The Economic Threshold With a Stochastic Pest Population: An Application to the European Red Mite

WP 1996-09 August 199

How effective are current household recycling policies? Results from a national survey of U.S. households

This paper analyzes a unique dataset collected during a 2006 national survey of U.S. households to explore the effectiveness of common household recycling policies for metals, glass, and plastics: curbside recycling, drop-off recycling, deposit–refund systems (bottle bills), and marginal pricing for household waste. After estimating either generalized ordered logit or multinomial logit models, we find that the most important determinants of household recycling are people\u27s attitudes toward recycling. Our results also suggest that omitting internal variables (perceived recycling obstacles and benefits as well as moral considerations) may bias policy coefficients. Socio-economic variables are typically not statistically significant, with the exceptions of young adults and of African Americans who tend to recycle less than others. Policies with the largest odds ratios are curbside recycling (which is further strengthened if recycling is mandatory), followed by the presence of drop-off collection centers nearby. Bottle bills are also statistically significant but their odds ratios are smaller, possibly because refunds are relatively small and typically do not change for years. Finally, marginal pricing appears to have a limited impact on recycling. These results suggest avenues for improving household recycling at a time when recycling rates appear to be plateauing

Health benefits and control costs of tightening particulate matter emissions standards for coal power plants - The case of Northeast Brazil.

Exposure to ambient particulate matter (PM) caused an estimated 4.2 million deaths worldwide in 2015. However, PM emission standards for power plants vary widely. To explore if the current levels of these standards are sufficiently stringent in a simple cost-benefit framework, we compared the health benefits (avoided monetized health costs) with the control costs of tightening PM emission standards for coal-fired power plants in Northeast (NE) Brazil, where ambient PM concentrations are below World Health Organization (WHO) guidelines. We considered three Brazilian PM10 (PMx refers to PM with a diameter under x micrometers) emission standards and a stricter U.S. EPA standard for recent power plants. Our integrated methodology simulates hourly electricity grid dispatch from utility-scale power plants, disperses the resulting PM2.5, and estimates selected human health impacts from PM2.5 exposure using the latest integrated exposure-response model. Since the emissions inventories required to model secondary PM are not available in our study area, we modeled only primary PM so our benefit estimates are conservative. We found that tightening existing PM10 emission standards yields health benefits that are over 60 times greater than emissions control costs in all the scenarios we considered. The monetary value of avoided hospital admissions alone is at least four times as large as the corresponding control costs. These results provide strong arguments for considering tightening PM emission standards for coal-fired power plants worldwide, including in regions that meet WHO guidelines and in developing countries

Protection des habitats d'espèces menacées en terres privées: analyse d'instruments et de la politique canadienne

The preservation of biodiversity requires the protection of endangered species' habitats. In Canada, approximately 60% of these habitats are located on private lands. We start by analysing the obstacles to the protection of endangered species' habitats, with special attention to the compensation of private property owners affected by conservation efforts. After briefly reviewing the main measures adopted in Canada to protect natural habitats on private lands, we propose some conservation mechanisms that would not excessively burden public budgets. These measures should be discussed in the next proposal for a Canadian endangered species act. La préservation de la biodiversité nécessite la protection des habitats des espèces menacées. Au Canada, environ 60% de ces habitats sont situés sur des terres privées. Nous examinons la problématique de protection de ces habitats et notamment la question de la compensation des propriétaires privés. Nous analysons ensuite les principales mesures utilisées au Canada pour préserver les habitats naturels, et nous proposons des mécanismes de protection qui permettraient de dédommager les propriétaires terriens affectés tout en limitant les dépenses publiques. Ces mécanismes devraient être discutés lors de la prochaine proposition de loi sur la protection des espèces menacées au Canada.Biodiversité, habitats fauniques, instruments économiques

THE ECONOMIC THRESHOLD WITH A STOCHASTIC PEST POPULATION: A REAL OPTIONS APPROACH

Using real options, this paper formulates an optimal stopping model for applying pest control measures when the density of a pest population varies randomly. A delay between successive pesticide applications is introduced to analyze the farmer’s expected marginal cost of reentry. This model is applied to the control of a foliar pest of apples via a pesticide, and solved numerically. A sensitivity analysis shows that the pest density that should trigger pesticide use can vary significantly with the pest density volatility. Incorporating pest randomness into simple decision rules may thus help better manage the chemicals applied to soils and crop

Harvesting a renewable resource under uncertainty

This paper presents a theory of harvesting that allows for partial harvests and accounts for the risk of extinction, for biological assets with size-dependent stochastic growth. The harvesting decision is formulated as a disinvestment problem in continuous time and generalized Faustmann formulas are derived. The probability of extinction is then analyzed for a wide class of growth functions. An illustration based on the logistic Brownian motion shows that both optimal biomass at harvest and harvest size do not vary monotonically with uncertainty. More generally, this paper illustrates the importance of properly accounting for barriers in stochastic investment problems. (C) 2003 Elsevier B.V. All rights reserved

The density of bounded diffusions

This paper presents a methodology for deriving the closed-form density of diffusions restricted to finite intervals with reflecting or absorbing barriers. Bounded diffusions are useful, for example, in finance, resource economics, or industrial organization. Results are derived for popular diffusions. (C) 2004 Elsevier B.V. All rights reserved

Population Uncertainty and the Timing of an Urban Transportation Infrastructure Investment

This paper analyzes the impacts of stochastic population changes on the timing of an investment that reduces congestion in an open, monocentric city with fixed boundaries. Congestion pricing cannot be implemented, but a welfare-maximizing planner can buy land and build transportation infrastructure. Under certainty, I derive a rule of thumb to evaluate infrastructure investments that corrects a standard benefit-cost analysis. Under uncertainty, I show that relying on a standard benefit-cost ratio could lead to investing in bad projects, or investing prematurely, or ignoring attractive projects because of population barriers and the impacts of the congestion externality on the land market