Surplus Production Research Articles

European anchovy's abundance, more affected by climatic conditions than fishing activities in the northwest African waters.

The marine waters off the coast of northwest Africa are known for being highly productive upwelling regions in the Eastern Atlantic Ocean. The present study evaluated the combined effects of climate change and sustainable fishing levels on the long-term sustainability of European anchovy (Engraulis encrasicolus), a target pelagic species found along the West African coastal waters. The present study used survey biomass time series from survey vessels and species catch time series from commercial fisheries operating in the region. Hence, we investigated the relationship between fishing dynamics and environmental factors. The status of anchovy stock was determined by analyzing changes in different initial depletion rates using a state-space Bayesian surplus production model. We used Principal component analysis to identify the essential environmental data set, while Generalized Additive Models (GAM) were employed to determine the influence of the environment on fisheries. The stock assessment model revealed that fishing intensity did not affect the abundance of anchovy in the region even when tested under different biomass depletion scenarios. However, by employing GAMs, the research assessed the impact of environmental variables on fish biomass, indicating that sea surface temperature (SST) significantly influences anchovy abundance in the region. The latitudinal gradient also had a significant influence on this species' abundance. These findings underscore the vulnerability of the small-scale fisheries sector in the tropical upwelling zone to climate change. The study concludes that even in the face of potential negative impacts from environmental factors, optimizing fishing methods can contribute to the preservation of pelagic resources in the region. It emphasizes the importance of managing fishery resources in a sustainable, economically viable, and socially acceptable way.

Acceptorless Dehydrogenation of Glycerol Catalysed by Ir(III) Complexes with Carbohydrate‐Functionalised Ligands: A Sweet Pathway to Produce Hydrogen and Lactic Acid

AbstractGlycerol, a by‐product of biodiesel production, has gained prominence as a precious platform chemical. To enhance the economic viability of the biodiesel production process and address the surplus of glycerol production, it is essential to transform it into value‐added products. In this context, homogeneous catalysis offers a promising avenue for glycerol valorisation. In this study, we introduce a family of iridium complexes bearing picolineamidate ligands with glucose‐functionalised substituents as novel homogeneous catalysts for glycerol to hydrogen and lactic acid conversion. These complexes exhibit high activity (conversion up to 53.3 %) and 99 % selectivity after 24 hours of reaction (TOFMAX=159 h−1, TON24h=2498). Notably, the reaction occurs under ambient air and at milder temperature conditions (120 °C) compared to other catalysts. These efforts in glycerol valorisation contribute to reducing biodiesel production costs, increasing the competitiveness of biofuels against petroleum‐based liquid fuels, giving rise to H2, through a global process with negative carbon dioxide emission, and lactic acid utilizable, among other, as a monomer for the synthesis of biodegradable plastics.

What do urban consumers want? Findings from a discrete choice experiment on the preference for locally produced staple food in Central Africa: Evidence from the Democratic Republic of Congo (DRC)

ABSTRACT A discrete choice experiment in Kinshasa (DRC) investigated urban consumers' preferences between imports and local options for five staple foods – cassava, rice, maize, sugar and cooking oil – under a random utility model. We also examined how distance, packaging and price influenced consumer choice. To assess whether preferences could be manipulated, we introduced two treatment groups – local, import – and a control group. We did not find support for a preference for imports. Instead, there is a statistically significant preference for local products, with the exception of sugar. Respondents are willing to pay 28% more for local food, a premium quantified at 1540 CF (.93 USD) per kg for maize and 1091CF (.66 USD) per litre for oil. Packaging is an attribute of influence as the willingness to pay (WTP) in full remains positive when products interact with packaging and with price. There is demand for local products for which consumers are willing to pay a premium. Yet, DRC imports 1.5 billion dollars of food yearly with only 10% of its arable land exploited. The increased urban consumption of imports does not signify a bias against local products, but rather points to structural issues undermining local supply. DRC needs to develop local value chains linking rural farmers to urban markets through the transformation of local foods to meet urban needs and to convert the WTP into a producer surplus benefiting rural livelihoods.

