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• 1. [Article] Discontinuous Sustainable Yield: The Exception or the Rule?

  The sustainable yield function is a favoured tool in fisheries policy making. Normally, this function is drawn as a continuous curve in effort-yield space. This means that sustainable yield (harvest) is ...

  Citation × Citation Citation Abstract Copy Title: Discontinuous Sustainable Yield: The Exception or the Rule? Author: Arnason, Ragnar The sustainable yield function is a favoured tool in fisheries policy making. Normally, this function is drawn as a continuous curve in effort-yield space. This means that sustainable yield (harvest) is gradually reduced to zero as fishing effort increases. This, however, does not have to be the case. The sustainable yield function may easily be discontinuous in the sense that sustained fishing effort beyond a certain critical level will lead to a discrete fall in yield to zero, i.e., a collapse of the fishery. The corresponding sustainable yield curve then has a gap at the critical fishing effort level. Clearly, the existence of such a gap has major implications for fisheries policy. It has long been recognized that depensatory biomass growth generally leads to discontinuous sustainable yield curves. What appears to be less well understood is that with fully compensatory biomass growth, fish schooling (patchy distribution of fish over the fishing grounds) generally leads to the same result. Since schooling behaviour is typical of most species of fish ― only the degree of schooling varies ― discontinuous sustainable yield functions tend to be the rule rather than the exception. This paper considers with these issues. It shows how schooling behaviour leads to discontinuities in the sustainable yield function. It explores the corresponding dynamics of the fish stock and the implications for the risk of stock collapses and fisheries policies designed to avoid them. The paper finally speculates about the impacts of profit maximizing investments by fishing firms on the existence and location of gaps in sustainable yield curves. Title: Discontinuous Sustainable Yield: The Exception or the Rule? Author: Arnason, Ragnar The sustainable yield function is a favoured tool in fisheries policy making. Normally, this function is drawn as a continuous curve in effort-yield space. This means that sustainable yield (harvest) is gradually reduced to zero as fishing effort increases. This, however, does not have to be the case. The sustainable yield function may easily be discontinuous in the sense that sustained fishing effort beyond a certain critical level will lead to a discrete fall in yield to zero, i.e., a collapse of the fishery. The corresponding sustainable yield curve then has a gap at the critical fishing effort level. Clearly, the existence of such a gap has major implications for fisheries policy. It has long been recognized that depensatory biomass growth generally leads to discontinuous sustainable yield curves. What appears to be less well understood is that with fully compensatory biomass growth, fish schooling (patchy distribution of fish over the fishing grounds) generally leads to the same result. Since schooling behaviour is typical of most species of fish ― only the degree of schooling varies ― discontinuous sustainable yield functions tend to be the rule rather than the exception. This paper considers with these issues. It shows how schooling behaviour leads to discontinuities in the sustainable yield function. It explores the corresponding dynamics of the fish stock and the implications for the risk of stock collapses and fisheries policies designed to avoid them. The paper finally speculates about the impacts of profit maximizing investments by fishing firms on the existence and location of gaps in sustainable yield curves. Close

• 2. [Article] The Artisanal Hilsa Fishery: economically Efficient Fisheries Policy

  The hilsa shad (Tenualosa ilisha) fishery is by far the largest single species fishery in Bangladesh. In this paper, a simple bio-economic year-class based model is developed to describe the fishery and ...

