Yield improvements are critical to ensuring food security for a growing world population especially in view of the increasing potential for use of land in biofuel production. Efforts to sustain the impressive rate of past productivity gains, epitomized by such successes as the Green Revolution, are bound to rely on biotechnology innovations such as those responsible for the development of genetically engineered (GE) crops. Some argue that the use of biotechnology can substantially improve yields relative to the trajectory established by traditional breeding in the 20th century. Because U.S. adoption of GE varieties has been very strong since their introduction in the late 1990s, we investigated empirically whether and to what extent the GE technology has improved realized yields. We study this question for nonirrigated U.S. maize (Zea mays L.) and soybean [Glycine max (L.) Merr.] yields over 1964 through 2010, having controlled for local effects, weather, fertilization, and the preexisting (non‐GE) crop improvement trend. For maize we find that GE varieties have increased realized yields, with a stronger gain in the Central Corn Belt (CCB). For soybeans, GE varieties appear to have slightly reduced yields. For both crops we find a strong trend in yield growth, which may have accelerated in recent years within the CCB. However, the combined effects of yield trend and GE adoption are predicted to fall short of the growth rate envisioned by industry projections.
We analyze dynamic private provision of a discrete public good by heterogeneous agents, who differ in terms of their levels of impatience, in a differential game framework. In contrast to the strategic complementarity result for homogeneous individuals, we show that an asymmetric completion Markov perfect equilibrium exists, where the individual contributions and the strategic behaviors depend crucially on an impatience differential: the difference in rates of time preference across groups of individuals. When this differential is insignificant, contributions of both types of individuals are strategic complements. On the other hand, when this impatience differential exceeds a threshold, the contributions of impatient individuals become strategic substitutes, whereas the contributions of patient individuals remain strategic complements. We show that group size has an interesting role to play in the strategic behavior: increasing the number of patient individuals aggravates the incentives to free‐ride by the impatient agents. We also derive a condition under which all the socially beneficial projects get completed in the equilibrium.
We estimate a travel cost model for the George Washington & Jefferson National Forests using an On-Site Latent Class Poisson Model. We show that the constraints of ad-hoc truncation and homogenous preferences significantly impact consumer surplus estimates derived from the on-site travel cost model. By relaxing the constraints, we show that more than one class of visitors with unique preferences exists in the population. The resulting demand functions, price responsive behaviors, and consumer surplus estimates reflect differences across these classes of visitors. With heterogeneous preferences, a group of ‘local residents’ exists with a probability of 8% and, on average take 113 visits.
PurposeThe purpose of this study is to use the framework of stakeholder analysis in a participatory democracy, used in forest management planning, for arriving at the best management option for selected sacred groves of Kachchh. This is achieved by accounting for economic, cultural and ecological values and the resulting outcomes in the complex institutional mechanism. Additionally, this study provides a framework for complex decision-making that characterizes the management of sacred groves involving multiple criteria and options accounting for multiple stakeholders that involve conflicting interests.Design/methodology/approachThe analytical hierarchy process was used to calculate the global priorities of management options using the relative importance of stakeholders, weights of different decision criteria to arrive at the best management practice for selected groves of Kachchh. The global priorities of management options rank management practices based on stakeholders' values and their effects on the choice of management strategy as well as on the potential to attain a compromise between competing interests. For this purpose, survey responses of 141 individuals belonging to seven different stakeholder categories were analyzed. Along with focus group discussions, and personal interviews, a stratified random sampling technique was used to survey respondents.FindingsBased on the global priority weights of the alternatives, it is determined that the restoration management option (guggal is restored by planting new guggal sapplings, cattle grazing is prohibited and high levels of ecosystem goods and services are provided) had the highest score, followed by the preservation management option (grazing is allowed on the periphery, juvenile guggal is preserved and moderate ecosystem goods and services are provided). Therefore, restoration of sacred groves is the best management practice of sacred groves in West Kachchh, offering a compromise between maximizing provision of ecosystem services and economic benefits in terms of allowing cattle grazing.Originality/valueThough there are several studies on best management practices for community-owned forests, irrigation systems, and pasture lands, and the role of local institutions in sustaining these common-pool resources; such studies for sacred groves are absent, despite sacred groves being one of the longest surviving common-pool resources that has sustained it over several decades. This is the first study that uses the framework of stakeholder analysis to arrive at the best management practice for sacred groves. The uniqueness of the study lies in a comprehensive evaluation of ecological–economic–cultural interests of multiple stakeholders toward management of sacred groves.
This review paper highlights the informational requirements for the effective use of environmental policy instruments to achieve ambient standards of pollution in India. A section on the Integrated Urban Air Pollution Assessment Model is attempted to identify data requirements for, and information gaps associated with, using these instruments. We review the available information and identify informational gaps that thwart the realization of ambient standards of environmental quality. In India, command-and-control instruments are arbitrarily used to assign liability without taking cognizance of economic estimates. The available cost–benefit estimates of air and water pollution, combined with air quality modelling for urban areas and water quality modelling, are essential inputs for using environmental policy instruments to ensure compliance with ambient standards. We discuss how to use economic estimates while designing and using economic instruments such as pollution taxes and pollution permits, in addition to command and control.
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