Balancing the tradeoff between regulation and innovation for artificial intelligence: An analysis of top-down command and control and bottom-up self-regulatory approaches

In response to the rapid development of AI, several governments have established a variety of regulatory interventions for this technology. While some countries prioritize consumer protection through stringent regulation, others promote innovation by adopting a more hands-off approach. However, this tradeoff has not been analyzed systematically. We developed an economic theory on how the welfare-maximizing level of regulatory stringency for AI depends on various institutional parameters. Our game-theoretic model is motivated and built upon the comparison of regulatory documents for AI from the EU, the UK, the US, Russia, and China. The results show that if a government strives to find the right balance between innovation and consumer protection to maximize actual consumer welfare, stringent regulation is optimal when foreign competition is either high or low, whereas light-touch regulation is optimal when foreign competition is intermediate. Meanwhile, minimal regulation is rationalizable only if a government prioritizes other objectives in its agenda, such as maximizing innovation, domestic producer surplus, or perceived consumer welfare.

Circular vs One-Way Production Processes: Two Different Views on Production and Income Distribution

ABSTRACT This paper examines two distinct representations of production processes: circular production, where commodities function as both inputs and outputs, and one-way production, which starts with factors of production and ends with finished goods. These frameworks offer different views on profits. In circular systems, profits arise from surplus production, while in one-way systems, they appear to emerge from price differences between final goods and inputs. Using Sraffa’s price equations, we analyse the properties of both systems. We demonstrate that while one-way systems seem to allow for profit increases by raising prices, this is an illusion as it ultimately reduces real wages, the true source of profits. Additionally, we show that one-way systems become circular when real wages are fixed. Finally, the paper discusses how this distinction is important in understanding the shift from Walras’ general equilibrium theory to neo-Walrasian formulations. This study highlights the importance of circularity in the functioning of capitalist economies and its implications for the theory of distribution.

Towards strategic interventions for global food security in 2050

This study aims to explore global food security, focusing on major cereal crops across different Agroecological Zones (AEZs). By projecting cereal production under different Shared Socioeconomic Pathways, insights into the challenges for achieving global food security by 2050 are drawn. The study identifies ‘critical’ risks in countries like Chad, Sudan, Algeria, Somalia, and Namibia in Africa, parts of Central Asia and the Middle East (Saudi Arabia), western USA, and Australia, due to high water stress combined with severe production deficits. However, implementing strategic interventions, like increasing harvested area, can significantly reduce these risks, potentially leading to surplus production in some regions. The regions still under cereal production deficit with such mitigation strategies are categorized in terms of risk to food security, considering water stress and import dependency. Iran, Venezuela, Sub-Saharan Africa, Saudi Arabia, parts of Southeastern Asia are projected to face persistent cereal production deficits and high import dependency by the mid-20th century. The study underlines the necessity for water-saving technologies and effective governance to balance crop production and water use, particularly in regions experiencing water scarcity.

Understanding Stakeholder Perspectives: Towards the Design of a Serious Game for Positive Energy Districts

Positive Energy Districts (PEDs) are highly energy-efficient urban areas that manage a surplus production of renewable energy. Recognising the key role they can play in the transition to a less carbon-dependent society, the European Commission launched its PED Programme in 2018, to implement and support the development of PEDs. However, as PEDs are still a relatively new concept, their implementation can be challenging, and local administrators often lack clear guidance and reference points for their design, implementation and evaluation. To address this issue, the Positive RObust PEd Localities (PROPEL) project has among its main objectives the design of a serious game to provide practical insights and user-friendly tools for local administrators interested in implementing and developing PEDs. Indeed, by drawing on the power of digital games to set goals and allow the player to autonomously define a strategy to achieve them within a set of constraints, serious games can be a very powerful tool to support local administrators in their decision-making process, enabling them to explore multiple scenarios and to evaluate the results of their choices. This paper outlines the design principles and the main features of a serious game aimed at supporting local administrators in the implementation of PEDs. These design principles and features are derived from a research process comprising several steps. Firstly, the drivers and barriers to the adoption of a serious game among local administrators were identified. This was done through in-depth interviews with local administrators and PEDs experts from the different countries involved in the PROPEL project, namely Italy, Sweden, and Turkey. Secondly, a comparative analysis of serious games developed for related research purposes was carried out. This provided further suggestions for the features of the serious game. The findings underscore the significance of incorporating real data, adopting a modular structure to emulate the systemic complexity of PEDs, and ensuring accessibility across multiple devices as paramount features that the serious game should have.