  Citation × Citation Citation Abstract Copy Title: The Artisanal Hilsa Fishery: economically Efficient Fisheries Policy Author: Arnason, Ragnar, Mome, Masud Ara The hilsa shad (Tenualosa ilisha) fishery is by far the largest single species fishery in Bangladesh. In this paper, a simple bio-economic year-class based model is developed to describe the fishery and examine its properties. With the help of this model, the optimum sustainable yield of the fishery is calculated and compared to the existing situation. The model is further used to locate socially and economically reasonably dynamic paths from the current situation to the optimal one. The results indicate that the fishing effort (measured in standardized boat units) required maintaining maximum sustainable economic benefits are about one-third of the current fishing effort. At this sustainable fishing effort level, annual net economic benefits from the fishery amount to about US$ 260 million according to my calculations compared to virtually nothing today. The present value of the fishery along a moderate effort adjustment path to this long term equilibrium position is US$ 3,650 million at 6% rate of discount. The dynamic path that maximizes the present value of the fishery involves quite dramatic effort reductions for the first two years. Such a path would increase the present value of the fishery by perhaps 8-10%. Title: The Artisanal Hilsa Fishery: economically Efficient Fisheries Policy Author: Arnason, Ragnar, Mome, Masud Ara The hilsa shad (Tenualosa ilisha) fishery is by far the largest single species fishery in Bangladesh. In this paper, a simple bio-economic year-class based model is developed to describe the fishery and examine its properties. With the help of this model, the optimum sustainable yield of the fishery is calculated and compared to the existing situation. The model is further used to locate socially and economically reasonably dynamic paths from the current situation to the optimal one. The results indicate that the fishing effort (measured in standardized boat units) required maintaining maximum sustainable economic benefits are about one-third of the current fishing effort. At this sustainable fishing effort level, annual net economic benefits from the fishery amount to about US$ 260 million according to my calculations compared to virtually nothing today. The present value of the fishery along a moderate effort adjustment path to this long term equilibrium position is US$ 3,650 million at 6% rate of discount. The dynamic path that maximizes the present value of the fishery involves quite dramatic effort reductions for the first two years. Such a path would increase the present value of the fishery by perhaps 8-10%. Close

• 3. [Article] Fisheries Management Services in Iceland: Costs and Arrangements

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  Citation × Citation Citation Abstract Copy Title: Fisheries Management Services in Iceland: Costs and Arrangements Author: Arnason, Ragnar presentation Title: Fisheries Management Services in Iceland: Costs and Arrangements Author: Arnason, Ragnar presentation Close

• 4. [Article] Stock and (possibly) path dependent technologies

  According to conventional economic wisdom the economically more efficient technology will always outcompete the less efficient. This hypothesis has usually been taken to hold for the exploitation of common ...

  Citation × Citation Citation Abstract Copy Title: Stock and (possibly) path dependent technologies Author: Arnason, Ragnar, Willmann, Rolf According to conventional economic wisdom the economically more efficient technology will always outcompete the less efficient. This hypothesis has usually been taken to hold for the exploitation of common pool renewable natural resources such as fish stocks. This paper claims that, while this is not necessarily false, it may be too optimistic. The paper shows that what constitutes the most efficient technology may switch depending on biomass size. It also shows that once effective fisheries management is introduced and biomass recovers, a return to the initially most efficient technology may not be possible because of its embeddedness in traditional knowledge and institutions which might have become forgotten or lost. Thus, there may be a degree of technological irreversibilty in fisheries and other natural reource utilization. The paper’s findings seem relevant to many situations in developing countries fisheries where labour- intensive technologies are displaced by more capital-intensive technologies, often introduced with government subsidies. The uncontrolled expansion of the latter then creates the condition, i.e. reduced stock sizes, especially in inshore areas, that disadvantages the intially more efficient labour-intensive technologies. Title: Stock and (possibly) path dependent technologies Author: Arnason, Ragnar, Willmann, Rolf According to conventional economic wisdom the economically more efficient technology will always outcompete the less efficient. This hypothesis has usually been taken to hold for the exploitation of common pool renewable natural resources such as fish stocks. This paper claims that, while this is not necessarily false, it may be too optimistic. The paper shows that what constitutes the most efficient technology may switch depending on biomass size. It also shows that once effective fisheries management is introduced and biomass recovers, a return to the initially most efficient technology may not be possible because of its embeddedness in traditional knowledge and institutions which might have become forgotten or lost. Thus, there may be a degree of technological irreversibilty in fisheries and other natural reource utilization. The paper’s findings seem relevant to many situations in developing countries fisheries where labour- intensive technologies are displaced by more capital-intensive technologies, often introduced with government subsidies. The uncontrolled expansion of the latter then creates the condition, i.e. reduced stock sizes, especially in inshore areas, that disadvantages the intially more efficient labour-intensive technologies. Close

