Proportion of quaxing households Aaron May 22

The next item in the Census challenge is the number of motor vehicles per household, and I thought I’d use this to look at the rate of quaxing in New Zealand cities. By definition households with no motor vehicles must quax, so for each Census area unit I’ve calculated the proportion of such households, for […]

From coal-tit to cannibalistic spiders Eric Crampton May 22

XKCD’s spider explainer has been making the rounds. And one part reminded me of Gordon Tullock.

In 2009, the Back River Wastewater Treatment Plant found themselves dealing with what they called an “extreme spider situation.” An estimated 80 million orb-weaving spiders had colonized the plant, covering every surface with heavy sheets of web.[10] The whole thing is detailed in a fascinating and horrifying article published by the Entomological Society of America.[12]
What was the total force of gravity from all those spiders? First we need their mass; according to a paper titled Sexual Cannibalism in Orb-Weaving Spiders: An Economic Model, it’s about 20 grams for males and several times that for females.[11] So even if you were standing next to the Black River Wastewater Treatment Plant in 2009, the pull of all the spiders inside would still be only 1/50,000,000th that of the Sun.

The paper models when the female spider will eat the male rather than mate as a function of number of potential males around for mating and other food sources. So opportunity costs and relative prices.

Gordon Tullock founded the field of bioeconomics when he observed that the Coal Tit seemed to apply rational choice in its food search, or at least that one could improve on an avian ecologist’s modelling by putting it into that framework. He later founded the journal Bioeconomics.

Here’s Janet Landa’s summary:

Tullock’s (1971) first published bioeconomics paper titled, “The coal tit as a careful shopper”, was published in The American Naturalist, a scientific journal sponsored by The American Society of Naturalists.

According to Tullock, the inspiration for his coal tit article was provided when he read a book by David Lack (1966)—an avian ecologist—in which Lack summarized the work of J. Gibb (1958) on the coal tits’ consumption of eucosmid moth (Ernarmonia conicolana). Because Gibb used a diagram which, to Tullock, looked somewhat like the economist’s demand and supply diagram, this led Tullock to develop Gibb’s idea by explicitly formulating coal tits’ foraging behavior as an economic optimizing problem by comparing the coal tits’ behavior to that of a careful housewife comparison-shopping in the cheapest market: the coal tit would seek its grubs in those areas where the energy cost would be lowest; in other words, coal tits:

… are maximizing the return to their labor in searching out food supplies… . Presumably, they have inherited an efficient pattern of behavior resulting from natural selection which would eliminate inefficient heritable behavior patterns (p. 77).

Tullock (pp. 79–80) ended the article by saying:

It may surprise biologists and certainly will surprise economists to learn that it is possible to use segments of economic theory to explain biological phenomena. Nevertheless, it seems to me that the problems of biologists are difficult enough so that they should seek help wherever it seems to them that their particular competence may be of value. This essay is, then, an effort, to establish a minor link between two fields that at one time were very closely connected, but have grown apart.

Alas, the 1991 spider paper doesn’t cite Tullock.

Next time you see a member of the Swedish Academy who failed to vote for a Tullock Nobel, kick it in the shins for me.


Psychic harms and property rules Eric Crampton May 15

Get your photons off of my lawn!

Here’s Steve Landsburg:

George Johnson of the New York Times writes that:
In a saner world, where science and the law meshed more precisely, a case like Firstenberg v. Monribot would have been dead on arrival in court.

Arthur Firstenberg, you see, is suing his neighbor, Raphaela Monribot, for bombarding him with photons from her iPhone, her WiFi connection, her dimmer switches and her fluorescent bulbs (all as side effects of her ordinary use of these devices). Mr. Firstenberg believes (or claims to believe) that said photons are damaging his health — a belief with essentially no scientific basis.

Mr. Firstenberg requests $1.43 million in damages, so perhaps we should think of this as an exercise in bosonic “ka-ching” theory. The case has gone on for five years, and might be headed to the New Mexico Supreme Court. Estimated court costs so far exceed a quarter of a million.

Psychic harms of this sort have been a problem for a while. How do we decide to allow photonic transgressions that cause psychic harms but not allow other transgressions that (in thought experiments) only cause psychic harms?

Here’s David Friedman’s resolution, from a couple years ago, to a prior Landsburg thought experiment:

More precisely, the property rule under which I have a right to read porn [EC: despite the psychic harm potentially imposed on prudes] and you can only stop me by offering to pay me not to do so produces its result by ignoring the cost my porn reading imposes on you, since, as with the case of risks imposed by careless driving, including that cost requires an unworkable contract between all of the prudes and all of the would-be consumers of porn. The property rule under which you have a right to forbid me, or anyone else, from reading porn, produces its result by ignoring the cost your ban imposes on me, for the same reason. Neither property rule gets the cost/benefit calculation correct, but the former rule is a great deal less expensive to enforce than the latter, which is an argument for it.

