The economics of biological invasions

Biological invasions are an economic problem. Invasions are typically the intended or unintended consequence of economic activity. They impose real costs on society, and the risk of invasion depends on human behaviour. Effective control of invasions depends on using the right economic instruments and developing the right institutions. The problem has two special features. The first is that the risks of invasions may be very low, but the potential costs are high. Since they are not reflected in market prices, they are typically ignored. The second is that the control of potentially invasive species is a public good of the "weakest link" variety. Both features indicate a precautionary approach. To deal with the first, I recommend the use of environmental assurance bonds to cover society against the risks of invasive species whilst providing importers with an incentive to research the consequences of their actions. To deal with the second I recommend the development of an institution similar to the Atlanta Centre for Disease Control to provide the information and technical advice required if governments are to act, and a central organisation (involving UNEP, UNDP and the World Bank) to strengthen eradication, control of mitigation campaigns in those countries least able to deal with invasive species.Resource /Energy Economics and Policy,

Conservation and Optimal Use of Rangelands

In previous papers we have considered the optimal mix of biodiversity in semi-arid rangelands, focusing on the steady state. This paper addresses the question of conservation in the optimal use of rangelands. That is, it considers the optimal trajectory of biodiversity change. There are two issues involved in the question of timing. One is the uncertainty associated with the fact that many changes in the flora and fauna of rangelands are 'event-driven'. They depend on stochastic parameters taking particular values before a change of state can occur. A second issue relates to the lag structure of changes. In a system that involves a mix of fast and slow variables, in which the approach to the optimum is not 'most rapid', the optimal trajectory may require the system to remain in an apparently stable intermediate equilibrium for some time before it converges to the optimum state. The paper discusses the role of conservation in the optimal use of rangeland resources.Biodiversity, Rangelands

Environmental Bonds and the Incentive to Research in Activities Involving Uncertain Future Effects

It is intuitive that the difficulty of predicting the future outcomes of present activities will be greater the fewer the historical precedents for those activities. Activities for which there exist no historical precedents have been referred to by Shackle (1955, 1961) as `crucial'. Because there exist no observations of the historical outcomes of Shackle-crucial activities, there is no basis on which to identify their possibl

Income, Consumption and Human Development: Environmental Linkages

human development, consumption, globalization

Policies for the regulation of coexistence between GM and conventional crops

Pollen-mediated gene flow is one of the main concerns associated with the introduction of genetically modified (GM) crops, since growers of GM varieties normally do not take into account its possible impact on conventional and organic growers therefore generating negative externalities. Should a premium for non-GM varieties emerge on the market, 'contamination' with GM pollen would generate a revenue loss for growers of non-GM varieties. The existence of such externalities has led the European Union (EU) to put forward the concept of coexistence in order to guarantee farmers' freedom to plant both conventional and GM varieties without generating economic losses to conventional farmers. The first part of this paper develops a simple economic model analysing the problem of pollen-mediated gene flow as a particular kind of production externality. The model, although simple, provides useful insights into the policy needed to regulate coexistence. Since pollen-mediated gene flow is distance-dependent, the externalities will depend on the spatial structure of GM adoption in the landscape. The second part of the paper, taking GM herbicide tolerant oilseed rape (Brassica napus) as a model crop, uses a Monte Carlo experiment to generate data and then estimate the effect of some important policy variables (i.e. number of GM and conventional fields in the landscape, width of buffer zones and spatial aggregation) on the magnitude of the externality associated with pollen-mediated gene flow. Our results show that buffer areas on conventional fields are more effective than those on GM fields and that the degree of spatial aggregation exerts the largest marginal effect on the externality to conventional growers. The implications of the results for the coexistence policies in the EU are then discussed.coexistence, pollen-mediated gene flow, Monte Carlo simulation, Crop Production/Industries,

Reviews

Introduction to the Law of Employment, Industrial Relations: a Social Psychological Approach, New Zealand and the World: Essays in Honour of Wolfgang Rosenberg, Studies in Conflict: Cases in New Zealand Industrial Relations, Labour Market Economics, The Changing Contours of British Industrial Relations, Workers' Co-operatives: Jobs and Dreams, The Right to Strike, Work and People - an Economic Evaluation of Job Enrichmen

The value of agricultural water rights in agricultural properties in the path of development

This paper estimates the value of water rights in a rapidly urbanizing semi-arid area: Phoenix, Arizona. To do this we use hedonic pricing to explore the impact of water rights on property values in 151 agricultural land transactions that occurred between 2001 and 2005. We test two main hypotheses: (1) that the marginal willingness to pay for water rights is higher in more developed urbanizing areas than in less developed rural areas, and (2) that the marginal willingness to pay for water rights in urban areas is increasing in the value of developed land. We find that the marginal willingness to pay for water rights is highest among properties in urbanized or urbanizing areas where a significant proportion of the land has already been developed. Additionally, we find that the marginal willingness to pay for agricultural water rights is greatest in cities where developed land is most valuable