| 1. |
- Akpalu, Wisdom, 1968, et al.
(författare)
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Bio-economics of Conservation Agriculture and Soil Carbon Sequestration in Developing Countries
- 2010
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Improvement in soil carbon through conservation agriculture in developing countries may generate some private benefits to farmers as well as sequester carbon emissions, which is a positive externality to society. Leaving crop residue on the farm has become an important option in conservation agriculture practice. However, in developing countries, using crop residue for conservation agriculture has the opportunity cost of say feed for livestock. In this paper, we model and develop an expression for an optimum economic incentive that is necessary to internalize the positive externality. A crude value of the tax is calculated using data from Kenya. We also empirically investigated the determinants of the crop residue left on the farm and found that it depends on cation exchange capacity (CEC) of the soil, the prices of maize, whether extension officers visit the plot or not, household size, the level of education of the household head and alternative cost of soil conservation.
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| 2. |
- Akpalu, Wisdom, 1968, et al.
(författare)
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Bioeconomic model of spatial fishery management in developing countries
- 2010
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Fishers in developing countries do not have the resources to acquire advanced technologies to exploit offshore fish stocks. As a result, the United Nations Convention on the Law of the Sea requires countries to sign partnership agreements with distant water fishing nations (DWFNs) to exploit offshore stocks. However, for migratory stocks, the offshore may serve as a natural marine reserve (i.e., a source) to the inshore (i.e., sink); hence these partnership agreements generate spatial externality. In this paper, we present a bioeconomic model in which a social planner uses a landing tax (ad valorem tax) to internalize this spatial externality. We found that the tax must reflect the biological connectivity between the two patches, intrinsic growth rate, the price of fish, cost per unit effort and social discount rate. The results are empirically illustrated using data on Ghana.
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| 3. |
- Akpalu, Wisdom, et al.
(författare)
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Can the restrictive harvest period policy conserve mopane worms in southern Africa? : A bioeconomic modelling approach
- 2009
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Ingår i: Environment and Development Economics. - 1355-770X .- 1469-4395. ; 14:5, s. 587-600
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Tidskriftsartikel (refereegranskat)abstract
- The mopane worm, which is the caterpillar form of the Saturnid moth Imbrasia belina Westwood, is like other edible insects and caterpillars a vital source of protein in southern African countries. The worms live and graze on mopane trees, which have alternative uses. With increasing commercialization of the worm, its management, which was hitherto organized as a common property resource, has been degraded to almost open access. This paper uses a bioeconomic modelling approach to show that for some optimal allocation of the mopane forest stock, the restrictive harvest period policy advocated by community leaders may not lead to sustainable harvesting of the worm
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| 4. |
- Akpalu, Wisdom, et al.
(författare)
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Connectivity at a cost : The economic dynamics of connectivity restoration
- 2014
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Konferensbidrag (refereegranskat)abstract
- The ecological literature shows that there is a species-area relationship between habitat size and the equilibrium number of species that will thrive in a habitat. There is also a literature on habitat fragmentation showing that, if a larger habitat is broken up into smaller fragments, the long run equilibrium species number will decline in each of the remaining fragments according to the same relationship. Both in the United States and in Europe there is ongoing work on reversing habitat fragmentation in river systems, with fish ladders and other measures being introduced to restore connectivity in river systems that have previously been subdivided into smaller habitats by hydropower and other developments. However, even if connectivity is restored, the new and higher equilibrium species number will be reached only after extended periods of time. This means that measures to restore connectivity entail incurring one-time investment costs (and possibly continuous long run increases in maintenance costs as well) in order to gain habitat improvements that will generate increasing value over time upto the point where the new, better equilibrium is reached. In this paper, we set up a theoretical model to investigate what the conditions are for such an investment to be socially profitable, and link the model to empirical data from measures to restore river system connectivity which show how quickly this recovery tends to occur in practice. We find that even in cases where it would have been socially preferable not to build a hydropower installation in the first place, connectivity-restoring measures affecting the installation are not necessarily socially profitable. Under a wide range of plausible assumptions about discount rates, investment costs and productivity losses, decommissioning the hydropower plant once its economic lifespan is past is a better option, from the social planner’s perspective, than carrying out measures while the plant is still economically viable.
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| 5. |
- Akpalu, Wisdom, et al.
(författare)
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Connectivity at a cost : Economic dynamics of restoring habitat connectivity
- 2021
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Ingår i: Natural Resource Modeling. - : John Wiley & Sons. - 0890-8575 .- 1939-7445. ; 34:1
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Tidskriftsartikel (refereegranskat)abstract
- Both in the United States and in Europe there is ongoing work on reversing habitat fragmentation and the attendant loss in biodiversity in river systems caused by hydropower and other developments. Fish ladders and other measures are being introduced to restore the connectivity in river systems. In this paper, we set up a theoretical model to investigate what the conditions are for such an investment to be socially profitable. We find that, even in cases where it would have been socially preferable not to build hydropower installations in the first place, connectivity-restoring measures affecting the installations are not necessarily socially beneficial. This is the case for a wide range of plausible assumptions about discount rates, investment costs and productivity losses.
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| 6. |
- Akpalu, Wisdom, et al.