What about a liability rule? That is the point at which the subjective nature of the harm comes in. It is true that, from the standpoint of economics, all harm is ultimately subjective—having my arm broken or my car dented would not be a cost under sufficiently bizarre assumptions about my preferences. But some subjective costs are a lot easier to measure externally than others. When I claim damages for my wrecked car, there are market prices out there for repairing or replacing it that provide a court with a reasonable basis for estimating the cost. When I announce that your reading of porn, or oil drilling in a wilderness I never plan to visit, inflicts large psychic harm on me, there is no such basis for checking my claim.

The photon case should use a property right rule where I have the presumptive right to emit photons (though you can pay for abatement), because it’s easy to fake psychic harms from photons and it’s unverifiable.



Rent to income ratio Aaron May 14

Yikes, it’s been too long since I did a Census challenge post. Been busy with work and stuff … The next question is weekly rent for households in rented dwellings. One of the results reported is the median weekly rent. I decided to calculate the ratio of that to median weekly household income (for 2013) […]

Now, subject to increased penalties! Eric Crampton May 14

The NZ Film Censor’s blog helpfully reminds us that the new legislation increasing penalties for possessing objectionable materials is now in force!Their search function tells us that 12 comic books were deemed objectionable from 2000 to 2015, all in 2…

A Whanau Ora puzzle Eric Crampton May 14

I’ve been in Wellington for the better part of a year now. I’ve attended a few different sessions from various Ministries on topics relating to stuff we’re working on or might work on here at the Initiative.

I’ve never properly understood what Whanau Ora, the new(ish) welfare delivery system, was or how it worked. And so I’d ask around a bit at sessions where folks might know; I never got any clear answer on whether it was working out or how it was being evaluated.

The Auditor General also seems puzzled: “It was not easy to describe what it is or what it has achieved.”

Ok, so nobody really knows, and that’s why I only ever got vague answers.

Usually this means that nobody bothered setting up a budget for project evaluation or thought about how to assess outcomes at the outset. You need to build evaluation in at the start.

But the Auditor General also says this:

Nearly a third of the total spending was on administration (including research and evaluation). In my view, Te Puni Kōkiri could have spent a greater proportion of funds on those people – whānau and providers – who Whānau Ora was meant to help.

How do you spend a third of your budget on administration, $42.3 million, including research and evaluation, and still wind up with the Auditor General saying:

We could not get a consistent explanation of the aims of the initiatives in Whānau Ora from the joint agencies or other people that we spoke to. So far, the situation has been unclear and confusing to many of the public entities and whānau. Government agencies need to be able to explain what results are expected – or hoped for – and achieved from spending public funds. Clearly understood aims generally lead to clear accountability and good reporting. Good reporting is particularly important with innovation, because it allows changes to be made when required.

The Auditor General’s right that these kinds of innovative initiatives shouldn’t be abandoned. But it is a bit surprising that a forty million dollar administrative structure couldn’t set up some initial sensible evaluation criteria and methods, with proper reporting follow-through.

That’s the puzzle for me. Not spending anything on evaluation – I can understand that. Spending a pile on admin and evaluation, and getting Auditor General reports like this one – that’s a bit more of a puzzle.


Graph of the Day: How home batteries might benefit houses without solar Will Taylor May 13

I’m pretty excited about the Tesla Powerwall, the home battery that was announced recently. People mostly think about home batteries as being important for solar.  For residential solar,  most of your generation is during the day when you aren’t home, so it gets sold back into the grid and therefore relies on the whatever the […]

Utilitarian abortion Eric Crampton May 09

Bryan Caplan asks:Pro-life utilitarians are very scarce.  A philosophy professor recently told me that he knows of zero pro-life utilitarians in the entire philosophy profession.  This is deeply puzzling.  While I’m n…

CEO Pay Eric Crampton May 07

I reprised this post at a symposium on CEO pay at Otago University on Friday.Here’s my presentation – I had a half-hour to generally survey the lit on why CEOs are paid what they’re paid.  Note that I here overestimated the pay ratio in New Zeala…

Dairy costs? Eric Crampton May 06

No, the external costs of dairying in New Zealand are nowhere near either dairy’s export earnings or dairy’s contribution to GST GDP [my typo, sorry].A peer-reviewed study authored by Massey University scientists has claimed that worst-case scenar…

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