Daði Már Kristófersson

Geothermal resources support the transition away from fossil fuels and can play an important role in strengthening local energy supply and promoting social development. This paper applies a stochas tic optimization model designed to maximize expected NPV under specified constraints to estimate the optimal development of a geothermal power plant within a hydro-dominated electricity system. Electricity price series are sampled based on varying assumptions about water year variability, with probabilities assigned using historical data. Geothermal resource uncertainty is incorporated through three key stochastic factors with defined probability distributions. A case study of the geothermal f ield in Bjarnarflag in Iceland is used to illustrate the model’s application. Results show that early price spikes increase both expected profits and the optimal initial phase. This effect intensifies with a higher probability of volatile prices. In contrast, price spikes occurring late reduce expected profits and production is reduced. This response is more pronounced for larger initial phases due to higher marginal costs. Compared to fixing production levels at installed capacity, allowing moderate pro duction decreases yields a 29% higher expected NPV primarily by supporting an assertive utilization strategy. A yearly timestep and uniform well cost entails few instances where marginal well cost exceeds prices leading to production decreases. To better capture the benefit of price variations, a more detailed time step and heterogeneous well costs are necessary.

Understanding how fishers react to incentives created by fisheries policy, fish density, and market conditions is essential to understanding and predicting the impact of industrial fishing on the development of marine fish stocks. While most empirical studies focus on demersal species, this study explores the behavior of pelagic fisheries as a recent expansion of Northeast Atlantic mackerel (Scomber scombrus), due to its dynamic geographical nature, brought a new lucrative fishery to Iceland. We fit a spatial choice model for the time period 2011–2020 to understand the importance of environmental and socioeconomic predictors and their impact on individual fisheries behavior. Several models were tested, with the best model predicting 86% of the overall choices correctly. The inclusion of fish price, oil price, vessel size, processing type (frozen/fresh), expected catch, distance to ports, biological parameter of fish density, and environmental parameters such as surface temperature and net primary production played a significant role in improving the model’s accuracy. This highlights the importance of considering both cost-related factors and ecological conditions in understanding fishing location choices.

The bulk of environmental economics literature applies non-cooperative game theory to examine the stability of International Environmental Agreements. Recently, a new trend has emerged in the literature whereby scholars use modified economic approaches to better account for ‘reality’ as such. This article builds upon the work of Hugh Ward, Frank Grundig and Ethan Zorick who conducted a mixed-method analysis to create a model of international climate change negotiations which could explain why policy change has been minimal in this issue area. The purpose of this article is to further develop the mixed-method approach in order to gain a better understanding of international climate change negotiations. Using the progression of the 2011 Durban negotiation session as our raw data, we demonstrate the usefulness of conducting qualitative and quantitative analyses simultaneously to best represent reality. Content and discourse analyses are applied to the Durban negotiations to identify the properties of the underlying game. The results are applied to the future of the negotiations in order to identify trends which need to be addressed to reach more progressive outcomes in the future. The main results of the qualitative analyses of the Durban negotiations included that players had modest expectations at the outset of the negotiations, which influenced the issues they addressed. The quantitative analysis demonstrated that players achieved a high degree of success at Durban; all players achieved their desired outcomes on at least half of the issues they addressed. Finally, the mixed-method approach identified important trends from the negotiations, most importantly the cracks exposed within the BASIC bloc and the role of the ‘middle ground’ alliance.

Lake Victoria, which is shared by Kenya, Tanzania, and Uganda, faces escalating concerns over sustainable fisheries amidst expanding fishing efforts. This study aims to investigate how technical efficiency (TE) and labor productivity (LP) of the Nile perch fishing fleet vary across the three riparian countries. Using a nine-year dataset spanning from 2005 to 2021 and employing Stochastic Frontier Analysis, this study evaluates the TE of the fleet, where LP is determined as catch per crew hour fished in a day for three vessel types: motorized, paddled, and sailed. Motorized fleets had the highest mean technical efficiency (0.60–0.66), compared to paddled (0.29–0.49), and sailed vessel categories (0.24–0.46). Sailed vessels declined in all countries owing to their low TE. In Kenya, TE and LP increased for paddled vessels, especially in the period from 2015 to 2021, and a slight increase was also indicated for motorized vessels. Conversely, Uganda and Tanzania experienced gradual declines in TE and LP, particularly from 2015 to 2021, a period of rigorous law enforcement that led to declines in the number of paddled vessels by 50% and 7%, respectively, and a contrasting increase in motorized vessels. By 2021, the number of Ugandan motorized vessels had increased greatly but TE had declined compared to Kenya and Tanzania, a sign of overcapacity. The findings underscore the need for region-specific policies that address economic differences, policy implementation impacts, and resource health to promote sustainable transboundary fisheries management on Lake Victoria.