Mimako Kobayashi

Stochastic Rangeland Use under Capital Constraints

The stocking density on Kazakhstans extensive rangelands is well below traditional levels. To analyze dynamic flock performance, we develop a stochastic dynamic programming model for livestock systems with stochastic forage production. The model contains continuous five state and 12 control variables, allowing improved characterization of the biophysical relationships and economic tradeoffs inherent in such systems. Most Kazakhstan herders have restricted access to capital. The model indicates that the cost of capital strongly affects flock size and productivity. We conclude that capital constraints are important to explaining the current low stocking density. Improving capital markets in rural areas warrants policy attention.

The economics of fuel management: Wildfire, invasive plants, and the dynamics of sagebrush rangelands in the western United States

In this article we develop a simulation model to evaluate the economic efficiency of fuel treatments and apply it to two sagebrush ecosystems in the Great Basin of the western United States: the Wyoming Sagebrush Steppe and Mountain Big Sagebrush ecosystems. These ecosystems face the two most prominent concerns in sagebrush ecosystems relative to wildfire: annual grass invasion and native conifer expansion. Our model simulates long-run wildfire suppression costs with and without fuel treatments explicitly incorporating ecological dynamics, stochastic wildfire, uncertain fuel treatment success, and ecological thresholds. Our results indicate that, on the basis of wildfire suppression costs savings, fuel treatment is economically efficient only when the two ecosystems are in relatively good ecological health. We also investigate how shorter wildfire-return intervals, improved treatment success rates, and uncertainty about the location of thresholds between ecological states influence the economic efficiency of fuel treatments.

The use of poultry value chain mapping in developing HPAI control programmes

The continuing outbreaks of highly pathogenic avian influenza (HPAI) in Southeast Asia have been disastrous to the poultry industry in the region and have raised serious global public health concerns. Risk for animal and human health exists along the whole poultry value chain. The Food and Agricultural Organisation of the United Nations initiated a series of value chain studies in Asia and Africa during 2007 as a means to develop a better understanding of the trade flows, disease transmission mechanisms and possible entry points for intervention in various value chains. This paper outlines the methodology used to undertake these value chain studies, their use in developing policy and HPAI control measures that decrease animal and human health risks, and describes a value chain study in North Sumatra undertaken by FAO and the University of North Sumatra.

Sensitivity of WTP Estimates to Definition of ‘Yes’: Reinterpreting Expressed Response Intensity

Willingness to pay (WTP) estimation typically involves some strategy for mapping nondichotomous contingent valuation (CV) responses onto a dichotomous yes/no dependent variable. We propose a new approach to selecting which responses qualify as ‘yes.’ We apply the proposed method to polychotomous CV data for preventative land management programs in the Great Basin. We also estimate WTP using other methods of response recoding found in the literature. By contrasting the results under different approaches, we demonstrate how and why WTP point estimates vary across recoding methods and discuss the comparative advantages of our more generalized recoding approach that is based on predicted probabilities of ‘yes’ responses.

Latent Thresholds Analysis of Choice Data under Value Uncertainty

In many non-market valuation settings stakeholders will be uncertain as to their exact willingness-to-pay for a proposed environmental amenity. It then makes sense for the analyst to treat this value as a random variable with distribution only known to the respondent. In stated preference settings, researchers have used elicitation formats with multiple bids and uncertain-response options to learn about individual value distributions. Past efforts have focused on inference involving the expectation of individual densities. This requires stringent and likely unrealistic assumptions regarding the shape or moments of individual value distributions. We propose a Latent Thresholds Estimator that focuses instead on the range, i.e. minimum and maximum willingness-to-pay of individual respondents. The estimator efficiently exploits correlation patterns in individual responses and does not require any restrictive assumptions on underlying values. It also nests some of the existing approaches, which are not statistically supported for our empirical application. Copyright 2012, Oxford University Press.

Optimal Livestock Management on Sagebrush Rangeland with Ecological Thresholds, Wildfire, and Invasive Plants

This article considers optimal livestock management on sagebrush rangeland in the presence of invasive plants, wildfire, and reversible and irreversible ecological thresholds. We find that ranchers operating on healthy rangeland have sufficient private incentive to maintain rangeland health, while ranchers operating on degraded rangeland will pursue rehabilitation only if treatment success rates are improved or treatment costs reduced relative to current levels. We also find that if ranchers do not understand the relationships among grazing pressure, vegetation treatments, and rangeland ecological dynamics, their management will result in higher short-run profits, but lower long-run profits, and greater ecological degradation. (JEL Q24, Q57)