Archive for March, 2009

Stranger Than Fiction vs. Milton Friedman: The Freedom of Surreality

March 31, 2009

The movie ‘Stranger Than Fiction’ was shown on the telly on Sunday. According to my wife, it was supposed to be ‘psychedelic,’ and she did not seem particularly interested in it. My interest, on the other hand, was aroused once I heard that. Often, I find movies more attractive when they are less realistic or when it is obvious that the movie is surreal.

A good movie has some important content; a message, a moral, or a story to tell. When one is free from the bounds of reality, it is much easier to highlight the important content and make it shine. (Many people like subtle stuff; I’m rather slow, however, and like clear, shiny things.) The content in a movie may have everything to do with reality independent of the visual similarity to reality and the logical structure. The same goes for comics, books, paintings, and any form of communication; when a comic assumes its full potential, it is not realistic in a visual sense. With the freedom that follows with surreality, it should be much easier to make a point or tell a story. And, when free from the bounds of reality, anything can happen. It makes it much more interesting.

Here’s where it gets surreal: While I was watching ‘Stranger Than Fiction’ and thinking about the attractiveness of surreality, I came to think of an article on positive economics by Milton Friedman (The Methodology of Positive Economics).  Friedman wrote that a theory would be more important and successful the lesser its assumptions agreed with reality; if a theory with assumptions out of line with reality could successfully explain empirical observations, it showed that the features not agreeing with the assumptions to be unimportant for the observed phenomenon.

[…] to suppose that hypotheses have not only “implications” but also “assumptions” and that the conformity of these “assumptions” to “reality” is a test of the validity of the hypothesis different from or additional to the test by implications. This widely held view is fundamentally wrong and productive of much mischief.  Far from providing an easier means for sifting valid from invalid hypotheses, it only confuses the issue, promotes misunderstanding about the significance of empirical evidence for economic theory, produces a misdirection of much intellectual effort devoted to the development of positive economics, and impedes the attainment of consensus on tentative hypotheses in positive economics.

In so far as a theory can be said to have “assumptions” at all, and in so far as their “realism” can be judged independently of the validity of predictions, the relation between the significance of a theory and the “realism” of its “assumptions” is almost the opposite of that suggested by [positive economics].  Truly important and significant hypotheses will be found to have “assumptions” that are wildly inaccurate descriptive representations of reality, and, in general, the more significant the theory, the more unrealistic the assumptions (in this sense).[reference removed]  The reason is simple.  A hypothesis is important if it “explains” much by little, that is, if it abstracts the common and crucial elements from the mass of complex and detailed circumstances surrounding the phenomena to be explained and permits valid predictions on the basis of them alone.  To be important, therefore, a hypothesis must be descriptively false in its assumptions; it takes account of, and accounts for, none of the many other attendant circumstances, since its very success shows them to be irrelevant for the phenomena to be explained.

To put this point less paradoxically, the relevant question to ask about the “assumptions” of a theory is not whether they are descriptively “realistic,” for they never are, but whether they are sufficiently good approximations for the purpose in hand.  And this question can be answered only by seeing whether the theory works, which means whether it yields sufficiently accurate predictions.  The two supposedly independent tests thus reduce to one test.

Friedman’s argument for ‘surreality’ is not the same as in the ‘Stranger Than Fiction’ example, I know, but it has a similar logical structure. (Or, my mind makes connections between random ideas, which of course may be the case.) Surreality implies freedom, and freedom is powerful both when making movies and constructing economic theory. No surprise there.

Advertisements

Something Out of the Ordinary

March 25, 2009

… happened yesterday. It showed up in my stats:

Stats: Hits for my blogAs you can cleary see, my blog is usually checked out by someone between once and 15 times per day. The pattern has been more or less stable for at least a couple of weeks. (From that, I guess that I have between 5 and 10 more or less steady readers; I wonder who you are. Say hello!) Then, I suddenly get more than 30 hits in one day. What happened?

I got picked up by this weird web page called AlphaInventions.com. It’s a webpage that displays blogs that was recently updated. It shifts every few seconds, but if you see something interesting you can pause it or just click a link on the blog. So, if you’re bored or tired of your common places or simply have a couple of minutes to spare, AlphaInventions shows you something new, all the time. Weird stuff, that invention. Weird, but cool.