• 5. [Article] Optimal Dynamic Enforcement of A Fishery

  It has been established that the path of a fishery over time, i.e. stocks, fleets, effort and profits, depends inter alia on the enforcement of the fisheries management rules in place. It has further been ...

  Citation × Citation Citation Abstract Copy Title: Optimal Dynamic Enforcement of A Fishery Author: Arnason, Ragnar It has been established that the path of a fishery over time, i.e. stocks, fleets, effort and profits, depends inter alia on the enforcement of the fisheries management rules in place. It has further been established that optimal enforcement of fisheries management rules depends inter alia on the shadow value of biomass at each point of time. This raises the question of the optimal path of fisheries enforcement over time. Given a certain state of the fishery, a fisheries management system, enforcement tools and a penalty structure, what would be the optimal enforcement effort over time? This paper deals with this issue. Given the above constraints, it attempts to solve the dynamic problem of optimal enforcement of the fisheries rules over time. Not surprisingly, it turns out that the optimal enforcement effort should definitely not be constant. On the contrary, given the other parameters of the problem, optimal enforcement is generally a function of the state of the fish stocks at each point of time. In fact, it appears that the optimal enforcement effort should be a monotonically declining function of the fish stocks (provided a sustainable fishery is optimal). A related issue is the target harvest that may be set under the fisheries management system. The optimal path of this over time and its interaction with optimal enforcement is also explored. Title: Optimal Dynamic Enforcement of A Fishery Author: Arnason, Ragnar It has been established that the path of a fishery over time, i.e. stocks, fleets, effort and profits, depends inter alia on the enforcement of the fisheries management rules in place. It has further been established that optimal enforcement of fisheries management rules depends inter alia on the shadow value of biomass at each point of time. This raises the question of the optimal path of fisheries enforcement over time. Given a certain state of the fishery, a fisheries management system, enforcement tools and a penalty structure, what would be the optimal enforcement effort over time? This paper deals with this issue. Given the above constraints, it attempts to solve the dynamic problem of optimal enforcement of the fisheries rules over time. Not surprisingly, it turns out that the optimal enforcement effort should definitely not be constant. On the contrary, given the other parameters of the problem, optimal enforcement is generally a function of the state of the fish stocks at each point of time. In fact, it appears that the optimal enforcement effort should be a monotonically declining function of the fish stocks (provided a sustainable fishery is optimal). A related issue is the target harvest that may be set under the fisheries management system. The optimal path of this over time and its interaction with optimal enforcement is also explored. Close

• 6. [Article] Rents and Rents Drain in the Icelandic Cod Fishery

  This paper estimates current resource rents being generated in the Icelandic cod fishery and compares them to the maximum sustainable attainable ones. For this purpose a simple aggregative model of the ...

