Archive for December, 2012

An Overview of Empirical Analysis of Behavior of Fishermen Facing New Regulations

December 17, 2012

Some time ago, I published a review article in Environmental Economics (2012, volume 3, issue 2). It is based on a lecture I gave as part of my dissertation defence in 2010, and the title is derived from the topic I was given for the lecture. When I prepared my lecture, I wrote up my notes in article format. Later, I spent some time polishing and preparing the article for submission. Oddities intervened, and the submission was put on hold for a substantial amount of time. But, I came out in the end, and I am happy about it. Here is the abstract:

Environmental EconomicsThis paper reviews the empirical literature on fishermen’s behavior under changing regulations. The review is not exhaustive; instead, the work focuses on the historical development of empirics in fisheries economics and the parallel development of fisheries regulations. While historic parallels are difficult to observe for later developments, recent empirical analysis of fishermen’s behavior illustrates the breadth and interdisciplinary nature of current empirical fisheries economic research. It merges biology, economics, and social science with statistical, mathematical, and rhetorical methods. The author hopes to capture some of the interdisciplinary interplay in the review.

Daniel Kahneman on the Unpredictable Luck Involved in Hitler’s Rise to Power

December 5, 2012

I am reading what someone in the local newspaper hailed as last year’s most important book; Daniel Kahneman’s Thinking, Fast and Slow (and for the record, I started on it before the newspaper brought it up, but progress is as always painfully slow). It is great, really great (and not a footnote in sight!), penetrating deep in to the human condition. It might well be last year’s most important book, indeed. In an odd twist, he ends up discussing the role of unpredictable luck, or rather unluck, in how Hitler came to be what he became. The discussion came up in a chapter entitled The Illusion of Validity, which opening paragraph is worth quoting:

System 1 [thinking fast] is designed to jump to conclusions from little evidence–and it is not designed to know the size of its jumps. Because of WYSIATI [What You See Is All There Is, a central concept in Kahneman’s work], only the evidence at hand counts. Because of overconfidence by coherence, the subjective confidence we have in our opinions reflects the coherence of the story that System 1 and System 2 [thinking slow] have constructed. The amount of evidence and its quality do not count for much, because poor evidence can make a very good story. For some of our most important beliefs we have no evidence at all, except that people we love and trust hold these beliefs. Considering how little we know, the confidence we have in our beliefs is preposterous–and it is also essential [p. 209*].

I am not sure what Kahneman has in mind with the last remark that confidence in our beliefs is essential. He did not return to it in the chapter, but perhaps he returns to it later in the book. What he do discuss in the chapter are how humans think they understand the past and why things happened while pure chance, unpredictable luck, is not an essential or sufficient part of the understanding.

The often-used image of the “march of history” implies order and direction. Marches, unlike strolls or walks, are not random. We think that we should be able to explain the past by focusing on either large social movements and cultural and technological developments or the intentions and abilities of a few great men. The idea that large historical events are determined by luck is profoundly shocking, although it is demonstrably true. It is hard to think of the history of the twentieth century, including its large social movements, without bringing in the role of Hitler, Stalin, and Mao Zedong. But there was a moment in time, just before an egg was fertilized, when there was a fifty-fifty chance that the embryo that became Hitler could have been female. Compounding the three events, there was a probability of one-eighth of a twentieth century without any of the three great villains and it is impossible to argue that history would have been roughly the same in their absence. The fertilization of these three eggs had momentous consequences, and it makes a joke of the idea that long-term developments are predictable [p. 218].

*Page numbers refer to the first British edition (Allen Lane).

Do Species Interactions and Stochasticity Matter to Optimal Management of Multispecies Fisheries?

December 4, 2012

Earlier this year, the research team I am a part of (the BMAME-team) published a chapter in the book Global Progress in Ecosystem-Based Fisheries Management, edited by G. H. Kruse and others. The chapter has the winding title Do Species Interactions and Stochasticity Matter to Optimal Management of Multispecies Fisheries?, and is authored by Diwakar Poudel, Leif K. Sandal, Stein I. Steinshamn, and myself. The answer to the question in the title is a resounding It Depends. The abstract:

GlobalProgressFrontMultispecies fisheries management looks at a bigger picture in addressing the long-term consequences of present decisions. This implies an ecosystem management that includes a number of species and their physical, biological, and economic interactions. These interactions make the growth of resources stochastic and increase complexity in understanding stock dynamics and optimal catch for such a stochastic and multiple-stock system. To address the issue of identifying optimal catch of stochastically growing multi stocks, we have formulated and applied a time-continuous stochastic model. The model contributes to multispecies bioeconomic management of marine ecosystems. An application of the model in a predator-prey relationship in the Barents Sea revealed that the optimal catch for stochastically growing stocks in a multispecies interaction model is different from the deterministic model.