Ben Bernanke vs. Thurston Moore, or Macro vs. Noise: The Common Feature of Macroeconomics and Noiserock

March 24, 2009

As odd as it may seem, macroeconomics and noiserock have a common feature. It struck me today while listening to Sonic Youth. (Not that odd; neither me listening to Sonic Youth nor that it struck me that macroeconomics and noiserock have a common feature.)

A musician who uses noise cannot control every soundwave; compare the virtous pianist who’s in full control. Rather, the noise-musician controls a set of parameters that shapes the overall sound picture. The control may be direct or indirect and usually extends to full control over the level.

A macroeconomist, a central banker for example, can in a similar way not control every transaction in an economy. Rather, the macroeconomist controls a set of parameters that ideally shapes the overall structure and development of the economy. The control may be direct or indirect, but the economist does not directly control the size of the economy.

Both the musician and the economist tries to control a perceivable random process through parameters partly directly and partly indirectly under his control.

The big difference, of course, is the potential consequences of their skill and luck. (Some would maybe argue that central banking has little to do with skill, but that’s a different story.) The worst thing that happens when a noise-musician makes bad noise-music is that the audience may get a head ache; head ache is the last thing you worry about when it comes to bad macroeconomic policy.

PS: I could not decide on the best title of this post, so I threw in the kitchen sink; I apologize. Here’s an explanation for those bewildered: Ben Bernanke is the current chairman of the U.S. Federal Reserve ; Sonic Youth is one of the best noise-rock bands out there (check it out), and it has Thurston Moore on guitar and noise.

The Visible Human Project

March 24, 2009

Just a quick note to make those unaware aware of The Visible Human Project. They’ve sliced a frozen body up in very thin pieces and photographed each piece. Below is a section through the chest; you can see the heart, lungs, and the spinal column among other things. On the homepage there is an animated ‘travel’ through the body from head to toe.

Thorax from The Visible Human ProjectOf course, there are ethical questions surrounding using data from the project in research. The body belonged to a prisoner given the death penalty. Questions such as Should society, and more specific, should science, benefit from killing prisoners? If one is against the death penalty, is research based on The Visible Human Project still ok? (See Norwegian medical magazine here for discussion.)

Skyscrapers Are Green

March 23, 2009

Bringing down carbon emissions requires us to drive less, and Americans particularly so. A couple of economists studied the carbon footprint from living in different areas in the U.S. (see story here):

In almost every metropolitan area, we found the central city residents emitted less carbon than the suburban counterparts. In New York and San Francisco, the average urban family emits more than two tons less carbon annually because it drives less. In Nashville, the city-suburb carbon gap due to driving is more than three tons. After all, density is the defining characteristic of cities. All that closeness means that people need to travel shorter distances, and that shows up clearly in the data.

In an extended account of the study, Gleaser (the author) highlights some of the paradoxes in true environmentalism:

[…] if you want to be good to the environment, stay away from it. Move to high-rise apartments surrounded by plenty of concrete. Americans who settle in leafy, low-density suburbs will leave a significantly deeper carbon footprint, it turns out, than Americans who live cheek by jowl in urban towers. And a second paradox follows from the first. When environmentalists resist new construction in their dense but environmentally friendly cities, they inadvertently ensure that it will take place somewhere else—somewhere with higher carbon emissions. Much local environmentalism, in short, is bad for the environment.

It’s hardly surprising that living in cities requires less driving and less heating. It also seem plausible that constructing new houses, with all the wires and pipes that needs to be connected, should be easier and greener in densly populated areas than in the suburbs and in the country-side.

In the article, Gleaser claims that it is paradoxical that staying away from the environment is good for it. Can someone please explain to me the paradox in that? If a piece of environment is to be kept in a pristine or anything close to a natural state, of couse you have to stay away from it.

Hat-tip: Freakonomics

Economics Is Hard

March 19, 2009

In an old post on Freakonomics that discusses the Coase Theorem, Steven Levitt, the great economist, writes:

The basic idea of the Coase Theorem is that no matter who is assigned property rights, as long as transaction costs are not too high, the efficient outcome will be achieved.

