good

We then get to the empirical question of whether there is excess productive labor sitting on the sidelines in the real US economy (e.g. as indicated by a relatively high unemployment rate), or whether those excess workers are just unproductive or negatively productive, i.e. drivers who would just gum up the works for other drivers (because, to extend the analogy their driving skills are sufficiently poor to increase the likelihood of crashes, etc.). I expect the first is true, that is, there is excess productive labor, and the imperfections of the economy, stickiness of labor, regulation, mis-information, animal spirits, etc. are leading to less productivity than the US, and certainly the world, might achieve given existing technologies and labor pools.

That said, whether just dumping money into the system will lead to the economy actually moving faster I think is still an open question. That money comes from somewhere, either devaluing the currency, or future earnings. But if productivity creates wealth, and increasing the size of the active workforce increases output, output that would otherwise be lost forever (just as when a plane takes off, it can no longer fill a vacant seat), it would seem to make sense to borrow from the hopefully wealthier future to increase output now to fulfill our hopes that the future will be wealthier.

"Who should do the borrowing?", the central planner or millions of individual planners, is also an empirical question. There are always tradeoffs between economies of scale and span of control. There is also the information problem (Hayek's Fatal Conceit) about directing the money, as well as the belief problem (Keynes' Animal Spirits) which suggest that if everyone believes things are going well, they will invest, and if they believe things are going poorly, they will disinvest, fulfilling their own prophecy. If capital is indeed sitting on the sidelines because people's beliefs about other people's beliefs are negative, the confidence game that is the economy will come to a screeching halt. This self-fulfilling prophecy phenomenon may require a possibly counter-intuitive, contra-cyclical contrarian to set right, the scale of which may need to be central (and large) to be effective. This empirical question is unresolvable (and following Popper, all hypotheses are unprovable anyway), because we have only one economy, and are thus running only one experiment, there is no control. Econometrics could come in and use a panel data set of many historical events over many places and tell us some things, but I believe any conclusions from these kinds of statistical models will be contentious rather than consensus.

Caveat. I know this is a grossly over-simplified model, but hopefully it elucidates some things.

See also: The Transportationist: Quantity theory of money and fundamental equation of traffic

From the NY Times: Disney Tackles Major Theme Park Problem: Lines

Disney isn't reducing lines (through congestion or reservation pricing) much, (there is the occasional added capacity), mainly it just sends entertainment out. Maybe we should have jesters at long traffic lights to entertain drivers.

147 Vehicles and Pedestrians in 4:18


My favorite five-way intersection (Franklin Avenue/East River Road/27th) has now been signalized for over a month. The video was taken on Oct 11 in the late afternoon (I apologize for the poor angle, but I wanted the same position as before as much as possible, unfortunately the sun did not cooperate (or alternatively the clouds did not obscure the sun), also I reduced the resolution for the Web). Other differences to note are that school is now in session.

The intersection was roughly at capacity (as can be seen), in that most conflicting movements were fully served with approaching cars, though I suspect throughput could be a bit higher.

We observe a throughput of about 1948 vehicles per hour (based on my estimate of 147 vehicles and pedestrians and bicyclists in 4:18), which compares favorable with the more chaotic 5-way stop during reconstruction which served about 1600. There seems a long period of lost time that could perhaps be used to improve capacity/lower delay.

The main difference is the extra capacity due to more systematic parallel movements (yielding more than one critical point). Notice the pedestrians just past the 4 minute mark are still quite confused as to whether to go or not.

As a user, the pedestrian timing is still terrible, and I just go whether or not I have the signal, so long as I am unlikely to be flattened like a pancake by oncoming cars.

This movie was taken by me, with my iPhone, on the way home from work on August 19, 2010 at 5:22 pm. The five-way stop controlled intersection (Franklin Ave/ East River Road / 27th Ave) seems to have a maximum throughput just over 1600 vehicles per hour. Most of the movements are saturated during the peak. This intersection has been blogged about before.

The downside for a stop controlled intersection is that the allocation of time across legs is "unfair", i.e. drivers are supposed to take turns (yield to the right). Thus a leg which is just saturated will get just as much access to the critical points of the intersection as a leg that is supersaturated, resulting in much higher delays on the supersaturated movements. I did not measure delay, but it is longer on this day for travelers moving WB on Franklin Ave.

There are several other points to note.

(1) Drivers do not all know the "yield to the right" rule.

(2) This results in "negotiations" between drivers about who should go. Less aggressive drivers clearly lose, but eventually go.

(3) This generally increases throughput compared to obeying rules (do not start until the intersection is cleared is violated, to the benefit of throughput).

(4) The intersection is confusing but safe. Any crashes during peak times would be very low speed.

(5) It is more confusing because of the construction.

(6) The intersection was configured with operating signals in September 2010.

The Guardian posts an article: Bribe your way to the front of the queue in Britain and India

Apparently first class passengers in the UK get undeserved perks from their government much like those in the US. See previous post. In this case it is queue-jumping the immigration line rather than queue jumping the security line. I don't know which is worse. Both are appallingly inequitable and should not be supported by government.

The other thing to note is that this is quite un-British, where the people (or at least the non-elites) are taught how to queue. Queueing is something the British excel at due to their extensive practice in the matter, it would be a shame to see them lose their competitive advantage in this arena.

David Levinson

Network Reliability in Practice

Evolving Transportation Networks

Place and Plexus

The Transportation Experience

Access to Destinations

Assessing the Benefits and Costs of Intelligent Transportation Systems

Financing Transportation Networks

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