|
|
|
|
|
| van Ierland, Ekko C.; Ding, Hongyu; Ruijs, Arjan. |
| In this paper we discuss how a Decision Support System (DSS) for managing the marine environment can be set up. We use the Driving force-Pressure-State-Impact-Respond (DPSIR) framework to analyze which are the major driving forces impacting upon the marine environment in the North Sea. Moreover, a number of potential responses are identified. Furthermore, a preliminary and simplified optimization model has been set up and can be used in a DSS to decide on the best location of marine reserves for the protection of species. The model is based on a bio-economic metapopulation model that can be used to decide which parts of the sea should be opened for fisheries and which should be protected as marine reserve. It accounts for the dispersal of fish and... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Resource /Energy Economics and Policy. |
| Ano: 2007 |
URL: http://purl.umn.edu/10266 |
| |
|
| |
|
|
| Rahim, Afaf H.; van Ierland, Ekko C.; Wesseler, Justus. |
| The gum tree (Acacia senegal) in the Sahel-Sudan zone has many environmental benign functions. An important function is to control desertification. In this paper we analyze farmers' economic incentives to preserve the existing gum trees and their incentives to create new plantations using a real options approach. Results indicate that agricultural crops provide higher economic benefits as compared to gum agroforestry system. However, on the one hand, as gum arabic is produced during the dry period and land is abundant, there are low incentives for deforestation. Instead, farmers' tend to leave the land idle and let the tree growing. On the other hand, our results suggest that an increase in the prices of gum arabic of about 330 per cent is needed to induce... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Gum arabic; Deforestation; Entry and exit; Real options; Sudan; Crop Production/Industries; D4; N5; O13; Q12; Q23. |
| Ano: 2006 |
URL: http://purl.umn.edu/25720 |
| |
|
|
| Chalak, Morteza; Ruijs, Arjan; Hemerik, Lia; van der Werf, Wopke; van Ierland, Ekko C.. |
| Natural enemies such as herbivores that are introduced to reduce invasive plants can spill over into nature, threaten indigenous species and impose significant costs. We develop a bioeconomic model to analyse the optimal control management strategy of an introduced herbivore that has spilled over from a managed system to a natural area. Cost-effective control strategies are analysed that reduce the spillover effects of herbivores on endangered plants species to reduce the risk of extinction and increase benefits obtained from the ecosystem. We consider two competing indigenous plant species as the representatives of the plant community. Only one of these species is consumed by introduced herbivore. We show that the optimal level of controlling herbivores... |
| Tipo: Presentation |
Palavras-chave: Economics; Biological agent; Externality; Spillover; Control; Environmental Economics and Policy. |
| Ano: 2012 |
URL: http://purl.umn.edu/124374 |
| |
|
|
| Otto, Vincent M.; Kuosmanen, Timo; van Ierland, Ekko C.. |
| This study examines whether todays technical change depends on yesterdays technical change. We propose to investigate this feedback effect by using the technical-change component of the Malmquist productivity index. This approach can overcome some problems in alternative patent-citation approaches. We apply the approach by estimating the feedback effect from production data of 25 OECD countries for 1980 through 1997. Our model yields evidence on a positive feedback effect with delays up till eight years. These findings are in line with patent-citation studies and bring us closer to a measure of the social returns to R&D. |
| Tipo: Working or Discussion Paper |
Palavras-chave: Research and Development/Tech Change/Emerging Technologies. |
| Ano: 2006 |
URL: http://purl.umn.edu/12086 |
| |
|
|
|
