scholarly journals Bioeconomic multistock reference points as a tool for overcoming the drawbacks of the landing obligation

2016 ◽  
Vol 74 (2) ◽  
pp. 511-524 ◽  
Author(s):  
Dorleta García ◽  
Raúl Prellezo ◽  
Paz Sampedro ◽  
José María Da-Rocha ◽  
José Castro ◽  
...  

The landing obligation policy was one of the major innovations introduced in the last Common Fisheries Policy reform in Europe. It is foreseen that the policy will affect the use of fishing opportunities and hence the economic performance of the fleets. The problem with fishing opportunities could be solved if single-stock total allowable catches (TACs) could be achieved simultaneously for all the stocks. In this study, we evaluate the economic impact of the landing obligation policy on the Spanish demersal fleet operating in the Iberian Sea region. To generate TAC advice, we used two sets of maximum sustainable yield (MSY) reference points, the single-stock MSY reference points defined by ICES and a set of multistock reference points calculated simultaneously using a bioeconomic optimization model. We found that the impact of the landing obligation is time and fleet dependent and highly influenced by assumptions about fleet dynamics. At fishery level, multistock reference points mitigate the decrease in the net present value generated by the implementation of the landing obligation. However at fleet level, the effect depends on the fleet itself and the period. To ensure the optimum use of fishing opportunities, the landing obligation should be accompanied by a management system that guarantees consistency between single-stock TACs. In this regard, multistock reference points represent an improvement over those currently in use. However, further investigation is necessary to enhance performance both at fleet level and in the long term.

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1568
Author(s):  
Federico Galli ◽  
Jun-Jie Lai ◽  
Jacopo De Tommaso ◽  
Gianluca Pauletto ◽  
Gregory S. Patience

Methane is the second highest contributor to the greenhouse effect. Its global warming potential is 37 times that of CO2. Flaring-associated natural gas from remote oil reservoirs is currently the only economical alternative. Gas-to-liquid (GtL) technologies first convert natural gas into syngas, then it into liquids such as methanol, Fischer–Tropsch fuels or dimethyl ether. However, studies on the influence of feedstock composition are sparse, which also poses technical design challenges. Here, we examine the techno-economic analysis of a micro-refinery unit (MRU) that partially oxidizes methane-rich feedstocks and polymerizes the syngas formed via Fischer–Tropsch reaction. We consider three methane-containing waste gases: natural gas, biogas, and landfill gas. The FT fuel selling price is critical for the economy of the unit. A Monte Carlo simulation assesses the influence of the composition on the final product quantity as well as on the capital and operative expenses. The Aspen Plus simulation and Python calculate the net present value and payback time of the MRU for different price scenarios. The CO2 content in biogas and landfill gas limit the CO/H2 ratio to 1.3 and 0.9, respectively, which increases the olefins content of the final product. Compressors are the main source of capital cost while the labor cost represents 20–25% of the variable cost. An analysis of the impact of the plant dimension demonstrated that the higher number represents a favorable business model for this unit. A minimal production of 7,300,000 kg y−1 is required for MRU to have a positive net present value after 10 years when natural gas is the feedstock.


2000 ◽  
Vol 30 (11) ◽  
pp. 1817-1823 ◽  
Author(s):  
Karin Öhman

Harvest activities tend often to create landscapes where the old forest is fragmented into isolated patches that provide marginal conditions for species that inhabit forest interiors. This paper presents a long-range planning model designed to maximize the net present value and to create continuous patches of old forest. In this model, the spatial structure of old forest is controlled by core area and edge habitats. Core area is defined as the area of old forest that is free of edge effects from surrounding habitats. The core area requirement is set to a fixed value for each of a number of time periods, whereas the area of edge habitats, which should be as small as possible, is weighted against the net present value. The model is applied in a case study to an actual landscape consisting of 755 stands of forest in northern Sweden and solved using simulated annealing. The results show that distinct continuous patches of old forest are created when both a core area requirement and consideration of the amount of edge habitats are included in the problem formulation. The cost of creating continuous areas of old forest was found to be significant.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ömer Esen ◽  
Gamze Yıldız Seren

PurposeThis study aims to empirically examine the impact of gender-based inequalities in both education and employment on economic performance using the dataset of Turkey for the period 1975–2018.Design/methodology/approachThis study employs Johansen cointegration tests to analyze the existence of a long-term relation among variables. Furthermore, dynamic ordinary least squares (DOLS) and fully modified ordinary least squares (FMOLS) estimation methods are performed to determine the long-run coefficients.FindingsThe findings from the Johansen cointegration analysis confirm that there is a long-term cointegration relation between variables. Moreover, DOLS and FMOLS results reveal that improvements in gender equality in both education and employment have a strong and significant impact on real gross domestic product (GDP) per capita in the long term.Originality/valueThe authors expect that this study will make remarkable contributions to the future academic studies and policy implementation, as it examines the relation among the variables by including the school life expectancy from primary to tertiary based on the gender parity index (GPI), the gross enrollment ratio from primary to tertiary based on GPI and the ratio of female to male labor force participation (FMLFP) rate.


Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 458 ◽  
Author(s):  
Agnieszka Stec ◽  
Martina Zeleňáková

Decentralized water systems are perceived as solutions that not only save water, but also as a way to partially or completely become independent from centralized suppliers. Taking this into account, an analysis of the effectiveness of rainwater harvesting systems (RWHS) for toilet flushing in existing academic facilities located in Poland and in Slovakia was carried out. The tests took into account the different volumes of storage tanks collecting rainwater. On the basis of two financial ratios, namely Net Present Value and Discounted Payback Period, the profitability of these systems was also assessed. The research was extended by the sensitivity analysis, which allowed determination of the impact of changes in individual cost components on the financial effectiveness of the investments considered. The results obtained clearly showed that the implementation of RWHS in the dormitory in Rzeszów was unprofitable for all tank capacities tested, and the payback period significantly exceeded the period of 30 years accepted for the analysis. Completely different results were obtained for RWHS in a dormitory located in the city of Košice, for which the financial ratios NPV (Net Present Value) and DPP (Discounted Payback Period) were very favorable. It was also confirmed by the results of the sensitivity analysis. The use of rainwater for toilet flushing caused that it was possible to achieve water savings of an average of 29% and 18%, respectively, for facilities located in Slovakia and Poland. The results of the research have a practical aspect and can provide an indication for potential investors and managers of academic facilities, similar to those analyzed in the article. Taking into account that in many countries water and sewage rates are significantly higher than in Poland and Slovakia, the cost-effectiveness of using the analyzed installation options in these countries could be even higher.


2011 ◽  
Vol 68 (5) ◽  
pp. 919-928 ◽  
Author(s):  
Rolf A. Groeneveld

Abstract Groeneveld, R. A. 2011. Quantifying fishers' and citizens' support for Dutch flatfish management policy. – ICES Journal of Marine Science, 68: 919–928. Fisheries policy is most effective when supported by fishers and the general public. Dutch citizens' and fishers' support for a selection of policy alternatives to enhance the sustainability of the Dutch North Sea cutter fleet is estimated, and the same groups' support for policy alternatives is expressed in monetary terms. A stated-choice survey was held among a representative sample of the Dutch population to assess their average willingness to pay for a selection of policy objectives, and among Dutch flatfish fishers to estimate their willingness to accept a selection of policy measures. The results indicate that citizens are most concerned about the impact of beam trawling on benthic megafauna, because they are on average willing to pay €21.46 per year to reduce the impact, but reducing fishing pressure in the plaice (Pleuronectes platessa) spawning period and restoring spawning-stock biomass of plaice and sole (Solea solea) to the levels of maximum sustainable yield are also supported. Fishers seem to support enhanced fines for the use of illegal fishing gear, but they are most opposed to increasing the minimum landing size of sole.


1994 ◽  
Vol 24 (9) ◽  
pp. 1758-1765 ◽  
Author(s):  
David J. Anderson ◽  
B. Bruce Bare

A deterministic dynamic programming formulation of the transition uneven-aged stand management problem is presented. Using a previously published northern hardwoods growth model, a forward recursive, discrete, two-state problem that maximizes the net present value of harvested trees at each stage is developed. State variables represent the total number of trees and the total basal area per acre. A neighborhood storage concept previously published is used to reduce the number of states considered at each stage. Two harvest allocation rules are used to assign the harvested basal area to individual diameter classes. Terminal end point conditions and stage to stage sustainability are not required. Results from four base runs of the model are presented and compared with previously published results. Each run produces significantly different optimal paths, with one showing a higher net present value than any previously published. Sensitivity runs illustrate the impact of changes in interest rates, width of neighborhood storage class, and initial conditions. Dynamic programming offers promise for analyzing uneven-aged stand management problems.


2005 ◽  
Vol 26 (3) ◽  
pp. 287-294 ◽  
Author(s):  
Katinka Weinberger

Background Evaluation of agricultural research often neglects consumption and nutrition aspects. Yet agricultural research can address micronutrient malnutrition by improving both quantity and quality of food intake. Objective To briefly review the conceptual linkages between agriculture and nutrition, to estimate the strength of the relationship between iron intake and productivity outcomes, and to estimate the nutritional benefit of improved mungbean varieties in terms of net present value. This paper presents a methodology for assessing the nutritional impact of mungbean, and summarizes current impact evidence on the path from mungbean research to consumption. Methods A consumption study was conducted among female piece-rate workers in Pakistan to analyze the impact of iron consumption on productivity, measured in wages. A two-stage least-squares analysis was used to estimate the elasticity of iron intake on wages. The results derived from this study were extrapolated to country level using secondary data sources. Results We found that anemia among women was widespread. Approximately two-thirds of women suffered from mild or severe anemia (Hb < 12 g/dL). We found the elasticity of bioavailable iron on productivity measured in wages was 0.056, and the marginal effect was 9.17 Pakistani rupees per additional mg of bioavailable iron consumed. Using the model results we estimated the impact of mungbean research on nutrition, in terms of productivity effects, and found it was substantial, ranging from US$7.6 to 10.1 million cumulative present value (in 1995 US$ at 5% discount rate). Conclusions Agriculture certainly plays an important role in the reduction of malnutrition. Agricultural research has greatly contributed to the reduction of hunger and starvation by providing millions of hungry people with access to low-cost staple foods. Now, as the challenge shifts to the reduction of micronutrient deficiencies, more efforts must be directed toward crops high in micronutrients, such as pulses and vegetables.


1988 ◽  
Vol 64 (2) ◽  
pp. 127-131 ◽  
Author(s):  
Kenneth J. Mitchell

Intensive forest management requires an understanding of the effect that silvicultural treatments have on wood properties, standing yield, log quality, product value, and net present value. These needs are addressed by a system of models (SYLVER) which includes the Tree and Stand Simulator (TASS), Root Rot Simulator (ROTSIM), Sawmill Simulator (SAWSIM), and the new Financial Analysis System (FAN$Y). The latter will be used by field foresters to compare the merits of candidate treatments for specific stands. Key words: Silviculture, growth and yield, juvenile wood, log quality, end-product value, net present value, Pseudotsuga menziesii, Phellinus weirii, modelling, TASS, ROTSIM, SAWSIM, FAN$Y, SYLVER.


Sign in / Sign up

Export Citation Format

Share Document