IDENTIFIKASI KELEMBAGAAN PERTANIAN DAN PERANANNYA PADA SUBSISTEM PRODUKSI TANAMAN PADI SAWAH DI DESA BUKIT PARIAMAN KECAMATAN TENGGARONG SEBERANG

Agricultural Institutions are a driving factor in achieving agricultural resource management that encourages the achievement of farmer welfare. The existence of important physical and management aspects is studied, especially in rice producing centers, in relation to their contribution to the food supply. The objective of this research to identify existing agricultural institutions in Bukit Pariaman Village, to identify the role of farming institutions in the rice farming production subsystem, and analyze farmers' access to existing agricultural institutions in Bukit Pariaman Village. The research was conducted in Bukit Pariaman Village, Tenggarong Seberang District, Kutai Kartanegara Regency in May-July 2024. The sampling method was purposive sampling. Data analysis used descriptive analysis and perception analysis of access to agricultural institutions. The research results showed that agricultural institutions in Bukit Pariaman Village are adequate and well accessible. The role in the production subsystem was demonstrated by the achievement of an annual rice production surplus of 88.81%.

Making of the marginal: gender in a new education city

ABSTRACT Global urban studies are undergoing a paradigm shift recognizing the link between urban and rural studies. In this sense, ‘agrarian urbanism’ has become the research focus, especially in the Global South. This paper analyses the changing social relations in Sonipat (Haryana, India) after it was developed as an ‘Education city’. The focus is gender relations with analysis under two categories: ‘locals’ and ‘outsiders’. While urbanization was thought of as a linear process where surplus production in the rural areas would naturally lead to cities, in the global south capitalist real estate-led development has meant that urbanization is often superimposed on existing rural societies, pushing them towards marginalization in favor of gated enclaved urban infrastructure. Employing qualitative interviews, I hypothesize that the private capital-driven urbanization in Sonipat not only geographically marginalizes the existing villages but also engenders dissonant experiences of local and outsider women. The fault lines between the two mean that interaction between them is defined by exploitation and mutual suspicion. Further, I argue that within this dichotomy, women bear the brunt of social control, restricted movement and potential violence.

Animal and Plant Wealth and its Impact on the Economy of Mesopotamia

1- The first period of human life in prehistoric times was known as the period of food gathering economy, as it depended on gathering wild plants and hunting animals, and made simple tools and machines from stones and animal bones that were used in hunting, and used tree leaves and animal skins to make clothes. As for the second period, the Neolithic era, it was known as the period of food production economy when he learned agriculture and domesticated animals. Agriculture was initially described as meeting the need and was cultivated in small areas and in one season. 2- When he learned the life of stability and lived in permanent villages, the oldest of which is the village of Jarmo, many tools were found made of flint, stone vessels, spoons and pottery. In addition, the village contained permanent houses and clay ovens for making bread, fireplaces, basins, stoves and clay dolls. 3- Domesticating animals, especially goats, sheep and pigs, benefiting from their meat, cheese, skins and fat to make oils, and domesticating dogs. 4- The most important crops that he cultivated were wheat and barley, and later in other areas he cultivated lentils, flax and legumes. 5- In the Stone Age, he learned fertilization and artificial irrigation. He cultivated large areas and had a surplus in production, which prompted him to make large-sized stores to store the surplus, noting that the stores had existed since the era of Hassouna, but they were small. He also learned trade and the barter system and the discovery of metals. Specialization in work and division of labor appeared, and other crafts and professions appeared. The pottery wheel, spinning and weaving discs, and seals were invented. 6- Wool and hair of sheep and goats and some plants such as flax were used to make clothes using spinning discs. 7- Many pottery vessels of different sizes and shapes were found, and they contained drawings, decorations, engravings, and colors of great precision, some of which were made by hand and others with a pottery wheel. Tools and machines were made of copper. 8- Moving to the south and the emergence of large cities, carrying out irrigation projects, and the emergence of the first systems of government. 9- A change and development occurred in the human mind, benefiting from the natural environment and the wealth it contains that could serve him as a result of the development of social , cultural and economic life. 10- Plant cultivation and domestication were coupled with animal husbandry and domestication, as both complement each other in terms of benefit. Because of them, other crafts and professions emerged, including the manufacture of tools and machines, pottery and weaving. Trade also flourished as a result of an increase in the surplus and the increase in labor. 11- Learning how to extract oils and methods of obtaining them from plants and animals which was of great importance because it had multiple uses, especially in cooking, and the demand for it increased in trade. 12- Plant and animal wealth played an important role in its prosperity and economic recovery, as it represented the backbone of the economy of Mesopotamia. 13- Our information about animals and plants came from cuneiform texts and seals that show scenes of hunting animals, scenes of grazing sheep, scenes of ears of wheat and plants, and from murals on the walls of palaces, scenes of barns designated for raising animals, scenes of relief and three-dimensional sculptures that show domesticated domesticated animals, and scenes of hunting predatory animals.

