Richard A. Levins

The Whimsical Science

Three interviews, fictitious in varying degrees, are used to explore some fundamental questions of economic methodology. The role of mathematics in economic reasoning, the question of truth in assumptions, and whether rigorous arguments will necessarily lead to important results are examined. The use of models in science is usually justified on grounds of prediction or explanation. The general theme of this paper is that many mathematical models in economics fail on both criteria.

Extension programming for teaching manure management to farmers

livestock manure. Others have had to change practices because of public concerns for water quality. In addition, the ever-expanding size of new livestock facilities makes them much more likely to run afoul of local zoning ordinances because of odor and other aspects of manure storage, handling, and application. The water quality dimensions of manure management are magnified in Minnesota by state-level feedlot regulations that are commonly regarded as being among the toughest in the United States. All farms having over 10 animal units in confinement at any time during the year are included. Individual counties are allowed to

Tenure in Agricultural Economics: A Five-Year Review

Tenure acceptance rates were quite high at agricultural economics departments during 1984–88; 85 percent of all candidates were granted tenure. Half of the 39 departments surveyed here rejected no candidates, and only four departments accounted for almost half of all tenure rejections. More rejections came at the college and campus levels than at the departmental level. There was considerable variation among the tenure documents submitted by departments on most issues including criteria and standards, the definition of service, and the treatment of multidisciplinary work. The continuation of tenure, once granted, was virtually ignored.

Distribution Cost Reduction as an Incentive for Coal Conversion

A linear transshipment model was used to determine the extent to which delivered coal prices could be reduced through gains in efficiency in coal transportation and distribution. Aggregate savings for coal users in southern Minnesota of as much as

Manure Application Planner (MAP): Software for Environmental and Economical Nutrient Planning

10.8 million per year were shown to be possible. It was argued that the savings thus obtained would have the same effect as large direct subsidies to potential coal users in encouraging coal use. A program to reduce delivered coal costs would involve less public funding than subsidies in addition to providing coal delivery by truck to industries not able to receive it by rail. Furthermore, the benefits from reduced coal distribution costs would accrue to all local users, not just those selected for public payments.