When is a “wait and see” approach to invasive species justified?

Predictions of damages and damages that might be avoided from invasive species control policies are marred by uncertainty that has both economic and ecological roots. Public policies directed at invasive species typically lag their detection. One possible explanation is the coupling of uncertainty with political and economic commitments creates an incentive to delay a policy response in order to gain more information on how damaging the invasion will be – a “wait and see” approach. We investigate whether this rationale is justified by identifying invasion characteristics that require the wait and see approach often adopted by lawmakers and government agencies. The model shows that the source of uncertainty and degree of policy irreversibility matter and allows the classification of invasive species with a low rate of spread and low levels of uncertainty as those where policies can be optimally timed in the future.     

Public economics of hitchhiking species and tourism-based risk to ecosystem services

This paper is the first to examine the public economics of export-based externalities arising within the provisioning of ecosystem services, with direct application to policies to prevent the spread of hitchhiking invasive species. We find when risk enters through exports, policy makers face a tradeoff between welfare improvements and reducing risk of invasion. Estimates of visitor demand elasticity for ecotourism are low, so price policies are not likely to reduce risk, though they can raise tax revenue. If demand is elastic enough to reduce risk, trade effects can cause loss of income greater than the risk of the invasion. The paper is motivated by the expansion of invasive species’ within the United States. We apply our model to the specific example of quagga and zebra mussels invasion into the U.S. Pacific Northwest.     

Importing exotic plants and the risk of invasion: are market-based instruments adequate?

Exotic plant species are often intentionally imported into regions outside of their normal range as ornamental plants or as breeding stock, thereby generating benefits for consumers and producers. However, one of the unintended side effects of such introductions is that the exotic plant species may become invasive. Prohibiting sale of this type of exotic plant species, on the basis that it may become invasive, will have social costs in the form of foregone consumer benefits and nursery profits. We develop a model of a private commercial plant breeding industry that imports an exotic plant species into a region. The risk associated with invasion is modeled using a probabilistic ‘hazard function’, the key determinants of which are the characteristics of the exotic plant and the number of commercial nurseries contributing to its dispersal. We consider the possibility of employing market-based instruments (e.g., Pigovian tax) consistent with the concept of ‘introducers pay’, to regulate the nursery industry. We then provide an empirical illustration using the historical introduction of saltcedar (Tamarisk spp.) into the United States. Our results indicate that the mere presence of a risk of invasion does not mean that it is socially optimal to prevent commercial sales of an exotic plant species. Indeed, there appear to be plausible forms of the functional relationships involved that require only a modest reduction in the private industry optimum. In contrast, no sales of the exotic plant should occur at all under several sets of assumptions about the level of invasion risk and the linkage between dispersal sites and invasion hazard.     

Effects of instantaneous groundwater availability on irrigated agriculture and implications for aquifer management

Groundwater is an important input for agricultural production in many parts of the world. Aquifer depletion has been shown to affect the rate that groundwater can be extracted from an aquifer. In this paper, we develop an analytical framework that accounts explicitly for the effects of limited instantaneous groundwater extraction rate (well capacity) on a producer's irrigation decisions. We show that limited well capacities can affect the producer’s groundwater use and profit. We draw three important insights from these findings. First, we demonstrate that the price elasticity of demand for groundwater is higher for lower well capacities. Second, farmers’ irrigation decisions are non-monotonic with respect to well capacity and climate conditions. Under a drier climate, producers with greater well capacities increase their groundwater use, and producers with lower well capacities reduce their water use. Third, through numerical analysis, we show that considering spatial heterogeneity in well capacities is important for estimating the cost-effectiveness and distributional impacts of groundwater management policies. Our results shed new light on the importance of extraction capacity for groundwater management policies and the potential impacts of climate change on agricultural production.     

How trade politics affect invasive species control

Trade has become the main mode of transport for many invasive species, including diseases and agricultural pests. Most species are brought to their new homes unintentionally, which constitutes a market failure rooted in international trade. Unless it is practical to drive invasion risk to zero, the external costs may justify a tariff. In this paper, we analyze the political process likely to govern the formation of tariffs so justified using a straightforward incorporation of an invasive species externality into Grossman and Helpman's (GH) well-known political economy model. We show that our measure of disguised protectionism—the gap between the optimal tariff and that set in the equilibrium of the political economy game—is equal to the tariff that would be set if there were no invasive species and no international disciplines on trade policy. The informational needs required to distinguish disguised protectionism from legitimate public-goods protection are formidable.     

