Blar i Working papers (SNF) på forfatter "Steinshamn, Stein Ivar"
-
A bioeconomic analysis of an age-structured fish stock continuous in time and age
Steinshamn, Stein Ivar; Golubtsov, Peter (Working paper;2014:15, Working paper, 2015-03)An age-structured bioeconomic model, that is completely continuous in state and time, is developed. To make the model more realistic, a nonlinear recruitment function is introduced and steady state solutions are studied ... -
Assimilation of time series data into a dynamic bioeconomic fisheries model : an application to the North East Arctic cod stock
Ussif, Al-Amin M.; Sandal, Leif Kristoffer; Steinshamn, Stein Ivar (Working Paper, Working paper; Working paper, 2003-01)This paper combines the elegant technique of Data Assimilation and a Monte Carlo procedure to analyze time series data for the North East Arctic Cod stock (NEACs). A simple nonlinear dynamic resource model is calibrated ... -
Benefits of stock enhancement: The case of the Iranian kutum fishery
Steinshamn, Stein Ivar; Borujeni, Pezhman Alaei (Working paper;14/14, Working paper, 2014-12)Harvesting of the fish resources as an economic activity, which is strictly tied to biological matters, needs to be modeled proficiently through bioeconomic analysis. In this study, a bioeconomic age-structured model is ... -
Climate change, poverty and food security : the role of the small-scale fisheries sector
Singh, Balbir; Steinshamn, Stein Ivar (Working Paper, Working paper, 2005-12)Coastal small scale fisheries and communities in the developing countries are vulnerable to global climate change. The consequences occur directly due to the impact of rising temperatures on movement of fish resources and ... -
Continuous harvesting costs in sole-owner fisheries with increasing marginal returns
Sandal, Leif Kristoffer; Steinshamn, Stein Ivar; Maroto, Jose M.; Moran, Manuel (Working paper, Working paper, 2009-06)We develop a bioeconomic model to analyze a sole-owner fishery with fixed costs as well as a continuous cost function for the generalized Cobb-Douglas production function with increasing marginal returns to effort level. ... -
Dynamic cournot-competitive harvesting of a common pool resource
Sandal, Leif Kristoffer; Steinshamn, Stein Ivar (Working Paper, Working paper; Working paper, 2003-01)A variant of the classical harvesting game, where a number of competing agents simultaneously harvest a common-pool natural resource, is analysed. The harvesting at each time is a Cournot competition. The critical assumption ... -
Economic evaluation of the fisheries policies in Denmark, Iceland and Norway : some performance indicators
Arnason, Ragnar; Sandal, Leif Kristoffer; Steinshamn, Stein Ivar; Vestergaard, Niels (Working Paper, Working paper; Working paper, 2002-08)The economic efficiency of the Danish, Icelandic and Norwegian cod fisheries is examined. For this purpose nonlinear aggregate models of these three fisheries are constructed. A particular mathematical approach to calculate ... -
Estimation of biological and economic parameters of a bioeconomic fisheries model using dynamical data assimilation
Ussif, Al-Amin M.; Sandal, Leif Kristoffer; Steinshamn, Stein Ivar (Working Paper, Working paper; Working paper, 2002-03)A new approach of model parameter estimation is used with simulated measurements to recover both biological and economic input parameters of a natural resource model. The data assimilation technique is the variational ... -
Fish wars on the high seas : a straddling stock competition model
McKelvey, Robert W.; Sandal, Leif Kristoffer; Steinshamn, Stein Ivar (Working Paper, Working paper; Working paper, 2001-04)The post World War II era saw the development of powerful self-contained fishing fleets, so-called distant-water fleets (DWFs), which roamed the world’s oceans, seeking out rich harvesting targets wherever they might be ... -
Fish wars on the high seas : erecting economic barriers to entry
McKelvey, Robert W.; Sandal, Leif Kristoffer; Steinshamn, Stein Ivar (Working paper, Working paper; Working paper, 2000-10)The 1993 U.N. Straddling Stock Agreement prescribes a multi-national organizational structure for management of an exploited marine fish stock, one whose range straddles both “Extended Economic Zones” (EEZs) and high seas ... -