That’s wrong, as far as I know. Well, at least, Deirdre McCloskey, who seem to know her stuff better than most, writes in her little gem Economical Writing:

“[T]he Coase Theorem” [that is] “the proposition that property rigths matter to allocation in the case of high transaction costs” (which, incidentally, is the correct statement of the theorem, widely misunderstood in economics) [p. 60, 2nd edition].

The quote is taken out of context, which is a discussion of the use of Capitalization, but that’s beside the point. Now, I looked the theorem up in the book I learned it from back in the days (‘Environmental Economics – In Theory and Practice’ by Hanley, Shogren, and White, 1997), and it was wrongly stated there as well:

The so-called Coase theorem posits that disputing parties will work out a private agreement that is Pareto efficient [that is, no-one can be made better off without making someone else worse off], regardless of the party to whom unilateral property rights to the non-market asset are assigned initially [p. 25].

Both Levitt and my text book are right, of course; property rights do not matter to efficiency when transaction costs are ignored. They are always present, however, and that’s were Coase put his emphasis, I think; when transaction costs are substantial, property rights matter. I should look up Coase’s original formulation and find out for myself, I know. I’m lazy, though, maybe some other time. I did google it, however, and every single explanation I found among the top hits got it the wrong way.

Economics is hard. Or confusing, maybe.

CompuTATION time revisited

March 18, 2009

I must have been tired on Saturday. What the heck is computer time anyway? The time your kids are allowed at the computer each day? Anyway, I was wrong about the necessary time to solve my problem on a coarser grid; it would take my computer something like 20 hours to complete the task if left alone (I tend to surf the internet, reading blogs for example, while my computer computes, slowing it down). 20 hours is unacceptable. I found out, however, that my solutions were linear and that I only needed to solve the problem numerically in four nodes. That’s done less than 5 seconds! That’s what I call progress.

Computer Time

March 15, 2009

I just calculated that if I were to solve the problem I’m working on numerically on the finest grid possible, it would take my poor laptop more than a thousand years to finish the job! That is, 0.537594 seconds per node on more than 6.8*10^11 nodes! (Ugly notation, I know, this ‘quickpress’ editor doesn’t impress.) A thousand years; that’s depressing. Less than 10% of the output would be interesting to me, however, so, by making my routine take care of that, I’m down to only a hundred years! Hm. I’ll settle for a coarser grid, I guess; I’ll be down to a little more than 150 000 nodes, which my computer should be able to take care of in approximately 20 minutes.

I could buy a new computer instead. The one I have is almost 4 years and needs replacement anyway. I doubt, however, that computers have reached the state where they can make a hundred years go away yet, but maybe they can prevent me from posting nonsense in the middle of the night?

A Mathematician’s Apology by G.H. Hardy

March 11, 2009

I just finished G.H. Hardy’s ‘A Mathematician’s Apology,’ and I intend to jot down some thoughts on it. I’ve been wanting to read this book for quite a while (I’ve had it for over a year) as it has been mentioned in several other books and texts that I’ve read earlier. From what I’d read about it beforehand, I expected some sort of philosophical discussion and understanding of mathematics. I also expected a mathematician’s position in relation to some fundamental philosophical questions like religiousness. Hardy do discuss mathematics in what you may call philosophical way. I was, however, disappointed.

Hardy's Apology

Hardy was a successful mathematician, working as a professor at both Cambridge and Oxford from circa 1900 until his death in 1947. One of his greatest achievements was to prove that the Riemann zeta function has infinitly many roots with real part equal to one half. According to himself, however, was his most important contribution (whether to mathematics or in general I’m not sure, but he probably meant both) the discovery of the Indian mathematical genius Ramanujan.

Hardy was a peculiar man. He had an intense interest in cricket, for example. Within a week of his death, he allegedly said to his sister: ‘If I knew that I was going to die today, I think I should still want to hear the cricket scores.’ Among other peculiarities was his games with God, which become even more peculiar since he claimed not to believe in God. One a trip abroad, he once sent a postcard to a colleague claiming that he had proven the Riemann hypothesis. The idea was that God would not let Hardy’s boat on the return journey sink and, according to some accounts, allow him the same, mytic fame Fermat achieved with his last theorem. Other accounts claims that the idea was that God would not let such a discovery as the solution to the Riemann hypothesis die with him.

