ESTIMATION OF EFFECTIVE RISK REDUCION THROUGH IRRIGATION OF A PERENIAL CROP*

This paper outlines an approach to assessing the benefits from in vestment in the irrigation of tea stands in three areas of East Pakistan. Irrigation aflects both the establishment and productive life of the growing crop, and therefore the analysis includes a discounred assessment of the replacement decision, as well as an appraisal of the change in technology. Since the biological and weather eflects that determine annual and long-run productivity of the stand are stochastic variables, the evaluation is made using a simulation model in which these determinants are introduced as known discrete probabilities. Using this model an estimate may be made of rhe net gains to a tea estate of the risk reduction achieved by eliminating harmful crop moisture deficits.     

On dichotomous choice contingent valuation data analysis: Semiparametric methods and Genetic Programming

The aim of this paper is twofold. Firstly, we introduce a novel semiparametric technique called Genetic Programming to estimate and explain the willingness to pay to maintain environmental conditions of a specific natural park in Spain. To the authors’ knowledge, this is the first time in which Genetic Programming is employed in contingent valuation. Secondly, we investigate the existence of bias due to the functional rigidity of the traditional parametric techniques commonly employed in a contingent valuation problem. We applied standard parametric methods (logit and probit) and compared with results obtained using semiparametric methods (a proportional hazard model and a genetic program). The parametric and semiparametric methods give similar results in terms of the variables finally chosen in the model. Therefore, the results confirm the internal validity of our contingent valuation exercise.     

Impacts of price and exchange rate policies on pesticide use in the Philippines

Pesticide prices can influence producer decisions to apply pesticides as opposed to nonchemical means of pest control. Those prices are are turn influenced by price and exchange rate policies. The effective rate of protection for nine pesticides commonly applied to vegetables in the Philippines was calculated to determine whether government policies are creating incentives or disincentives to adopt more integrated pest management methods. Calculations found that direct price policies, primarily through an import tariff, tax pesticide use while an overvalued exchange rate subsidizes pesticide use. The net effect is a 6 to 8% pesticide subsidy. This subsidy results in economic surplus gains to vegetable producers and consumers when negative externalities associated with pesticide use are not accounted for. However, recent analysis of human health effects of pesticide use on rice in the Philippines demonstrates that these externalities can be substantial.     

The future of the uplands

Upland areas provide UK society with many important functions, goods and services, but have experienced a number of disturbing trends and face an uncertain future. This paper outlines historic, current and future drivers of environmental, economic, socio-cultural and policy change in UK uplands, and assesses how these have affected or are likely to affect ways in which land is used and the provision of ecosystem services. Information is synthesised into scenarios summarising a range of possible futures anticipated for UK uplands to 2060 and beyond. Finally, innovations in science, technology, governance and policy are evaluated that could enable uplands to continue providing key ecosystem services under a range of scenarios. The paper concludes that many upland areas will need to be prepared for significant reductions in grazing and prescribed burning. Conversely, other areas could experience agricultural intensification, for example significant increases in grazing or an expansion of arable or bioenergy crops into upland valleys, due to anticipated increases in global demand for food and energy. These scenarios will take place in the context of climate change. Many may take place together and may interact with each other, with complex and unpredictable implications for the upland environment, economy and society. In this context, a number of advances are needed in science, technology and policy to maintain viable upland communities and the future provision of ecosystem services. These may include funding for ecological and hydrological restoration via carbon offsetting or other means. It may also involve advances in ecosystem service modelling, mapping and valuation, which through stakeholder participation could facilitate more integrated rural planning. New forms of environmental governance need to be explored that can empower those interested in developing upland economies to maintain thriving upland communities, while managing the ecosystem services they provide as efficiently as possible.