(författare)
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Context, welfare sensitivity, and positional preferences among fisherfolks in a developing country
- 2024
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Ingår i: Journal of Behavioral and Experimental Economics. - 2214-8043 .- 2214-8051. ; 108
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Tidskriftsartikel (refereegranskat)abstract
- It is well established in the empirical literature that people care about relative status or positionality. Hence, any policy that makes someone better off imposes a negative externality on their peers. However, the effectiveness of public policy aimed at mitigating positional externality hinges on the drivers of relative concerns, which are individual and context-specific, requiring empirical analysis. This study investigates positional concerns of individuals in artisanal fishing communities in a developing country where the men go on fishing expeditions and the women process and sell the catch, and the specific role of welfare sensitivity in moderating relative concerns. The contexts are formulated as management policies relating to the specific gender roles in fishing. We found that compared to the women, the men were more positional, on average, and relative concerns are context-dependent for both genders. Next, the men had lower welfare sensitivity than the women. For both groups and in a specific context, being welfare-sensitive over a narrow (broader) income range correlates with a relatively higher (lower) degree of positionality.
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| 7. |
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| 8. |
- Akpalu, Wisdom, 1968, et al.
(författare)
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Enforcement of Exogenous Environmental Regulations, Social Disapproval, and Bribery
- 2009
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Many resource users are not directly involved in the formulation and enforcement of resource management rules and regulations in developing countries. As a result, resource users do not generally accept such rules. Enforcement officers who have social ties to the resource users may encounter social disapproval and possible social exclusion from the resource users if they enforce regulations zealously. The officers, however, may avoid this social disapproval by accepting bribes. In this paper, we present a simple model that characterizes this situation and derives results for situations where officers are passively and actively involved in the bribery.
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| 9. |
- Akpalu, Wisdom, 1968
(författare)
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Essays on Economics of Natural Resource Management and Experiments
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis has five self-contained essays. The titles and the abstracts of the various essays are as follows. Paper 1: Natural Resource use Conflict: Gold Mining in Tropical Rainforest in Ghana: Gold is frequently mined in rainforests that can provide either gold or forest benefits, but not both. This conflict in resource use occurs in Ghana, a developing country in the tropics where the capital needed for mining is obtained from foreign direct investment (FDI). We use a dynamic model to show that an ad valorem severance tax on gross revenue can be used to internalize environmental opportunity costs. The optimal tax must equal the ratio of marginal benefits from forest use to marginal benefits from gold extraction. Furthermore, the tax should increase (decrease) when adjusted net return on all other assets in the economy is higher (lower) than the growth in the price of gold. Empirical results suggest that the 3 percent tax rate currently used in Ghana is too low to fully represent the external cost of extraction (i.e., lost forest benefits). Paper 2: A Dynamic Model of Regulatory Compliance in Fisheries: The Case of Mesh Size: This paper employs a dynamic model for crimes that involve time and punishment to analyze the use of nets with illegal mesh size under two management regimes: competitive and regulated open access fishery. The model is based on the consideration that the illegal net is used repeatedly until detection; the net decreases the expected weight recruitment of catchable fish; and lowers the average cost of harvest. We find that under the competitive fishery, the equilibrium stock and harvest are lower if the fishers use the illegal mesh size. However, under regulated open access, the size of the equilibrium stock depends on the ratio of the elasticity of catchability coefficient to the elasticity of the hazard rate. Furthermore, under some condition, the fine for violation should be higher under open access relative to the competitive fishery for any given level of violation. Paper 3: Individual Discount Rate and Regulatory Compliance in a Developing Country Fishery: Studies on compliance with fishing regulations have looked at fishery crimes for which the offender faces a one-period decision problem of maximizing an expected utility. Moreover, the returns to the crimes are uncertain because the offender may lose them if caught. This paper extends these models by considering a fishery crime that generates flow of returns until the offender is caught and then punished. Consequently we incorporate into the existing model, the influence of dynamic deterrence in which the discount rate affects violation levels. The predictions of the model are tested on data from an artisanal fishery in Ghana. Paper 4: Does Ostracism Decrease Over-fishing? A Common Pool Resource Experiment in Ghana: This paper investigates how the presence of ostracism, which is a familiar punishment mechanism to the subjects in an experiment, affects harvest in a common pool resource experiment. The experiment was framed as a fishing problem and the subjects were young fishers in Ghana. We find that the introduction of the possibility to ostracize other members of a group at a cost to the remaining members of the group decreased over-fishing significantly in comparison to the case where ostracism was not possible. Moreover, the subjects demonstrated a strong desire to ostracize those who over-fished. Paper 5: Public Goods and Internalized Norms: This paper links a utility theoretical model based on internalized norms, influenced by Bowles and Gintis (2005), with the results from a novel public goods experiment in Ghana. The results indicate that, on average, people are motivated by conditional cooperation of two kinds: people want to contribute more if others have contributed more in the previous round, and people want to contribute more if others are expected to contribute more. We also found evidence of learning, in the sense that people’s contribution decrease over time even if others’ contribution is held constant.
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| 10. |
- Akpalu, Wisdom, 1968
(författare)
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Natural Resource Use Conflict: Gold mining in tropical rainforest in Ghana
- 2005
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Extraction of gold in many tropical countries is done in rainforests that provide non-timber forest benefit flows. Our model is the first attempt at modelling this conflict in a developing country in the tropics where capital for mining is from foreign direct investment (FDI). We show that ad valorem severance tax on gross revenue from production is efficient if it is equal to the ratio of marginal forest benefit to marginal benefit from gold extraction. Furthermore, the growth rate of the tax is the difference between net return on all other assets in the economy and growth rate of exogenous price of gold. Moreover, the tax is negatively related to the price of gold but has time dependent relationship with discount rate. However, in steady state, it is negatively related to price of gold and discount rate.
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