I cannot help but to include this list of New Year’s resolutions Hardy once sent to a friend. It shows both ambition and humour. I am sure Hardy meant every word:
1. To prove the Riemann hypothesis,
2. To make a brilliant play in a crucial cricket match,
3. To prove the nonexistence of God,
4. To be the first man atop Mount Everest,
5. To be proclaimed the first president of the U.S.S.R., Great Britain, and Germany, and
6. To murder Mussolini.

Now, the book. First of all, I didn’t like the foreword by C.P. Snow. The foreword was not part of the original book, but was added long after Hardy’s death. It is much too long, particularly for a short book like the Apology, and it draws an untimely picture of Hardy in particular, and of early 20th century British academics in general, as shy, helpless brainies unable to deal with the real world. The only interesting parts in the foreword are the biographical facts about Hardy’s life.

The Apology was published in 1940. By then, Hardy had become a bitter, old man, deprived of his powers as an imaginative mathematician. Obviously, mathematics was one of two truly important things to him, the second being cricket. Feeling that his life is essentially over, he finds it necessary to write the Apology. The book seem to serve as some sort of justification of his life as a mathematician, and, as he claims some sort of generality of his arguments, justification of all mathematicians and of mathematics itself.

I found the topic of the book interesting enough; a discussion of why mathematics is worthwhile; mathematics, the only enterprise of man where absolute truths exist. I found Hardy’s conclusion a bit discouraging, however; I’ve been a student of mathematics myself, and have caugth a glimpse of true, mathematical beauty. I’ve been a fool, it seems, to think there’s something more to it. That depends, however, on my acceptance of Hardy’s position in relation to a range of issues. In most cases, I don’t.

First of all, I don’t like his tendency to claim his position to be common to all pure mathematicians. He may be right, but I won’t accept that just like that. The Apology is generally acclaimed as one of the best insights into the mind of a working mathematician available to laymen, and that may be an indication that Hardy is indeed talking for most mathematicians. Anyway, in his very first paragraph (§1), he claims that exposition and criticism is work for second-rate minds. I wholeheartedly disagree, and I am actually a bit offended by that. Hardy’s problem is his limited understanding of exposition and criticism which is revealed in the Apology. (I won’t argue this case, but I believe any experienced writer would agree that the exposition of the Apology has room for considerably improvement). How can he claim a mind to be second-rate when he does not understand what it does or how it works?

G.H. HardyHowever, the following passage from §2 I agree with and will try to carry with me in my pursuit of a doctoral degree:

Good work is not done by ‘humble’ men. It is one of the first duties of a professor […] to exaggerate a little both the importance of his subject and his own importance in it. […] He must shut his eyes a little and think a little more of his subject and himsleft than they deserve.

In the following paragraph (§3), Hardy essentially brings forth the one reason he finds sufficient to justify his life’s work as a mathematician; he’s good at it. Moreover, anyone who is really good at something should ‘make almost any sacrifice in order to cultivate’ his talent. Hardy also claims that very few men are able to do something rather well. I can accept Hardy’s personal justification to pursue his talent. I cannot, however, accept it as a general thesis; many talents aren’t desirable, neither personally nor socially. And, while it is tempting to think that few people have extraordinary talents (it seems plausible, for example, from a probabilistic position), all have the urge to survive embedded in their genes. Given the extreme complexity of the human brain, who knows what other talents lies hidden? Maybe it is more about discovering a talent than having it.

Towards the end of §6, Hardy again demonstrates his condemnation of rhetoric;  he seem to think that content, or substance, doesn’t depend on form. That is simply not true. It may be that mathematicians in particular, and natural scientists in general, believe that they deal with substance only. However, substance and form are two sides of the same coin, and substance is what is read into a certain form. If there’s a problem with the form, or rhetoric, there’s a problem with the substance.