  Citation × Citation Citation Abstract Copy Title: Rents and Rents Drain in the Icelandic Cod Fishery Author: Arnason, Ragnar This paper estimates current resource rents being generated in the Icelandic cod fishery and compares them to the maximum sustainable attainable ones. For this purpose a simple aggregative model of the cod fishery is specified and empirically estimated. It is found that in spite of the cod stock being in a fairly depressed state, substantial economic rents are currently being generated in this fishery. No doubt this is primarily due to the effects of the ITQ system in this fishery. Current rents, however, are only about a third of the rents that would pertain in a profit maximizing sustainable position of this fishery. Thus, compared to the maximum, the Icelandic cod fishery appears to be subject to significant rents loss. Most of the rents gain from the current position of the fishery to the profit maximizing sustainable position is due to an increased cod stock. A much smaller part is due to reduced fishing effort. Title: Rents and Rents Drain in the Icelandic Cod Fishery Author: Arnason, Ragnar This paper estimates current resource rents being generated in the Icelandic cod fishery and compares them to the maximum sustainable attainable ones. For this purpose a simple aggregative model of the cod fishery is specified and empirically estimated. It is found that in spite of the cod stock being in a fairly depressed state, substantial economic rents are currently being generated in this fishery. No doubt this is primarily due to the effects of the ITQ system in this fishery. Current rents, however, are only about a third of the rents that would pertain in a profit maximizing sustainable position of this fishery. Thus, compared to the maximum, the Icelandic cod fishery appears to be subject to significant rents loss. Most of the rents gain from the current position of the fishery to the profit maximizing sustainable position is due to an increased cod stock. A much smaller part is due to reduced fishing effort. Close

• 7. [Article] ITQ Prices: What do they Reveal?

  Presentation

  Citation × Citation Citation Abstract Copy Title: ITQ Prices: What do they Reveal? Author: Arnason, Ragnar Presentation Title: ITQ Prices: What do they Reveal? Author: Arnason, Ragnar Presentation Close

• 8. [Article] Economically Sensible Caps on ITQ-Holdings

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  Citation × Citation Citation Abstract Copy Title: Economically Sensible Caps on ITQ-Holdings Author: Arnason, Ragnar presentation Title: Economically Sensible Caps on ITQ-Holdings Author: Arnason, Ragnar presentation Close

• 9. [Article] On the Economic Distortion of Pure Resource Rent Taxation

  It is often taken for granted that taxation of rents is economically nondistortive. In certain areas of natural resource use, e.g. oil extraction and fisheries, this nondistortion principle has been used ...

  Citation × Citation Citation Abstract Copy Title: On the Economic Distortion of Pure Resource Rent Taxation Author: Arnason, Ragnar It is often taken for granted that taxation of rents is economically nondistortive. In certain areas of natural resource use, e.g. oil extraction and fisheries, this nondistortion principle has been used to justify taxation of what is regarded as resource rents. This paper challenges the view that such taxation is generally nondistortive. Within the framwork of a general model of natural resource extraction, the paper argues that taxation of resource rents will in general affect the time profile of natural resource extraction. The paper, moreover, argues that through its impact on exit and entry, resource rent taxation will generally affect the number and composition of firms in the industry and may in this way have a secondary efficiency impact. Title: On the Economic Distortion of Pure Resource Rent Taxation Author: Arnason, Ragnar It is often taken for granted that taxation of rents is economically nondistortive. In certain areas of natural resource use, e.g. oil extraction and fisheries, this nondistortion principle has been used to justify taxation of what is regarded as resource rents. This paper challenges the view that such taxation is generally nondistortive. Within the framwork of a general model of natural resource extraction, the paper argues that taxation of resource rents will in general affect the time profile of natural resource extraction. The paper, moreover, argues that through its impact on exit and entry, resource rent taxation will generally affect the number and composition of firms in the industry and may in this way have a secondary efficiency impact. Close

• 10. [Article] Global Trends in Capture Fisheries, With an Estimate of Global Losses in Marine Fisheries Resource Rents

  Abstract only.

  Citation × Citation Citation Abstract Copy Title: Global Trends in Capture Fisheries, With an Estimate of Global Losses in Marine Fisheries Resource Rents Author: Franz, Nicole, Arnason, Ragnar, Willmann, Rolf, Kelleher, Kieran Abstract only. Title: Global Trends in Capture Fisheries, With an Estimate of Global Losses in Marine Fisheries Resource Rents Author: Franz, Nicole, Arnason, Ragnar, Willmann, Rolf, Kelleher, Kieran Abstract only. Close