In recent years, consumer demand studies have been used to objectively quantify the value that captive animals place on environmental resources. Considerable progress has been made in the development of effective methodologies to assess what resources are valued under controlled experimental conditions, but few of the findings from these studies have been implemented in commercial husbandry systems. A major obstacle has been the need to maintain internal validity in experimental studies at the possible expense of external validity. Experimental subjects may be poor representatives of commercially kept animals, especially where there is no replication of the animal's experience of commercial physical and social environments. This paper will discuss means of increasing the external validity of consumer demand studies. Firstly, experimental animals should be of representative genotypes, reared under commercial conditions and housed in test apparatus with free access to all of the resources that are normally available under commercial husbandry conditions. As well as providing a long-term closed economy, this allows manipulation of potentially important environmental factors such as prior experience. Secondly, naturalistic tasks should, where possible, be used in preference to abstract operant tasks since they appear to be easier to train animals to associate with rewarding resources, therefore many individuals can be investigated efficiently. Furthermore, naturalistic tasks appear to be less prone to operant bias than artificial tasks and can provide robust measures of value in terms of the maximum price paid for access to resources. Finally, for group-housed species, social costs such as enduring higher stocking densities and/or competition for resources may be an effective means of investigating cost-benefit trade-offs under commercial conditions. For example, if animals work to evenly distribute themselves over available space, this social spacing priority can be used to investigate whether they will endure higher stocking densities in order to exploit particular resources.

This research seeks to determine effects of rising interest in gluten-free foods on U.S. retail food demand and, ultimately, producer and consumer welfare. Increased gluten-free interest led to a modest reduction in cereals and bakery demand and increases in meat, alcoholic beverages, and food away from home demand. Combining estimated effects with an equilibrium displacement model suggests the reduction in cereal and bakery demand decreases wheat and barley producer profits by US$7.2 million/year. After accounting for positive demand impacts on other products, results indicate wheat and barley supply is redistributed away from food production into animal production, increasing wheat producer welfare.

We estimated the economic benefits resulting from controlling soybean aphid infestation by using a multi-regional competitive dynamic equilibrium model. Results indicate that the reduction of soybean production resulting from a soybean aphid infestation is largely absorbed by reducing soybean exports, due to the higher price elasticity of export demand compared to domestic demand. Producer benefits resulting from controlling soybean aphids would increase by between $949 million and $1.623 billion in ten years under various scenarios. Results also suggest that it is economically more efficient to control soybean aphids when the rate of intrinsic growth is relatively lower, the supply price elasticity of soybean acreage is relatively more elastic, and insecticide treatment costs per acre are lower. However, if the discovery of the gene Rag-1 (TF04048) leads to new cultivars that withstand the soybean aphid, our estimates will overestimate the actual damages. Even so, our analysis demonstrates that it is critical to control soybean aphids early in their infestation cycle to avoid a rapid increase in damages.

This paper examines heterogeneity in the preferences for OHV recreation by applying the random parameters Poisson model to a data set of off-highway vehicle (OHV) users at four National Forest sites in North Carolina. The analysis develops estimates of individual consumer surplus and finds that estimates are systematically affected by the random parameter specification. There is also substantial evidence that accounting for individual heterogeneity improves the statistical fit of the models and provides a more informative description of OHV riders.

This study examines per trip consumer surplus associated with guided Whitewater rafting on two southern rivers. First, household recreation demand functions are estimated based on the individual travel cost model using truncated count data regression methods and alternative price specifications. Findings show mean per trip consumer surplus point estimates between $89 and $286, depending on modeling assumptions and river quality. Magnitudes of these surpluses are very dependent on assumptions about the opportunity cost of time.

Although monetary valuation of natural ecosystems is difficult, such valuation helps to draw attention to their importance, and highlight conservation needs, especially in developing countries. The recreational value of Khecheopalri, a lake situated in the West District of Sikkim State, India, which has recreational, biodiversity and sacredness values, was assessed. The demand curve function for recreation increased with decreases in travel cost and distance for Sikkimese visitors. The recreational value of the lake was similar to other protected sites in India; however, all these sites had very low values compared to sites elsewhere in the world. Willingness to pay for maintenance and preservation of the lake by all types of visitors ranged from US$ 0.88 for members of the local community to US$ 7.19 for international tourists. The lake showed high recreational/sacredness values that were attributed to conservation of the site for biodiversity and pilgrimage. A large number of lakes in the Hindu-Kush Himalayan region, if properly managed and marketed for ecotourism, can bring economic development that can be linked with conservation.