In §22, Hardy writes that he believes mathematical reality to lie outside us, and our (that is, mathematicians, I presume) function is to observe it. I’ve already written that mathematicis is the only scientific enterprise that deals with absolute truths; truths outside ourselves. (Think prime numbers.) Any mathematical discovery, however, depend on axioms, and axioms depend on us (mathematicians, that is). Axioms are supposed to be ‘natural,’ but as long as mathematicians seem to differ in opinion on the ‘intuitivity’ of axioms, I am skeptic. An example of such disagreement may be the Parallel Postulate, which has been subject to centuries of debate.

In §24, Hardy argues that mathematical reality lies outside us:

A chair or a star is not in the least like what it seem to be; the more we think of it, the fuzzier its outlines become in the haze of sensation which surrounds it; but ‘2’or ‘317’ has nothing to do with sensation, and its properties stand out the more clearly the more closely we scrutinize it. […] Pure mathematics […] seems to me a rock on which all idealism founders: 317 is a prime, not because we think so, or because our minds are shaped in one way rather than another, but because it is so, because mathematical reality is built that way.

I have sympathy with the prime number argument; I cannot imagine prime numbers being anything else than prime numbers. So, with my limited knowledge of mathematics, I may agree that some of what Hardy calls mathematical reality, like prime numbers, lies outside us. I still have problems with the axioms, though, but in the interest of time I’ll leave that discussion for now.

My ‘review’ is far too long already. I need, however, to discuss one more claim Hardy makes to complete my discussion of the Apology. Hardy makes a clear distinction between ‘real’ mathematics and ‘trivial’ mathematics. With trivial, he means all type of applied and school mathematics. This may seem to be a clear distinction, and it is crucial to Hardy’s final conclusion. Hardy goes on to claim that real mathematics is not harmful in any way, as long as it is ‘useless.’ And with useless, he means not applicable to real world problems. There is no clear distinction, however, between real and applied mathematics, and while it may be difficult to realize the applied potential in pure mathematical discoveries, history has shown it otherwise. Numerous results from real mathematics has proved useful in applications. Crown examples are the role of prime numbers in cryptography and Einstein’s theory of relativity. And as long as there is no clear distinction between pure mathematics and applied mathematics, Hardy cannot escape the truth that mathematics as a whole is useful and, more severe to his conclusion, may be harmful.

To Hardy’s defence, it may be asserted that he lived in a different time than ours, and, if they ever were, that his views are probably no longer are representative of mathematicians in general. Indeed, I do hope that present day mathematicians are more in contact with reality than what Hardy seemed, and realize both the potential value and danger in pure mathematics.

Hardy’s conclusion, then, is that mathematics is nothing more but a creative art, and that his achievements

[…] differs in degree only, and not in kind, from that of the creations of the great mathematicians, or of any of the other artists, great or small, who have left some kind of memorial behind them.

It seems clear that Hardy, despite all his devotion and appreciation of it, reduces mathematics to an art, and resembles great mathematicians like Hilbert and Abel with other great artists like Mozart and Picasso . Not that I don’t think highly of art. Art, to me, is a product of the human mind; meant to please or provoke; meant to mean something; meant to influence someone; and, not the least, a product of an urge to create. Art is a sign of prosperity and abundance, not necessarily a necessity. Pure mathematics, however, is different; it is an expedition into the absolute; investigating and observing logic; not meant to please or provoke, but a necessity to progress. It may resemble art, nonetheless, depending on creativity and inspiration, but still being different, and, in my eyes, more important; while any artist or may be much more important to any one individual, the great mathematicians are much more important to the human kind.

Those interested can download the book for free (luckily, without the foreword by C.P. Snow) and make up their own mind.

Responsible Fishing

March 10, 2009

A few days ago, I posted a graph of world fish production from The Economist website. Along with it, I quoted a comment from a reader suggesting that among others, Norwegians were to blame for irresponsible fishing activities. The reader may think of Norwegian trawlers, or trawlers owned by Norwegians for that matter, that fishes in foreign or international waters. While it may be (or most likely is) true that Norwegians fish irresponsibly elsewhere, Norway are at least at the top when it comes to the management of marine resources in domestic waters. The World Wildlife Fund, together with the University of British Columbia Fisheries Center, Canada, has recently issued a report that has evaluated the top 53 fishing nations in the world’s compliance with the United Nations’ Code of Conduct for Responsible Fisheries. There is room for considerable improvement, however, also in Norway.