Environmental Valuation of Wastewater Used in Agricultural Production

In recent years, problems related to the adequacy of existing water resources have arisen due to issues such as population growth, rapid urbanization, industrialization, and climate change. Especially in agricultural production where water is used the most, the use of wastewater has become widespread as a solution to this problem. Considering that wastewater may harm the environment due to the substances it contains, it is aimed to make an environmental valuation in this study. In this context, by using the travel cost method used in the valuation of goods without a market, a different approach was brought to this method, as agricultural production is concerned, and an evaluation was made based on producer surplus. In the study, by comparing the agricultural productions with wastewater and well water, 2 hypotheses have been developed about the environmental valuation of wastewater; First, if the producer surplus of agricultural production with wastewater is lower than that of production with well water, there is environmental pollution, and its value is the difference between the two rents. The second hypothesis is that if the producer's surplus with wastewater is high, positive externality will occur as a hypothesis against the negative effects of environmental pollution. By conducting a survey with 125 producers in the research area, the data of 314 parcels in total were included in the analysis, and the producer surplus was calculated by creating the supply function with the regression analysis. As a result of the research, the producer surplus (584.40$) obtained from the agricultural production made by irrigating with wastewater was found to be higher than the producer surplus (553.44$) of the production made by irrigating with well water. In this case, it was concluded that the wastewater irrigated did not affect the environmental pollution, but the positive externality. Although the use of wastewater in agricultural production has made a positive contribution to the economy, it will be beneficial to use it after the necessary treatment processes, considering its harmful effects on human health.

Real Life Application of Consumer and Producer Surplus

In this assignment, we addressed the usage of consumer and producer surplus in various sectors as business sector, medical sector, engineering sector, non profit sector and educational sector. Businesses employ consumer excess to draw in new clients, boost client satisfaction, expand their product offerings, and maintain their position as leaders in their sector. The idea is to determine what advantages consumers can have from purchasing a product and then reduce the price of that product to provide those advantages to them in excess.

From One-Pot to Powerhouse: Al-Fe2O3 Thin Films Coupled with Hexagonal ZnFe LDH for Water Oxidation in Alkaline Environment.

As COVID-19 profoundly affected nations worldwide, there was a significant reduction in gas and electricity consumption, contrasting with the surplus production of oil and gas by companies. This situation has ignited a growing interest in researching alternative green fuels. Electrochemical water-splitting has emerged as a promising avenue for advancing the green hydrogen economy. However, the high costs associated with traditional catalysts have hindered the feasibility of this remarkable method on an industrial scale. Here, this study mainly objects to fabricating an efficient, low cost and stable oxygen evolution reaction (OER) catalyst and our focus has been on refining the morphology to enhance activity levels. The optimized one-pot synthesized 15% Al-doped Fe2O3/ZnFe LDH electrode exhibited a mere 230 mV overpotential to achieve a current density of 10 mA/cm2 with the appreciable Tafel slope of 77 mV/dec, Rct and Cdl values. Theoretical investigations were undertaken to elucidate why the 15% doping concentration serves as a critical threshold limit. Both experimental and theoretical investigations delve into qualitatively accessing activity and durability along with the examination of the electronic, morphological, and magnetic properties of the material.