Generalization of age-structured bioeconomic models in theory and practice
Steinshamn, Stein Ivar (Working paper, Working paper, 2010-08)The harvesting functions and the stock dynamics in age-structured bioeconomic models are generalized in order to incorporate density dependence. Using this generalization anything from completely uniformly distributed fish ... -
Implications of a nested stochastic/deterministic bio-economic model for a pelagic fishery
McDonald, A. David; Sandal, Leif Kristoffer; Steinshamn, Stein Ivar (Working Paper, Working paper; Working paper, 2001-05)Use is made of an economically optimal feedback rule to determine optimal levels of exploitation of a pelagic fish species. Data from the southern bluefin tuna fishery for the years 1960 - 1996 are utilised to apply this ... -
Klimaendringer og havbruk
Steinshamn, Stein Ivar (Arbeidsnotat, Working paper, 2009-09)Vi ser på noen mulige konsekvenser av klimaendringer, og spesielt temperaturøkning som følge av global oppvarming, på havbrukssektoren. Dette blir gjort ved at en først går gjennom litteraturen på området og oppsummerer ... -
Long-term sustainable and optimal management of multispecies stochastic fisheries
Poudel, Diwakar; Sandal, Leif Kristoffer; Steinshamn, Stein Ivar; Kvamsdal, Sturla Furunes (Working papers;01/14, Working paper, 2014-02)Multispecies fisheries management is the first step towards ecosystem-based fisheries management. Multispecies management accounts for a number of species and their physical, biological, and economic interactions. These ... -
Market-based fisheries management : a selected overview
Steinshamn, Stein Ivar (Working Paper, Working paper, 2005-12)The aim of this review article is to give an overview over some of the literature on so-called market based management in fisheries. Market-based management is, however, a term that has been used with different meanings ... -
On the dynamics of commercial fishing and parameter identification
Ussif, Al-Amin M.; Sandal, Leif Kristoffer; Steinshamn, Stein Ivar (Working Paper, Working paper; Working paper, 2002-03)This paper has two main objectives. The first is to develop a dynamic model of commercial fisheries different from most existing models that assume optimizing behavior. The industry is assumed to have a well-defined index ... -
Optimal age-structured harvest in a dynamic model with heterogenous capital
Sandal, Leif Kristoffer; Steinshamn, Stein Ivar (Working Paper, Working paper, 2003-08)A dynamic optimization model with four state variables and two control variables is developed in order to analyze a fishery where on fleet-segment is targeting young fish and another fleet-segment is targeting older fish ... -
Optimal feedback controls : comparative evaluation of the cod fisheries in Denmark, Iceland and Norway
Arnason, Ragnar; Sandal, Leif Kristoffer; Steinshamn, Stein Ivar; Vestergaard, Niels (Working paper, Working paper; Working paper, 2000-01)The purpose of this paper is to compare the relative efficiency of the fish harvesting policies of Iceland, Norway and Denmark. We have chosen to concentrate on the cod fishery as this is the single most important fishery ... -
Optimal population and capital dynamics in fisheries with irreversible investments
Sandal, Leif Kristoffer; Steinshamn, Stein Ivar; Hoff, Ayoe (Working paper, Working paper, 2007-06)A multi-dimensional, non-linear dynamic model in continuous time is presented for the purpose of finding the optimal combination of exploitation and capital investment in optimal renewable resource management. Non-malleability ... -
Optimization in the ‘Pelagic complex’ : a multi-species competition model of North East Atlantic fisheries
Ekerhovd, Nils-Arne; Steinshamn, Stein Ivar (Working paper;2014:12, Working paper, 2015-03)Optimal management of herring, mackerel and blue whiting in the North East Atlantic is analyzed. The main motivation is to quantify the potential gain from implementing multi-species management compared to traditional ...