Uri Regev

Pests as a Common Property Resource: A Case Study of Alfalfa Weevil Control

Recently, problems in pest management have attracted considerable attention in economic literature. This paper describes an economic optimization model that incorporates detailed biological input specific to the alfalfa weevil. The problem is examined from a societal point of view and recognizes specific common property characteristics of the pest. The major discrepancy between the results obtained here and current practices involves the timing of pesticide application. These results indicate the advantage of applying pesticide prior to the growth season, specifically the time period in which the number of adult pests reaches its peak. In the long run each farmer is affected by the cumulative effects of individual decisions. The pest constitutes a common property resource, and a nonregulated market would not yield the optimal solution. The optimal societal solution could be implemented by an information agency, which would enhance cooperation between farmers.

On the optimal allocation of pesticides with increasing resistance: The case of alfalfa weevil

Abstract The problem of pesticide application under increasing pesticide resistance is explored. A theoretical model is developed to determine optimal pesticide use. This allocation is compared to the laissez-faire solution and to the centralized solution with incomplete information about pesticide resistance. The methodology is then applied in a case study on the Egyptian alfalfa weevil in California.

Biological and economic foundations of renewable resource exploitation

Abstract A physiologically based population dynamics model of a renewable resource is used as the basis to develop a model of human harvesting. The model incorporates developing technology and the effects of market forces on the sustainability of common property resources. The bases of the model are analogies between the economics of resource harvesting and allocation by firms and adapted organisms in nature. Specifically, the paper makes the following points: (1) it shows how economic and ecological theories may be unified; (2) it punctuates the importance of time frame in the two systems (evolutionary versus market); (3) it shows, contrary to prevailing economic wisdom, how technological progress may be detrimental to resource preservation; (4) it shows how the anticipated effects of high discount rates on resource use can be catastrophic when synergized by progress in harvesting technology; (5) it suggests that increases in efficiency of utilization of the harvest encourages higher levels of resource exploitation; and (6) it shows the effects of environmental degradation on consumer and resource dynamics. The model leads to global implications on the relationship between economic growth and the ability of modern societies to maintain the environment at a sustainable level.

Fungicide use under risk in Swiss wheat production

The short-run effects of fungicide application on economic risk and the effects of risk on fungicide use in Swiss wheat production are empirically explored. A quadratic production function model is developed. With the help of the moment-based approach, marginal contributions of fungicides (representing controlled inputs) and of rain (representing uncontrolled inputs) to the variances of yield and revenue are analyzed. It is not possible to show risk-reducing effects of fungicides on yield or revenue. At low rain quantities during the vegetation period fungicides have a statistically significant risk-increasing effect on revenue. Increasing risk leads Swiss wheat growers to use more fungicide. This increase is statistically significant at higher levels of revenue. For example, when risk is doubled fungicide inputs are raised by 44% at the highest revenue quartile.

Optimal mining of a stratiform phosphate field

Abstract An optimal control model is developed to determine optimal surface mining operations of a phosphate field. This field1806 1040 contains both a bottom layer and a top layer of phosphates. The deeper the digging, the more phosphates will be exploited but the higher will be the cost per ton. If the bottom layer is not exploited, it will be lost to future production. The methods of Optimal Control Theory are applied and produce expressions which can be evaluated for the optimal scheduling around the phosphate field.

Financial risk of project's cost

In this paper we will examine the effects of uncertainty of investment costs on the expected gain and budget allocation of a decision-maker. These effects are studied using the relationship between riskiness and stochastic dominance. Results and examples are provided for the case of budgeting one project. Furthermore, the problem of centralized vs. non-centralized budget allocation forn identically independent distributed projects is discussed.