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| Kristofersson, Dadi; Rickertsen, Kyrre. |
| Fishers in quota-regulated fisheries find it to their advantage to discard less valuable fish at sea to increase the value of their catch. A theoretical model describing the high-grading behavior of fishers is presented, and an empirical model is derived as well as a testing strategy to test for high-grading and to estimate the discarded amount of each grade. The model is applied to data for the Icelandic quota regulated cod fishery during the period September 1998 to June 2001. The results indicate that highgrading occurs in the Icelandic cod fishery for both long-line and net vessels. However, the discard rates are small, and the results clearly suggest that the ban on discards in Iceland has effectively dealt with high-grading. The estimated discard... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: ITQ's; Highgrading; Empirical estimation; Resource /Energy Economics and Policy; Q21; Q22; C12. |
| Ano: 2005 |
URL: http://purl.umn.edu/24722 |
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| Guttormsen, Atle G.; Kristofersson, Dadi; Navdal, Eric. |
| It has become clear that exploitation of natural resources may result in evolutionary selection pressure resulting in morphological changes of a species over time. This potentially adverse effect should be taken into account when regulating the use of such resources. In this paper we present a bioeconomic model where we analyse the effect of selective harvesting on genetic frequency for one specific gene in terms of the socially optimal long-term management of the resource. It is assumed that the individuals carrying the gene have a lower natural mortality rate but are also more valuable to catch. Results indicate that the relationship between the natural rate of selection against less valuable individuals and the interest rate is crucial in determining... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Research and Development/Tech Change/Emerging Technologies. |
| Ano: 2005 |
URL: http://purl.umn.edu/19354 |
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| Kristofersson, Dadi; Rickertsen, Kyrre. |
| A theoretical model with nonlinear discarding costs is constructed to describe highgrading in a fishery with an Individual Transferable Quota (ITQ) program. The model shows that ITQs provide incentives to discard fish when the hold capacity of the vessel is nonbinding. An empirical model is developed to test for highgrading and to predict the discarded quantities of different grades of fish. This model is applied to the Icelandic ITQ-regulated cod fishery. Net and long-line vessels are involved in highgrading and the quota price induces highgrading for net vessels. The predicted total discarded quantities are 4.7% and 2.7% of total landings for net and long-line vessels, respectively. Long-line and net vessels are predicted to discard 18% and 76% of... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Resource /Energy Economics and Policy. |
| Ano: 2005 |
URL: http://purl.umn.edu/19330 |
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| Kristofersson, Dadi; Rickertsen, Kyrre. |
| The paper is concerned with efficient estimation of characteristics demand. We derive and estimate an inverse input demand system for quality characteristics by using 172,946 observations over 881 trading days in the Icelandic fish auctions. An improved estimation method based on an expanded random coefficient model is suggested as an alternative to the currently used two-stage method of Brown and Rosen (1982). The estimates demonstrate the improved efficiency of the suggested method. A number of empirical results emerge, including a general increase in the demand for quality. |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Demand and Price Analysis; C51; Q22.. |
| Ano: 2003 |
URL: http://purl.umn.edu/21926 |
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| Asche, Frank; Guttormsen, Atle G.; Kristofersson, Dadi; Roheim, Cathy A.. |
| A frequently encountered problem in import demand estimation is how to account for competition between imports and domestic production. Traditionally, use of the Armington model has been a way to handle this problem. This is a disaggregate model which distinguishes commodities by country of origin with import demand determined in a separable two-step procedure. The model appears frequently in analysis of international agricultural markets. However, the Armington model relies on a set of weak separability assumptions, which several authors have shown to be highly questionable. In this paper, a new aggregation theorem, the Generalized Composite Commodity Theorem (GCCT), is applied to test whether imports can be treated as a separate group. An advantage with... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Armington; Separability; GCCT; Demand system; Sword fish; International Relations/Trade; F18; Q11; Q22. |
| Ano: 2005 |
URL: http://purl.umn.edu/19432 |
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