Combined these two effects lead to an unambiguous increase in both crop and ecological damage in the agricultural importer. For the case of a simple production subsidy this suggests that, for agriculture exporting countries, invasion related crop damage serves as an adequate proxy for the sign of ecological and total invasion related damage. However, since more complex policies—for example a combination of subsidies to producers and consumers of agriculture—may instead generate changes in crop and ecological damage of opposite signs, we reiterate our general concern over the use of crop damages as a proxy for total invasion related damages. In this section we discuss the likely consequences of relaxing some of the important assumptions of our model. The distribution of inter arrival times for successive introductions is stationary in this model. More appropriately, perhaps, we can think of the arrival rate as dependent on the number of successful introductions in the past. This would be appropriate, for example, if there was a finite pool of exotic species which was being “whittled away” as introductions became successful. In real life, the pool of exotic species is orders of magnitude larger than, say, the expected number of successful introductions in a given year—suggesting that our approximation of the process as homogeneous with respect to time is appropriate. We have also made several simplifying assumptions concerning the nature of the commodities trade: Home is a small, undistorted economy that does not engage in intra-industry trade. If Home is instead a large country in the market for agricultural goods, then changes in the Home subsidy rate that spur local production also affect world prices. Under general conditions9 it can be shown that an increase in S lowers the world price of agricultural goods if Home initially imports agricultural goods. This price change induces a change in local consumption such that overestimates the magnitude of the change in Home imports: as the world price of agricultural goods falls, Home consumers want to buy more, so Home imports fall by less than the increase in Home production of agricultural goods. Indeed, if the elasticity of import demand in Home’s trade partner is less than unity, Home imports of agricultural goods actually rise with an increase in S.
Interpreting Propositions 2 and 3 in this context reveals that the usefulness of agricultural subsidies as an indirect means of reducing successful introductions of non-native species is limited,ebb flow or even reversed, when prices on world markets are responsive to local policy changes. Finally, suppose that countries engage in intra-industry trade in goods. In such a case, changes in net imports misrepresent the true impacts of trade policy changes since rates of exotic species introductions depend not on net imports but gross imports. For example, while the United States is a net exporter of agricultural goods , its imports of agricultural goods are substantial: $37,755 million in 2000 . Cross-hauling of goods can arise for a variety of reasons, and the implications for the validity of propositions 2 and 3 depends on the underlying source of the cross-hauling. First, agricultural commodities include a large variety of goods, from coffee to corn to vegetables and fruit. Some of these goods the US predominately imports and some of these it predominately exports . Reinterpreting S in our model as a subsidy to a single agricultural industry—corn—and subsuming the non-subsidized sector—coffee—in the Y industry would be sufficient to generalize our model to include such cases. However some goods are both imported and exported, such as vegetables and fruit. Some of this cross-hauling can be explained easily by the fact many countries are geographically large and diverse. For example, although apples are grown in Washington State, it may be cheaper for Alaskans to import them from British Columbia. Cross-hauling derived from this source could also be accommodated easily into our model by making the state, rather than the country, the unit of analysis.As discussed earlier, one of the means by which exotic species impose damage on the host country is through destruction of crops. In the interest of simplicity, throughout this paper we have assumed that industrial mix responds to producer prices but not to net harvest rates, such that producers do not engage in “averting behavior.” Farmers planting more corn and less wheat in response to the establishment of the Russian Wheat Aphid in the United States, or using costly pesticides to combat wheat aphids, are examples of averting behavior.
In an economy in which producers face undistorted—i.e. world—prices such averting behavior would reduce the magnitude of, but not change the sign of, crop damages imposed by biological invasions. If, however, producers initially faced distorted prices then biological invasions may actually generate net benefits to an economy. For example, the provision of subsidized water to agriculture in the US’s southwestern states induces the cultivation of water intensive crops, despite that region’s dry climate. Introduction into that region of a pest that preys on water intensive crops would induce a re-orientation of agriculture away from water intensive crops, offsetting at least to a partial extent the effect of the water subsidies and possibly even raising welfare.10 Of course we do not promote such introductions, as it would be superior to eliminate the inefficient subsidies to begin with. We offer this example merely to re-iterate the point from the literature on environmental double-dividends that pre-existing distortions alter the welfare impacts of policy changes, even possibly to the extent of changing the signs of those welfare impacts.Only a few years ago sustainable agriculture was considered peripheral to conventional agriculture and its institutional framework. Today, however, sustainability programs and efforts have been initiated all over the world and sustainability has become a major theme of many groups, including local and national agricultural research institutions, farmer associations, policy makers, and nongovernmental citizens organizations. This institutionalization is manifest in a number of ways – new books and journals devoted to sustainability; sustainable agriculture research and education programs in many agricultural universities and governmental agencies; organic food laws and certification programs; legislative initiatives that mandate various changes toward sustainability; increased popular consciousness about food safety; and higher sales of organic produce. Yet we shouldn’t let this widespread progress convince us that it is time to close off discussion on the meaning of sustainable agriculture. Too many key questions remain at the core of the sustainability debate.