Development of a stock-specific management procedure for snow crab fishery in the Sea of Japan using conditioned surplus production models in a data-moderate situation

A management procedure (MP) automatically calculates an acceptable biological catch from input data, and its performance is quantitatively evaluated by closed-loop simulations of population dynamics with their uncertainties (operating models). In snow crab in the Sea of Japan, an MP based on survey biomass estimates was adopted by stakeholders, rather than a generic MP recommended for data-moderate Japanese stocks. This was done without quantifying its performance owing to data and resource limitations. This study evaluated the performance of the existing MPs and modified the generic MP through closed-loop simulations with state-space surplus production models (SSPMs) conditioned with actual data. The survey-based MP generally worked well to achieve sustainable catch and biomass but tended to be sensitive to the bias in biomass estimates. The modified MP can be more robust to the bias than the survey-based MP with higher catches than the generic MP. This study demonstrates that, although continuing efforts of collecting composition data are inevitable, SSPM could be used as the conditioned operating models even in data-limited situations to sufficiently represent the stock status and its uncertainty.

Assessment on demersal fisheries status in the FMA 573 under data-limited situation: A combination of statistic and CPUE data as inputs for bayesian surplus production model

Abstract Demersal stock potential, total allowable catch (TAC), and exploitation level status in the FMA 573 were assessed and determined by the National Commission of Stock Assessment (KOMNASKAJISKAN) through Ministerial Decree No. 19/2022. However, the fisheries status, i.e., the biomass level concerning the BMSY and the effort level compared to FMSY, was not completely determined. This study demonstrated the alternative approach to determining fisheries status under limited data. Statistical time series production and existing CPUE data were used to perform the Bayesian Surplus Production Model (cMSY). Based on the results, the stock of demersal fisheries in FMA 573 is overexploited, whereas the F/FMSY and B/BMSY are>1 and <1, respectively. The situation needs concern from all stakeholders. Rebuilding the stock formulation scheme through harvest strategy development for demersal fisheries in FMA 573 must be prioritized to ensure the sustainability of the stock and the fisheries business.

The Red Snapper Fishery in the Eastern Java Sea and Its Fishery Management Recommendation

Abstract For decades, the red snapper fishery has been considered a potential demersal fishery in the east part of Java Sea. The fluctuating fishing effort caused the biomass of red snapper has a fluctuate every year. The study’s goal is to analyze the changing conditions of the red snapper fishery in the east part of Java Sea as a basis for developing management recommendations. The production and efforts data were collected from Brondong Nusantara Fishing Port from 2008 to 2021. The data was analyzed using a non-equilibrium surplus production model and depicted using Kobe Plot to know the change direction of red snapper fishery. The result shows that red snapper fishery in the east part of Java Sea has been overfishing with the abundance of biomass has been overfished. This study’s recommendations for fisheries management are to limit fishing efforts and allowable catch in order to improve the red snapper fishery in the east part of Java Sea.

Determining demersal fisheries status in fisheries management arena (FMA) 712 under data limited situation

Abstract Demersal fisheries in FMA 712 have been established since the early 1950’s, industrialization in demersal fisheries was started on 1970’s with the operation of trawl fleets in Java Sea. The exploitation continued until the 1980s when the Trawl Ban regulation was enacted. According to historical statical data from 1980 the number of demersal fishing fleets are still dominating and endangered the sustainability of demersal fish stock in FMA 712. This study presented alternatives approaches to determining demersal fisheries status in FMA 712 using the Bayesian surplus production model (cMSY) and Length-Based Spawning Potential Ratio (LBSPR). The cMSY analysis was conducted using time series production data and known CPUE represent the area in FMA 712 and the LBSPR model was conducted using the life-history parameters and the length frequency data. The results show that current demersal fisheries condition is overexploited, points of estimation of the Biomass condition based on 1980-2022 data: B/BMSY 0,803, F/FMSY 1,75 and MSY 323.000 ton. Additionally, the spawning potential ratio (SPR) of the dominant demersal fish species (Lutjanus malabarius and Portunus pelagicus) was lower than the limit reference point (<0,20), indicating overexploited. This study demonstrates that alternatives approaches could be applied to limited data fisheries and provide useful and robust recommendations.

