What Every Conservation Biologist Should Know about Economic Theory

Abstract: The last century has seen the ascendance of a core economic model, which we will refer to as Walrasian economics. This model is driven by the psychological assumptions that humans act only in a self‐referential and narrowly rational way and that production can be described as a self‐contained circular flow between firms and households. These assumptions have critical implications for the way economics is used to inform conservation biology. Yet the Walrasian model is inconsistent with a large body of empirical evidence about actual human behavior, and it violates a number of basic physical laws. Research in behavioral science and neuroscience shows that humans are uniquely social animals and not self‐centered rational economic beings. Economic production is subject to physical laws including the laws of thermodynamics and mass balance. In addition, some contemporary economic theory, spurred by exciting new research in human behavior and a wealth of data about the negative global impact of the human economy on natural systems, is moving toward a world view that places consumption and production squarely in its behavioral and biophysical context. We argue that abandoning the straightjacket of the Walrasian core is essential to further progress in understanding the complex, coupled interactions between the human economy and the natural world. We call for a new framework for economic theory and policy that is consistent with observed human behavior, recognizes the complex and frequently irreversible interaction between human and natural systems, and directly confronts the cumulative negative effects of the human economy on the Earth's life support systems. Biophysical economics and ecological economics are two emerging economic frameworks in this movement.     

Desert Locusts in Africa: a Disaster?

Migrating locusts, especially the desert locust (Schistocerca gregaria), have been feared in Africa for thousands of years as famine-inducing pests. Instead of simply waiting for outbreaks to occur, attempts are being made to take preventive action against these pests. Since the breeding areas of the desert locust are distributed across the entire Sahel region, the Arabian peninsula, Pakistan and India, a gigantic logistical and organizational effort is required. Every year, millions of dollars are spent on these preventive control measures, which are still unable to prevent locust plagues completely. The outbreaks in 1987/88 and 1993/94 are the most recent examples. Exactly how large potential disasters caused by gigantic locust swarms may be and whether the effort and expense involved in preventing them pays off economically has never been systematically investigated. The Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) project, 'Integrated Biological Control of Grasshoppers and Locusts', has attempted to assess, on the basis of the available data, what the costs and potential benefits are and to identify the difficulties involved in developing an effective strategy.