The most fundamental of these is, “Who and what do we want to sustain?”1 Those within the sustainability movement answer this and related questions differently, based on their various positions in the food and agriculture system. Currently, there are many diverse goals and ideas included in the term “sustainable agriculture.”SUSTAINABILITY IN THE BALANCE This diversity presents an opportunity. As a relatively new concept, sustainable agriculture does not yet reflect a coherent vision of what is possible and preferable in agricultural production and distribution. This emerging discourse on sustainable agriculture thus represents a chance for a fundamental paradigm shift in the way we think about food and agriculture and an opening to develop a comprehensive vision of sustainability. It is important to continue to discuss sustainability’s meaning in this context because, “In adopting certain categories for social inquiry we also adopt a certain view of the social world, of its problem areas and of its fixed points, of the actions it makes available and ways in which their results are constrained.” Thus, the language of sustainable agriculture has a direct effect on our form of practical response and action in sustainable agriculture. How we conceptualize sustainability today will determine the extent to which sustainable agriculture will differ from conventional agriculture in the future.We find there is contention over which sorts of problems can legitimately be called sustainability problems, and there are differing viewpoints on the causes of non-sustainable agriculture. There are disagreements over the vision of sustainable agriculture, primarily over who should be the beneficiaries of sustainability. And there is debate over which strategies and practices will be most effective for developing sustainable agriculture. After discussing these view- points we offer our ideas on how we can begin to reformulate sustainable agriculture.Sustainable agriculture arose as a critique of and an alternative to conventional agriculture. A focus on agricultural sustainability first emerged in the U.S. during the energy crisis of the 1970s as people began to recognize the petroleum dependence of industrialized agriculture. The movement grew in response to the farm crisis of the 1980s and an increasing awareness of agriculturally related environmental problems. The primary problems cited in dominant discourse on sustainable agriculture relate to these crises. “Notable among these problems are the contamination of the environment by pesticides, plant nutrients, and sediments; loss of soil and degradation of soil quality; vulnerability to shortages of nonrenewable resources,plant benches such as fossil energy; and most recently the low farm income resulting from depressed commodity prices in the face of high production costs.”Some would add concerns about pesticides’ effects on consumer and worker health and on wildlife as problems leading to demands for agricultural sustainability.In sustainable agricultural science, the main problem addressed is that of the environment and conservation’s role in maintaining profits: “There is a growing awareness about the need to adopt more sustainable and integrated systems of agricultural production that depend less on chemical and other energy-based inputs. Such systems can often maintain yields, lower the cost of inputs, increase farm profits, and reduce ecological problems.”
While all sustainability advocates address the importance of preserving the environment and natural resources, social issues are less often cited as sustainability problems. For example, although many sustainability advocates are concerned with preserving family farms, the larger issue of systemic economic concentration in food and agriculture is rarely addressed. While the dominant discourse on sustainable agriculture raises important problems, there is a tendency to overlook issues such as hunger, poverty, gender subordination, and racial oppression – problems that also contribute to a lack of sustainability in food and agricultural systems. In general, we find that problems identified in dominant U.S. sustainability perspectives are usually framed without questioning the current economic and social structure within food and agriculture systems.Although the United Nations Food and Agriculture Organization explicitly recognizes the link between socioeconomic and agroecological prob- lems,7 the causes of non-sustainable agriculture are often not discussed in scientific texts on sustainability. Family farm and food safety advocates do, however, provide explanations of the problems they identify. Wes Jackson, for example, criticizes corporate agriculture for the concomitant destruction of the environment and the family farm and blames the lack of an ecological approach for an agriculture characterized by soil loss, fossil fuel dependence, and heavy chemical use.8 Another advocate of family farms, Marty Strange, suggests that “the most serious environmental problems in agriculture are those caused by technologies that make large-scale farming possible, and that sever the rewards of farming from the rewards of stewardship and husbandry.” In the same tradition, Wendell Berry decries the industrialization and mechanization of corporate agriculture and asserts that the current U.S agricultural system is unsustainable because of the continual attempt to get the highest possible production with the smallest number of workers.10 Particularly important for Berry is the erosion of cultural values associated with family farming, such as hard work, respect for place, respect for nature, and commitment to home and community. Food safety advocates cite the failure of government to adequately regulate pesticides 11 and lack of consumer awareness as primary causes of food contamination.We wonder, though, if these causes cited for non-sustainability, such as corporate agriculture, inadequate government regulation, and loss of respect for nature, do not themselves need to be explained. Why has corporate agriculture superseded family farming? Why isn’t an ecological approach standard in agricultural research? Why are environmental regulations insufficient or poorly enforced? In our view, there is a need to examine the relationship between the logic of current political economic structures and the causes of agricultural non-sustainability to find the answers to such questions. What role, for example, does the current mode of agricultural production, based on maximizing short-term profits and foreign exchange, play in causing agricultural problems? We must also examine the connection between non-sustainability and present power and decision-making structures at levels ranging from the individual farm to national policies. Who makes decisions in food and agriculture and who do they represent?