Differing Land Use Strategies and Effects in Preexisting Livelihood Systems and Natural Environments of Lower Didessa Valley, Western Ethiopia

The continuous encroachment of highland cultivators into the lower Didessa River Valley in west Ethiopia since the mid-20th century has brought environmental, economic, and social changes. This study aimed to depict land use changes and their subsequent impacts on preexisting livelihoods and the environment. The travelers’ records, structured interviews with the local communities, and various documents were collected and analyzed qualitatively. The study revealed that the intensified systems of surplus production since 1950 have remarkable and distinct historical political ecology features and impacts by displacing preexisting livelihood systems and reshaping the social and environmental settings in the valley. Thus, (re)considering policies and programs is important to realize sustainable development in the valley. Moreover, further multi-disciplinary research is necessary to understand land use systems and the ecological situations of the Mecha Oromo and Nilotes when planning interventions in the valley.

Towards sustainable exploitation of European pilchard (Sardina pilchardus) stocks off West African waters

European pilchard (Sardina pilchardus), herein referred to as “sardine” or “European sardine”, is the most productive and economically important small pelagic fish in the Northwest African waters. Thus far, very little is known about its stock status in the West African region despite the rapid decadal increase in its catch production. The present study provides avenues vital to improving guidance for sustainable species management. In this region, sardine is divided administratively into three stocks (northern: stock N, central: stock A + B, and southern: stock C). Thus, the present study used two Surplus Production Models (SPM) to evaluate sardine's stock status. Sardine's catch and scientific survey biomass data obtained from FAO-CECAF's (Fishery Committee for the Eastern Central Atlantic (CECAF)) latest reports were used in this analysis to fit the SPMs and investigate the effectiveness of the available catch-per-unit-effort (CPUE) trends in setting the total allowable catch (TAC) for sustaining the different sardine stocks in the region. Results from the SPMs indicate that the sardine stock in the north is fished at optimum levels. Meanwhile, the SPMs output based on the scientific survey biomass indices indicated a healthy state for the central and southern sardine stocks. Similarly, the fishery CPUE indices for the central and southern stocks showed similar biomass trends compared to the survey biomass index, indicating healthy stock status. Therefore, in cases where survey biomass index data is unavailable to run stock assessments, this study suggests that sardine fishery CPUEs could be used in SPMs to monitor biomass trends over time and may also provide stock status proxies. Additionally, with rapid climate and other environmental changes, sardine stocks must be regularly monitored with consistent and comparable scientific methodologies and updated fisheries time series data.

Analysis of the Status of Sustainable Utilization and Management of Flyfish (Decapterus russelli) Resources in Pasongsongan Waters, Sumenep Regency using the Walter-Hilborn Model

Flyfish (Decapterus russelli) is a small pelagic fish with a fairly high economic value. Flying fish are the fish with the highest production landed at the Pasongsongan Beach Fisheries Port, Sumenep Regency. In recent years, the production of flying fish in Pasongsongan has continued to decline, excessive fishing activities and an increase in the number of fleets are feared to interfere with the sustainability of flying fish resources. Therefore, sustainable management of flyfish resources needs to be carried out, the purpose of this study is to find out the sustainable potential of flyfish resources, to know the number of catches allowed, and to know the status of the utilization of flyfish resources in Pasongsongan waters. The methods used in this study are quantitative and qualitative methods. The analysis used is a surplus production approach using 3 models, namely the Schaefer model, the Fox model and the Walter-Hilborn model. The results of the analysis using the Walter Hilborn model are a surplus production model that is suitable for use with a maximum catch value (Ymsy) of 2,255 tons and a permissible catch (JTB) of 1,804 tons, the utilization rate of flying fish landed in PPP Pasongsongan is 87% with the utilization status in the Fully Exploited category, where in this condition illustrates that the stock of resources has been exploited by 75-100%. An increase in the number of fishing efforts is not recommended even though the number of catches can still increase because it will interfere with the sustainability of fish resources.