Quality upgrading in Ethiopian dairy value chains: dovetailing upstream and downstream perspectives

Abstract

In this article, we analyze opportunities and constraints for upgrading product quality in the dairy value chain in Ethiopia. Our analysis is based on an integrated understanding of supply chain performance both from producer and from consumer perspectives. We outline as main drivers for quality upgrading: (a) factors that influence producers’ willingness to invest toward intensification by smallholder dairy farmers and cooperatives and (b) factors that induce consumer’s willingness to pay for healthy and nutritious dairy products delivered at specific retail outlets. Since there are large gaps between upstream producers incentives and downstream consumers motives, possibilities for dairy quality upgrading remain fairly limited. Given this market structure, decisive policy support is required for better tailoring producer’s investments with consumer preferences.     

Tradeable risk permits to prevent future introductions of invasive alien species into the Great Lakes

Commercial shipping has been implicated in over 60% of new introductions of invasive alien species (IAS) in the Great Lakes since 1960, with ballast water being the primary pathway. Recent policies have shifted the focus from postinvasion controls to prevention, with the regulation of oceanic ballast exchange as the primary approach. But this approach is not very effective, and it is often unsafe. We investigate whether an IAS tradeable permit program could provide an efficient alternative, keeping in mind that: (1) not every vessel will actually emit a species, yet ex ante each vessel is a potential emitter; (2) biological emissions are highly stochastic and essentially unobservable given current monitoring technologies. Theoretical issues in the design of a trading program are considered. We then compare the cost-effectiveness of trading versus command and control to reduce the likelihood of invasion by three classes of Ponto–Caspian species that are considered potential invaders capable of causing economic damage in the Great Lakes.     

Modeling the human-induced spread of an aquatic invasive: The case of the zebra mussel

Ecological evidence indicates that transient recreational boating is the principal overland vector of dispersal for several freshwater invasive species. Understanding boating behavior, and how behavior responds to policy changes, is central to understanding the effectiveness of efforts to halt or slow the spread of aquatic invasives. We develop a framework that combines a recreation demand model of boating behavior with a discrete duration model describing the spatial and temporal spread of an aquatic invasive. The integrated approach allows us to link invasion risk probabilities directly to boating behavior, policy levers, and behavior changes arising from policy shocks. With an application to zebra mussels in Wisconsin we show that explicitly accounting for behavioral responses can dramatically change predictions for the effectiveness of particular policies, in some instances leading to increases in invasions risks at some sites.     

An ambient tax approach to invasive species

Invasive species have become an issue of increasing concern in recent years. Invasive species are species that are not native to an area but are imported either intentionally or unintentionally and become established. A primary pathway for introduction is the ballast water of ships. Although not all imported species become invasive, those that do cause extensive damage to ecosystems and have been blamed for the endangerment of numerous native species. In many cases, release of non-native species can be prevented, either through open-ocean ballast water exchange, retention of ballast water, or other biosecurity measures. However, policies designed to encourage such actions face several specific challenges. The difficulty of linking an invasion to a specific vessel and of monitoring individual vessels' care makes using standard environmental liability plans difficult if not impossible. In this paper, we present an alternative policy option, that of an ambient tax. Building on the work of Segerson [Segerson, Kathleen, 1988. Uncertainty and incentives for nonpoint pollution control. Journal of Environmental Economics and Management, 15: 87-98.], we show that an ambient tax can ensure socially optimal behavior in both the short-run and the long-run with minimal vessel specific information.     

Agri-environmental policies in the EU and United States: A comparison

Agri-environmental policies (AEPs) in the United States and the European Union are examples of payments for environmental services that pay farmers to reduce the negative externalities of agricultural production, while serving as a means to transfer public funds to farmers. We show that despite similar origins, AEPs in the two regions differ both in their specific objectives and in their implementation. For example, AEPs in most member states of the EU-15 have the additional objective of using agriculture as a driver for rural development. This objective is achieved by compensating farmers for the private delivery of positive public goods, such as attractive landscapes, produced by agriculture. The rationale is market failure, and there is empirical evidence that Europeans are willing to pay for such positive externalities. No comparable provision exists in U.S. policy. By contrast, U.S. AEPs focus almost entirely on reducing agriculture's negative externalities, such as soil erosion. Second, we find that U.S. programs are more targeted than their EU counterparts, and take opportunity cost into account. The EU programs, on the other hand, address a wider range of externalities, and are focused more on the paying for a particular farming process than reducing specific negative externalities. The EU takes a broader view of AEPs than does the United States, both in terms of type of activity that can be funded, and by using less targeting by land characteristics, and so the European program could be more easily used as a mechanism for transferring income to producers. Despite this, we find evidence that many of the amenities targeted by the programs are demanded by the population.     

