Using choice experiments to value catchment and estuary health in Tasmania with individual preference heterogeneity*

Choice experiments (CE) have become widespread as an approach to environmental valuation in both Australia and overseas. However, there are few valuation studies that have addressed natural resource management (NRM) changes in Tasmania. Furthermore, few studies have focussed on the estimation of estuary values. The CE study described in this paper aims to analyse community preferences for NRM options in the George catchment, Tasmania. Catchment health attributes were: the length of native riverside vegetation; the number of rare native animal and plant species in the George catchment; and area of healthy seagrass beds in the Georges Bay, which was used as a measure of estuary condition. Mixed logit models with interactions between socio‐economic variables and the choice attributes were estimated to account for systematic and random taste heterogeneity across respondents. Results reveal considerable variation in preferences towards the attributes and show that value estimates are significantly impacted by the way in which we account for preference heterogeneity. Preference heterogeneity thus needs to be considered when estimating community willingness‐to‐pay for environmental changes. This study further shows little responsiveness to the presented changes in estuary seagrass area.     

Foot‐and‐mouth disease and the Mexican cattle industry

The objective of this article is to analyze the domestic and international effects of a hypothetical foot‐and‐mouth disease (FMD) outbreak in the Mexican cattle industry. A discrete time dynamic optimization model of the Mexican cattle sector is specified, and linked to domestic and international markets. Economic consequences of FMD outbreaks are simulated over time and under different scenarios. Specific findings and general policy recommendations are provided. The study reports a range of outbreaks from localized to large scale and suggests that changes in economic surplus due to FMD range from a positive net gain of $0.89 to $1.6 billion to a net loss of about $67 billion, depending on the specific mitigation strategy and outbreak scenario.     

关于林权抵押贷款贷款期限的探讨

从林农经济利益角度出发,运用经济分析和数学推理的方法,引入生物生长模型,在分析林木蓄积、林木资产价值和贷款资金的时间价值基础上,确立合理的采伐时间和最佳的采伐时间,进而确立可行的贷款期限和最低贷款期限、最佳的贷款期限。以马尾松为例,进行实际计算分析,得出可行的贷款年限为8～19年,8年为最低贷款年限,19年为最佳的贷款年限。     

Nonparametric Estimation of Oligopsony Power in First‐Price Auction

This paper proposes a nonparametric procedure to estimate market power for first‐price auction data and applies the procedure to cattle procurement markets. Most previous studies have used parametric methods, which require specific functional forms for retail demand, input supply and processors’ cost equations. However, researchers often find that market power estimates from parametric methods are sensitive to the choice of functional forms and specifications. An application to data from cattle procurement experiments shows that our nonparametric approach greatly outperforms commonly used parametric methods in estimating the degree of market power. While parametric estimates are sensitive to functional form specification and are at least 90% smaller than ‘true’ market power indices, estimates from our nonparametric procedure deviate from the actual value by no more than 25%.     

Induced Innovation in U.S. Agriculture: Time-series, Direct Econometric, and Nonparametric Tests

The hypothesis of induced innovation is tested for U.S. agriculture using a high-quality state-level panel data set and three disparate testing techniques—time series, direct econometric, and nonparametric. We find little support for the hypothesis. That conclusion is robust across testing techniques. However, as with all empirical tests of this hypothesis conducted to date, ours focus only on the demand side of the hypothesis. The hypothesis could have been rejected simply because the marginal cost of developing and implementing input-saving technologies for the relatively expensive inputs is greater than for the relatively cheap inputs.     

双星时差频差无源定位系统定位算法工程指标分析

通过计算时差、频差测量精度,以及卫星运动引起的时差、频差变化率,提出双星时差频 差无源定位系统的信号最佳采样时间为10～100 ms。进一步推导了工程可实现的定位精 度,仿真结果表明双星系统工程可实现的定位精度约为1～3 km。研究和结论对双 星定位系统定位精度指标的论证与分解具有借鉴意义。     

城市土地供应年期的合理确定

研究目的:探究如何合理确定城市土地的供应年期。研究方法:现象溯因法、逻辑分析法和对比分析法。研究结果:中国城市土地市场由于土地有偿供应方式的不同,存在出让年期和租赁年期两种模式。土地供应年期直接关系土地配置各方的利益问题,需根据国情和城市经济发展实际灵活确定其合理年限。研究结论:应从城市土地所有者的合法权益、城市土地使用者的合法权益、城市土地利用的社会效益三个角度来分析,灵活确定土地合理供应年期。     

Willingness to Pay for Rural Landscape Improvements: Combining Mixed Logit and Random‐Effects Models

This paper reports the findings from a discrete‐choice experiment designed to estimate the economic benefits associated with rural landscape improvements in Ireland. Using a mixed logit model, the panel nature of the dataset is exploited to retrieve willingness‐to‐pay values for every individual in the sample. This departs from customary approaches in which the willingness‐to‐pay estimates are normally expressed as measures of central tendency of an a priori distribution. Random‐effects models for panel data are subsequently used to identify the determinants of the individual‐specific willingness‐to‐pay estimates. In comparison with the standard methods used to incorporate individual‐specific variables into the analysis of discrete‐choice experiments, the analytical approach outlined in this paper is shown to add considerable explanatory power to the welfare estimates.     

The distribution of returns from land efficiency improvement in multistage production systems

This paper assesses the distributional consequences of technical changes that improve the efficiency of land and of other inputs in a multifactor crop‐production system. We introduced an equilibrium displacement model (EDM) by using the specification of a factor‐augmenting approach. Given the uncertainty about the EDM parameters, a Monte Carlo simulation is used to produce a distribution of possible return measures. We found that land suppliers (likely farmers) receive a larger share (73%) of total benefits from the adoption of land‐technical change than they do from the adoption of other input technologies. Each input supplier receives a larger share of total benefits from technical change in her own input. However, this result is sensitive to the value of the parameters, especially the value of the elasticity of substitution. We applied the EDM to the case of no‐tillage (NT) to provide insight into how the aggregate return from the adoption of NT was distributed among different groups on the Canadian Prairies. The results of this study can be used by policymakers and funding agencies in order to influence landowners and farming communities to adopt environmentally sound land technologies to achieve both greater agricultural productivity and sustainability.     

北京城市家庭水产品在外消费的影响因素分析

本文使用记帐式调查数据,采用Double—hurdle模型分析了北京城市居民家庭水产品在外消费及其影响因素。计量分析结果发现,收入与时间机会成本会显著增加城市居民家庭水产品在外消费的参与概率与消费数量。此外,家庭在外水产品消费的参与和消费决策还受到家庭人口结构与区域分布的显著影响。本文的研究结果对促进我国餐饮业与水产业的健康发展和相关政策的制定有重要意义。