Overall compliance with the Code is dismal: not one country out of the 53 achieves a “good” score of 70% or more. Only six countries (11%) have overall compliance scores whose confidence limits overlap 60% (Norway, USA, Canada, Australia, Iceland, Namibia). This means that, twelve years after the Code of Conduct was agreed, there is a great deal of room for improvement in compliance even among those countries at the top end of the rankings. At the lower end, the alarming finding is that 28 countries (53%) had ‘fail grades’ of less than 40% (Peru, Poland, India, Ghana, Taiwan, Latvia, Philippines, Brazil, Argentina, Morocco, Pakistan, Russia, Senegal, Ecuador, Indonesia, Iran, Thailand, Ukraine, Sri Lanka, Viet Nam, Turkey, Bangladesh, Egypt, Yemen, Nigeria, Angola, Myanmar, North Korea).

Related posts:

Iceland in Crisis

March 9, 2009

Since Iceland is one of Norway’s neighbors and since my supervisor is Icelandic, I found this article about the financial mess on Iceland quite interesting. It’s called ‘Wall Street on the Tundra’ (another title I don’t quite understand; to call Iceland Wall Street is, well, strange, I think, and while tundra may be exotic, what does it have to do with the financial trouble?), and the introductory paragraph goes like this:

Iceland’s de facto bankruptcy—its currency (the krona) is kaput, its debt is 850 percent of G.D.P., its people are hoarding food and cash and blowing up their new Range Rovers for the insurance—resulted from a stunning collective madness. What led a tiny fishing nation, population 300,000, to decide, around 2003, to re-invent itself as a global financial power? In Reykjavík, where men are men, and the women seem to have completely given up on them, the author follows the peculiarly Icelandic logic behind the meltdown.

Among the more amusing paragraphs, you’ll find the following caricature of how Icelandic banks operated:

You have a dog, and I have a cat. We agree that they are each worth a billion dollars. You sell me the dog for a billion, and I sell you the cat for a billion. Now we are no longer pet owners, but Icelandic banks, with a billion dollars in new assets.

The author (Michael Lewis) also comes up with an interesting theory of why so few seemed to foresee the global economic downturn:

One of the hidden causes of the current global financial crisis is that the people who saw it coming had more to gain from it by taking short positions than they did by trying to publicize the problem.

Hat-tip: Freakonomics

UPDATE: My Icelandic supervisor made me aware of a more informative and analytic story on the Iceland crisis from the Wall Street Journal.

Do Macroeconomics Need a Revolution?

March 9, 2009

The environmental crisis has lead to stark criticism of economics from environmentalists; here is my latest post on the voodoo debate. The financial, or rather, economic, crisis now leads economists to attack macroeconomists. Freakonomics discusses a recent research paper that goes far to suggest that time’s up for macroeconomics as we know it and that a regime shift is needed. As far as I can tell, the situation has all the signs of a scientific revolution, but those things usually takes a generation or so.

Justin Wolfers writes, under the charming title ‘More Navel-Gazing from Academic Economists’ (which I don’t get, by the way, first of all, Who aren’t navel-gazing? and second, Do he suggest that the discussion is irrelevant outside academic economics? third, Aren’t academic economists supposed to be occupied with academic economics, and thus be, to a certain extent, navel-gazing?), that macroeconomists write to each other, pursuing formal elegance (I wanted to write eloquence, but became uncertain; I’ve now decided it would fit as a metaphor; anyway) instead of empirical knowledge.

The claim is that academic macroeconomists have become mired in a particularly fruitless equilibrium, in which each is engaged in the search for ever-greater levels of formal elegance, at the expense of empirical relevance. There’s definitely something to this.

Mr. Wolfers is optimistic though:

Despite this observation, I don’t share the gloom of the naysayers, but my optimism comes from looking beyond macro. As a whole, the economics profession has become more empirically grounded.

The post on Freakonomics links to further discussions for those interested.