The macroeconomic and food security implications of price interventions in the Philippine rice market

The Philippine government has a number of policy interventions in the domestic rice market aimed at promoting national food security. This paper examines the economy-wide and food security implications of three of the main policies: a ceiling on prices paid by rice consumers; a floor on prices received by paddy producers; and a subsidy on prices paid for seeds by paddy farmers. These programmes have been subject to domestic criticism on allocative efficiency and distributional grounds. We examine the effects of removing the programmes using an economy-wide model with detailed treatment of agricultural activity, land use, and food security measures. We find that the programmes make a small contribution to food security, for a modest budgetary outlay. The allocative efficiency gains available from ending the programmes are small, and may be outweighed by the potential for adverse short-run macroeconomic consequences.     

Factors determining awareness and knowledge of aquatic invasive species

Public perceptions of invasive species may influence policies and programs initiated by public and private stakeholders. We investigate the determinants of the public's awareness and knowledge of invasive species as few studies have examined this relationship. We focus on aquatic invasive species (AIS) and employ survey data from property owners in a lake district. A major contribution is that we estimate a mixed trivariate binary-ordered probit regression model that accommodates correlations among unobserved characteristics, produces statistically more efficient estimates, and allows a more proper investigation of the probability of knowledge conditional on awareness. Our results provide insights for invasive species education and management programs. We find that individuals are more likely to be aware of AIS if they participate in water-based recreation, visit lakes outside their area, have a boat, belong to a lake association, or are college educated. This has a policy implication: Given high levels of AIS awareness by those most involved in activities around lakes and those with a higher education, it may be beneficial to target informational campaigns at those who do not display these characteristics, so that they can better make informed decisions about whether to support and expend money on invasive species management programs.     

Species Invasion as Catastrophe: The Case of the Brown Tree Snake

This paper develops a two-stage model for the optimal management of a potential invasive species. The arrival of an invasive species is modeled as an irreversible event with an uncertain arrival time. The model is solved in two stages, beginning with the post-invasion stage. Once the arrival occurs, the optimal path of species removal is that which minimizes the present value of damage and removal costs plus the expected present value of prevention costs. An expenditure-dependent, conditional hazard rate describing species arrival is developed based on discussions with natural resource managers. We solve for the optimal sequence of prevention expenditures, given the minimum invasion penalty as just described. For the case of the Brown Tree Snake potentially invading Hawaii, we find that pre-invasion expenditures on prevention are inverse U-shaped in the hazard rate. Efficient prevention should be approximately $2.9?million today and held constant until invasion. Once invasion occurs, optimal prevention requires $3.1?million annually and $1.6?million per year on species removal to keep the population at its steady state level, due to high search costs at very small population levels.     

Fuel Efficiency Improvements: Feedback Mechanisms and Distributional Effects in the Oil Market

We study the interactions between fuel efficiency improvements in the transport sector and the oil market, where the efficiency improvements are policy-induced in certain regions of the world. We are especially interested in feedback mechanisms of fuel efficiency such as the rebound effect, carbon leakage and the “green paradox”, but also the distributional effects for oil producers. An intertemporal numerical model of the international oil market is introduced, where OPEC-Core producers have market power. We find that the rebound effect has a noticeable effect on the transport sector, with the magnitude depending on the oil demand elasticity. In the benchmark simulations, we calculate that almost half of the energy savings may be lost to a direct rebound effect and an additional 10% to oil price adjustments. In addition, there is substantial intersectoral leakage to other sectors through lower oil prices in the regions that introduce the policy. There is a small green paradox effect in the sense that oil consumption increases initially when the fuel efficiency measures are gradually implemented. Finally, international carbon leakage will be significant if policies are not implemented in all regions; we estimate leakage rates of 35% or higher when only major consuming regions implement fuel economy policies. Non-OPEC producers will to a larger degree than OPEC producers cut back on its oil supply as a response to fuel efficiency policies due to high production costs.     

A proactive approach for assessing alternative management programs for an invasive alien pollinator species

Most evaluations of the economic impacts of invasive species are done post facto and concentrate on direct production loss caused. However, the effects of invasive species on non-market services such as biodiversity and landscapes can be considerable. A proactive approach of assessing the expected economic impact of invasive species prior to their occurrence may contribute to greater efficiency of policy makers. Here we used a stated preference method for a priori evaluating the willingness of the population to pay for different control programs of a new invasive bee species in Israel, the dwarf honey bee, Apis florea. We evaluated possible economic impacts of A. florea using two model plant species expected to be adversely affected by its invasion due to decreased pollination. The plants have no market value but they add aesthetic value to the open landscape. Using a mixed logit model we found that the mean willingness to pay (WTP) differed between the model plants, and increased with the extent of plant loss. Respondents differentiated between levels of damage to the plants and between control methods in their preferences for a specific program. Our results provide means for informed proactive decision making in preventing the continued invasion of the bee.     

Invasive species management in a spatially heterogeneous world: Effects of uniform policies

The spread of invasive species (IS) is an inherently spatial process, and management of invasive species occurs over spatially heterogeneous regions, but policy constraints can restrict management responses to be homogeneous across regions. Using a spatial bioeconomic model that includes a representation of invasive species ecology based on heterogeneous environments that are linked across space and time by human and ecological pathways, we compare optimal spatially heterogeneous policy to spatially uniform policy. We explore the magnitude and pattern of the policy differences with emphasis on the influence of different types of underlying heterogeneity across locations.     

Spatial Management of Invasive Species: Pathways and Policy Options

In addressing the problem of invasive species, decision makers have a variety of options, each targeting different aspects as it evolves over time and space. We develop a 2-region bioeconomic model that includes several transmission pathways that spread the invader. Within each region, inspections, removal efforts, and sustainable land management practices, including habitat restoration and less damaging production activities, are available to the regulator. We investigate the implications of different transmission pathways and second-best policies on the control patterns and invasive populations. Second-best settings where certain controls are not available to the regulator result in large distortions on the optimal use of the land. Overall, we find that non-linear interactions between regions, pathways, and controls are significant determinants of the optimal management of invasive species.     

当前统筹城乡发展中的八个重大问题

文章认为,在统筹城乡发展的过程中,粮食安全是实现统筹城乡发展的基础;城乡居民收入差距是否缩小是衡量推进城乡一体化政策措施正确与否的根本标准;中国现代农业发展的主体应该是以专业合作社形式组织起来的农民;农村金融体制改革的重点应放在发展农民之间的资金互助上;宏观调控必须遵循价值规律公平调控;地方政府绝不能与民争利;不断加大对农业和农民的补贴应作为今后"三农"政策的基本导向;农村社区化的本质是要让农民与市民一样过上现代文明的幸福生活,而不是要化掉村庄。     

The Control of Invasive Species on Private Property with Neighbor-to-Neighbor Spillovers

Invasive pests cross property boundaries. Property managers may have private incentives to control invasive species despite not having sufficient incentive to fully internalize the external costs of their role in spreading the invasion. Each property manager has a right to future use of his own property, but his property may abut others’ properties enabling spread of an invasive species. The incentives for a foresighted property manager to control invasive species have received little attention. We consider the efforts of a foresighted property manager who has rights to future use of a property and has the ability to engage in repeated, discrete control activities. We find that higher rates of dispersal, associated with proximity to neighboring properties, reduce the private incentives for control. Controlling species at one location provides incentives to control at a neighboring location. Control at neighboring locations are strategic complements and coupled with spatial heterogeneity lead to a weaker-link public good problem, in which each property owner is unable to fully appropriate the benefits of his own control activity. Future-use rights and private costs suggest that there is scope for a series of Coase-like exchanges to internalize much of the costs associated with species invasion. Pigouvian taxes on invasive species potentially have qualitatively perverse behavioral effects. A tax with a strong income effect (e.g., failure of effective revenue recycling) can reduce the value of property assets and diminish the incentive to manage insects on one’s own property.     

外来入侵物种的法律规制

外来物种入侵已经成为世界各国面临的严峻问题,外来入侵物种对生物多样性、社会经济以及人类健康造成了严重的危害,国际上对建立预防和控制外来入侵物种的法律制度取得了许多成功的经验。我们应当在借鉴这些经验的基础上,以人与自然和谐发展的环境观和可持续发展观为指导,通过完善环境风险评估、行政许可、名录、检验检疫以及法律责任追究制度来加强外来入侵物种的法律规制。