Marginal Valuation of Charismatic Species: Implications for Conservation

Most contingent valuation studies focus on total willingness to pay (WTP) as a measure of welfare change. For policy involving species preservation, however, it is important to distinguish between the benefits of preventing a species from going extinct and the benefits of preserving numbers above the minimum viable population (MVP) level. Once MVP is exceeded, marginal WTP becomes relevant. These propositions are illustrated for the case of one charismatic species whose management is much debated, minke whales in the Northeast Atlantic Ocean. It is shown that, for a given estimate of total preservation value, strict conservation and extinction can both be optimal. This finding highlights the importance of collecting marginal values in contingent valuation surveys.     

Comparative costs and conservation of wild species in situ, e.g. orangutans

The extent to which conservation is feasible is constrained by budgets and the financial sacrifice stakeholders are willing to bear. Therefore a possible objective for conserving a species is to minimise the cost of achieving that stated aim. For example, if a minimum viable population (MVP) of a species is to be conserved, the size and type of habitats reserved for this could be selected to minimise cost. This requires consideration of the comparative (relative) opportunity costs of reserving different land types for conservation. A general model is developed to demonstrate this and is applied to the case of the orangutan. In the ecological literature, recommendations for reserving different types of land for conservation have been based on comparisons of either the absolute economic returns they generate if converted to commercial use or on differences in the density of a species they support. These approaches are shown to be deficient because they ignore relative trade-offs between species population and economic conversion gains at alternative sites. The proposed model is illustrated for orangutan conservation.     

Willingness to pay for other species' well-being

Benefit-cost analysis of environmental policies typically focuses on benefits to human health and well-being. For other species, economists have attempted to measure human WTP for changes in the numbers of individuals for different types of wildlife, and to preserve biodiversity. When it comes to humans' WTP for improvements in the quality-of-life for other species, however, the evidence is limited. Morbidity and quality-of-life considerations may be particularly important to the task of valuing non-fatal harm to wildlife in the wake of an environmental disaster. We argue that the other species morbidity-reduction component of WTP should be calculated net of any “outrage” component associated with the cause of the harm. This net WTP is likely to be correlated with the premium that people are willing to pay for chicken products from birds for which the quality-of-life has been enhanced by improved animal welfare measures. This paper uses a conjoint choice stated preference survey to reveal the nature of systematic heterogeneity in preferences for “humanely raised” versus “conventionally raised” chicken. We also use latent class analysis to distinguish between two classes of people—those who are willing to pay a premium for humanely raised chicken, and those who are not.     

VALUATION OF WILDLIFE: REVISING SOME ADDITIONAL CONSIDERATIONS FOR SCOPE TESTS

In this article, we build on previous valuation studies to contribute to the understanding of preferences toward conservation of endangered species elicited via willingness to pay. In particular, we assess the effect of the existence of biological substitutes of local endangered species. We also incorporate biological concepts such as the minimum viable population level into the valuation scenario. Furthermore, the role of ethical and environmental beliefs and their relationship with preferences toward conservation levels are explored. Results are discussed and contrasted with previous studies . ( JEL Q2)     

Measuring Passive Use Value: Pledges, Donations and CV Responses in Connection with an Important Natural Resource

This paper examines monetary valuations of lost passive-use benefits associated with damage to a unique environmental resource – a national park, elicited through contingent valuation, and compares them with actual donations to the same end, where the latter are interpreted as a quasi-market expression of willingness to pay for non-market resource services. The relationships between the two valuation approaches were investigated in the specific context of an environmental episode which damaged a unique natural endowment, Israel's Carmel National Park. The empirical analysis is based on data from two sample surveys; one sample was drawn from the population of people who either pledged or pledged and donated during a fund-raising campaign following the episode, with the proceeds dedicated to rehabilitation or prevention of future episodes; the second sample was drawn from the general population of the country. The results cannot be interpreted as providing unqualified support for the reliability of contingent valuation as a means for obtaining passive use values.     

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.     

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.     

Fertility,income and welfare in an OLG model with regulated wages

We analyse the effects of the regulation of wages in a standard one-sector OLG model of neoclassical growth extended to account for endogenous fertility decisions of households and unemployment benefit policies financed at balanced budget. In contrast with the prevailing literature, which has failed to pay due attention to inter-temporal contexts, our conclusion is that minimum wages may be introduced not only for equity reasons, that is, to increase the income of low-paid workers, but under suitable conditions—i.e., if production is sufficiently capital oriented and the unemployment benefits are high enough—minimum wage legislation might be considered as a source of increased economic performance despite unemployment, i.e. a regulated-wage economy performs better than a market-wage economy. As a consequence, since higher minimum wages raise per capita income together with increasing unemployment, our results imply that a positive correlation between unemployment and long-run income per-capita may exist. Further, the lifetime welfare of the representative generation may be increased as well. Finally, the wage rate may also be treated as a policy instrument for the control of population growth.

Comparative dynamics in a productive asset oligopoly

We build a subgame perfect Nash equilibrium of a common property productive asset oligopoly and analyze separately the impact of a change in the implicit growth rate of the asset and a change in the number of firms exploiting the asset. We show that the steady state level of asset can be a decreasing function of the asset's implicit growth rate. This phenomenon arises when the initial stock of asset is below a certain threshold. In the short-run we show that firms’ exploitation rate can be a decreasing function of the implicit growth rate. We study the impact of a change in the number of firms that share access to the asset. Reducing the number of firms can result, in the long-run, in higher industry production. In the short-run, it can result in an increase of the industry's exploitation and a decrease of the level of the asset's stock.     

EQUIVALENT OPTION PRICE WITH SUPPLY UNCERTAINTY

This paper compares two ex ante measures of the benefits of a project with supply uncertainty: compensating option price, the willingness to pay for a project, and equivalent option price, the willingness to accept to forego a project. The paper shows that compensating option price does not generally rank three or more projects correctly, even when the projects only impose a change in a single good. Equivalent option price, like equivalent variation with certain outcomes, always ranks three or more projects correctly. This paper also presents a method to empirically estimate equivalent option price using estimates of the benefits of certain changes. This approach is practically important so that the same study results can be used to estimate equivalent option price even as new projects are developed or as changes occur in the scientific information regarding the probabilities of various project outcomes. An application of the empirical method estimates the benefits of a policy to improve air and water quality when there is uncertainty about the effectiveness of the policy.     

Moral hazard with bounded payments

We study the moral hazard problem with general upper and lower constraints M on compensation. We characterize the optimal contract and show existence and uniqueness. When minimizing costs for given effort, a principal harmed by M will pay according to M on some range of outcomes; when M reflects limited liability or a minimum wage, the contract is option-like. When the principal also chooses effort, a principal harmed by M might nonetheless never pay according to M. This cannot occur if the cost of inducing effort in the standard principal-agent problem is convex, for which we provide sufficient conditions related to the informativeness of outcome about effort.     

Correcting for the endogeneity of pro-environment behavioral choices in contingent valuation

In contingent valuation studies, observed behavioral choices often enter as independent variables in the willingness to pay function. However, these variables may be endogenously determined when the error term in the behavioral model is correlated with the error term in the willingness to pay model. We investigate the effects of correcting for the endogeneity of a variable, namely membership status in environmental organizations that proxies unobservable characteristics of the respondents. Jointly modeling the membership variable and the willingness to pay response yields an estimate for the effect of the former that contradicts previous findings but is intuitive and agrees with theoretical expectations.     

Measurement of the in situ value of exhaustible resources: An input distance function

We develop a methodology to derive the shadow in situ price of nickel by utilizing an input distance function, which can improve upon previous estimates. Our estimates hold regardless of market power and actual cost minimization. The time path of the shadow in situ price is obtained using annual data for Inco, a nickel company. Empirical results suggest a slightly increasing in situ price of nickel over the period 1947–92, but the dynamic optimality condition does not hold. Comparison with the time path of the in situ price obtained by estimating a cost function indicates a sizable discrepancy between the two time trajectories.     

Flooding risk and housing values: An economic assessment of environmental hazard

Climate change, the ‘boom and bust’ cycles of rivers, and altered water resource management practice have caused significant changes in the spatial distribution of the risk of flooding. Hedonic pricing studies, predominantly for the US, have assessed the spatial incidence of risk and the associated implicit price of flood risk. Using these implicit price estimates and their associated standard errors, we perform a meta-analysis and find that an increase in the probability of flood risk of 0.01 in a year is associated to a difference in transaction price of an otherwise similar house of - 0.6%. The actual occurrence of a flooding event or increased stringency in disclosure rules causes ex-ante prices to differ from ex-post prices, but these effects are small. The marginal willingness to pay for reduced risk exposure has increased over time, and it is slightly lower for areas with a higher per capita income. We show that obfuscating amenity effects and risk exposure associated with proximity to water causes systematic bias in the implicit price of flood risk.     

Perspectives on International Trends and Dynamics in Population and Consumption

There are increasing concerns that global environmental limits may soon be met as a result of increasing numbers of people coupled with increasing consumption of resources. However, the current level and rates of growth in both consumption and population vary systematically among countries grouped according to income levels. Many high income countries have population growth rates at close to replacement levels, but their per capita consumption is consistently several times higher than low income countries. Low income countries need to grow out of poverty and have high population growth rates. Using current population structures for India and the USA in an age-structured demographic model, and simple projections of annual reductions in fertility or consumption per capita over the next 50 years, we show that while reductions in both consumption and fertility are necessary to stabilize impacts, there are short term gains from consumption reductions in high income countries such as the USA, and long term gains from early fertility reductions in growing economies such as India.     

Coexistence of GM and non-GM crops with endogenously determined separation

The possibility that genetically modified (GM) crops may contaminate non-GM crops through pollen-mediated gene flow presents a challenge to coexistence of GM agriculture with conventional and organic farming systems. In this paper an analytical model of coexistence is developed that allows for endogenous derivation of efficient widths and allocation of pollen barriers to limit contamination of non-GM crops. To reflect the uncertainty that surrounds pollen dispersal mechanisms the model contains a stochastic contamination function and safety rule decision mechanism, constraining the level of contamination to remain below a tolerated adventitious presence with a given probability. Two policies are considered and their performance is tested: the tolerance level of adventitious presence, and the allocation of responsibility for implementing coexistence measures to either GM or non-GM farmers. The relative size of GM rents (the value of productivity gains and the non-pecuniary benefits from GM crops), rents for identity preserved non-GM crops (price premiums realised over the GM crop price), characteristics of farms, and possible variation in agricultural landscapes are also taken into account. The findings indicate that conventional adventitious presence tolerances can be met without ex ante mandating large widths of pollen barriers. At the policy level, the findings of this paper are relevant for setting region-specific pollen barriers widths, and/or for establishing institutions that facilitate cooperative coexistence.     

The Value of Household Water Service Quality in Lahore,Pakistan

Most existing literature focuses on the benefits of establishing basic drinking water access for unserved populations, the extensive water supply margin. In contrast, this article examines the intensive margin—the benefits of improving water service to under-served households, a growing population in developing country cities. We use contingent valuation to estimate willingness to pay (WTP) for improved piped water quality and reductions in supply interruptions among a sample of 193 households in Lahore, Pakistan. The distribution of WTP is described using parametric and non-parametric models. Results indicate that households in Lahore are willing to pay about 7.50 to7.50 to 9 per month for piped water supply that is clean and drinkable directly from the tap—comparable to the monthly cost of in-home water treatment, and about three to four times the average monthly water bill for sample households using piped water. Estimates of WTP for reducing supply interruptions are both smaller and more difficult to interpret, since a significant fraction of the estimated WTP distribution for supply improvements is negative. All of our WTP estimates are well below 4% of monthly household income, the World Bank’s benchmark upper bound for affordable water service.     

Ecological discounting

Which rates should we use to discount costs and benefits of different natures at different time horizons? We answer this question by considering a representative agent consuming two goods whose availability evolves over time in a stochastic way. We extend the Ramsey rule by taking into account the degree of substitutability between the two goods and of the uncertainty surrounding the economic and environmental growths. The rate at which environmental impacts should be discounted is in general different from the one at which monetary benefits should be discounted. We provide arguments in favor of an ecological discount rate smaller than the economic discount rate. In particular, we show that, under certainty and Cobb-Douglas preferences, the difference between the economic and the ecological discount rates equals the difference between the economic and the ecological growth rates. Using data about the link between biodiversity and economic development, I estimate that the rate at which changes in biodiversity should be discounted is 1.5%, whereas changes in consumption should be discounted at 3.2%.     

Optimal Growth Models with Bounded or Unbounded Returns: A Unifying Approach

In this paper we propose a unifying approach to the study of optimal growth models with bounded or unbounded returns (above-below). Following our approach, we prove the existence of optimal solutions and show, without using the contraction method, that the value function is the unique solution to the Bellman equation for a particular class of functions. The value function can be obtained by the usual algorithm defined by the operator provided by the Bellman equation. Moreover, following our approach we obtain the recent results of F. Alvarez and N. Stokey (1998, J. Econ. Theory82, 167-189) as well as the well-known results. Journal of Economic Literature Classification numbers: C61, 041.