More on World Fish Production

March 6, 2009

I just, presumably somewhat delayed, received the latest issue of Marine Resource Economics (Vol. 23, No. 4, 2008) . It’s a special issue on aquaculture (fish farming). There I found an interesting graph that relates to my earlier post on world fish production. The introductory piece (‘Aquaculture – Opportunities and Challenges,’ written by Asche, Guttormsen, and Tveteras) features a graph of world fish production from 1970 to 2006:

World Fish Production 1970-2006

In contrast to the somewhat confusing graph from The Economist (see earlier post), it is clear from this graph that fisheries has leveled off since the late eigthies, while there is steady growth in farmed fish production. According to the article, farmed fish represented half of the fish produced for human consumption in 2008.

Since 1970, world fish productin has on average increased with roughly 3.5% per year and, from the graph, shows no sign of leveling off. To the contrary, farmed fish production has increased with approximately 12.5% per year since 1990! Indeed, aquaculture has been ‘the world’s fastes growing animal-based food sector during the last decades,’ according to the article authors. In comparison, the current global population growth rate is approximately 1.2% (see U.S. Census Bureau), and is expected to fall in the next forty years. Presumably, more and more people have started to, and will in the future, eat more fish.

Not all wild fish caught is used as food for humans, however; a substanial part of it goes into the production of farmed fish, for example. Further, more and more people eat more and more as developing countries moves out of poverty; world food consumption by humans will likely rise faster than the population grows. I’m not sure the authors have thought of these things, but they are anyhow optimistic on behalf of aquaculture’s growth prospects:

Given the status of global fisheries, with most large fish stocks being fully exploited or over-exploited, aquaculture production must increase in order to maintain or increase the global seafood supply per capita. Fortunately, the aquaculture sector seems well positioned to succeed in this respect.

Related posts:

1 000 000 000 000

March 5, 2009

How much is a trillion? Jim asks in relation to the proposed U.S. deficits in the next few years. (Jim is one of my favourite economists, or should I say professor.) The short (and pedantic) answer would be the title of this post. Another is a million million. Jim’s may be better (for Americans, at least):

A trillion dollars is about the total amount collected in income taxes by the U.S. federal government in fiscal year 2006– $1.04 trillion, if you’re curious to use the exact number. That gives me a simple rule of thumb for personalizing these numbers. If I want to know what an additional trillion dollars in government borrowing or spending will mean for me, I just imagine what it would be like to pay twice as much in federal income taxes for one year.

The comments on Jim’s Econbrowser yields other amusing ways to imagine a trillion:

A billion dollars is a stack of $1000 dollar bills 358 feet high. A trillion dollars is a stack of $1000 bills 67.9 miles high!

Another way to look at it is that a business that was started on the day Jesus was born, and lost one million dollars EVERY single day since then, would still not have lost $1 trillion.

If you earned 1 dollar for every second you would have:
$1 million after 2 months
$1 billion after 32 years
$1 trillion after 32 000 years. 32 thousand years!

Here’s an appropriate quote from physicist Richard Feynman: “There are 10^11 stars in the galaxy. That used to be a huge number. But it’s only a hundred billion. It’s less than the national deficit! We used to call them astronomical numbers. Now we should call them economical numbers.”

To be sure, the comments has a lot of interesting content as well.

World Fish Production

March 4, 2009

Since I’m into fisheries economics, I found this chart from The Economist interesting. World fish production was 143.6 million tonnes in 2006, the highest ever recorded. Something doesn’t add up, however. According to the accompanying story, the wild fish catch levels off while the farmed portion of fish eaten by people is 47% and assumed to increase. The graph shows that farmed fish is leveling off. Also, they write that the catch in 2006 was 92 million tonnes, which obviously corresponds to the blue part of the 2006 column; they switched the colors of the columns.

Some of the comments to the story are interesting too. Derek L, for example, writes:

We’re all in this. There is no use blaming the Asians, the Norwegians, or the Spanish. Sure they happen to be the three biggest offenders, but anyone who buys anything but line caught wild fish should be slapped hard upside the dead for every purchase.

Not surprisingly, he’s a vegetarian. While I agree that industrial methods in fishing has problems, I also think that there are solutions and that we need to pursue them. Managed appropriately, I believe fish can help alleviate some of the problems presented by a growing population and declining biodiversity.

World Fish Production

UPDATE: If you’re interested in a fuller picture of world fish production in a longer time perspective, check out my follow up posts: