Policy lessons from spatiotemporal enrollment patterns of payment for ecosystem service programs in Argentina

Payment for ecosystem services schemes (PES) are lauded as a market-based solution to curtail deforestation and restore degraded ecosystems. However, PES programs often fail to conserve sites under strong long-term deforestation pressures. Underperformance, in part, is likely due to adverse selection. Spatial adverse selection occurs when landowners are more likely to enroll parcels with low deforestation pressure than parcels with high deforestation pressure. Temporal adverse selection arises when parcels are enrolled for short time periods. In both cases, financial resources are allocated without having a sizeable impact on long-term land use change. Improving program performance to overcome these shortcomings requires understanding attributes of landowners and their parcels across large scales to identify spatial and temporal enrollment patterns that drive adverse selection. In this paper, we examine these patterns in Argentina’s PES program in Chaco forest, a global deforestation hotspot. Our study area covers 252,319 km². Results from multinomial logistic regression models showed that large parcels of enrolled land and parcels owned by absentee landowners exhibit greater evidence of spatiotemporal adverse selection than smaller parcels or parcels owned by local landowners. Furthermore, parcels managed under land use plans for conservation and restoration are more likely to be associated with adverse selection than parcels managed for financial returns such as harvest of non-timber forest products, silviculture, and silvopasture. However, prior to recommending that PES programs focus on land uses with higher potential earnings, a greater understanding is needed of the degree to which these land uses meet ecological and biodiversity goals of PES programs. We suggest that increased spatial targeting of enrollment, along with enrollment of local landowners and further incentives for land uses that support conservation and restoration, could promote long-term conservation of forest lands.     

机电一体化设备的故障维修特点和可靠性分析

随着我国经济的发展和科学技术的进步,各种机电一体化设备产品也逐渐走进了人们的生活,这就需要相关单位加强对机电一体化设备的故障维修,优化设备性能。为此,论文就机电一体化设备的故障维修特点和可靠性做了简单分析。     

Violation behavior in vertical restraint: Empirical analyses in the case of retail price maintenance

An extensive body of work within the marketing and economics literature has been devoted to studying vertical restraints, yet only a few researchers have investigated the violation behavior of retailers. In this paper, we investigate violation behavior in the context of retailer price maintenance. We investigate this behavior using a unique data set from a subsidy program in China, which includes transaction-level information that shows retail price maintenance (RPM) practices in multiple product categories by multiple manufacturers across multiple markets. The results from our fixed effects regression show that retailer violations are more likely to occur when intra-product competition is high. However, how retailer violation likelihood varies with inter-product competition may depend on the product category. We find that inter-product competition, is negatively associated with the likelihood of violation, for “less popular” product categories in the program such as washing machines, air conditioners, etc., but is positively associated with the likelihood of violation for “popular” product categories such as refrigerators, televisions, and cell phones. Our research provides some of the first empirical evidence about retailer violation behavior under RPM in the world’s largest emerging market by focusing on the relationship between violation behavior and market structure. We discuss the implications for monitoring efforts of manufacturers and regulators.     

数控机床在大学生实践教学中的应用及存在的问题

随着科技和数控技术的不断发展,我们对数控人才的要求和考核标准也在不断的上升,目前的数控人才培养还存在着很多的问题。本文就目前高校在进行数控维修教学和实训中存在的主要问题做了系统的研究和分析,并着重阐述了虚拟数控机床在数控维修不同教学模块中的作用。     

Measuring the effects of preservation on farm profits in a continuous treatment setting

Despite billions of dollars of public appropriations to state purchase of development rights (PDR) programmes, there has been limited evaluation of the effects of these investments on the economic performance of preserved farms. This article estimates dose-response functions to evaluate the effects of enrolment in New Jersey’s PDR programme on farm profitability. The generalized propensity score method in a continuous treatment setting is used to address selection bias arising from voluntary programme participation. Treatment effects are measured across treatment levels to determine whether farm profitability is affected differently across levels of programme participation. Our findings reveal that, relative to unpreserved farms, profit per acre tends to increase along lower treatment levels. The profit per acre of preserved farms in the 1–40% treatment range is, on average, $407 higher than that of unpreserved farms in the full sample. Positive profit differentials averaging between $317 and $472 per acre are also observed in the 1–20%, 1–40% and 1–60% treatment quintiles in the farming occupation sample. We do not observe statistically significant profitability differentials when treatment effects are averaged across all positive treatment values.     

铁路企业股权出资的风险防范

当前，资金难题困扰着大量的铁路企业，新的出资形式将不断步入铁路领域。结合股权出资的特点，重点研究股权出资对“资本制度的三原则”形成的冲击，分析股权出资的潜在风险，提出铁路企业股权出资的运用和风险防范建议。     

Nondiscretionary residential water use: the impact of habits and water‐efficient technologies

Several studies published in the last few decades have demonstrated a low price‐elasticity for residential water use. In particular, it has been shown that there is a quantity of water demanded that remains constant regardless of prices and other economic factors. In this research, we characterise residential water demand based on a Stone‐Geary utility function. This specification is not only theory‐compatible but can also explicitly model a minimum level of consumption not dependent on prices or income. This is described as minimum threshold or nondiscretionary water use. Additionally, the Stone‐Geary framework is used to model the subsistence level of water consumption that is dependent on the temporal evolution of consumer habits and stock of physical capital. The main aim of this study is to analyse the impact of water‐saving habits and water‐efficient technologies on residential water demand, while additionally focusing attention on nondiscretionary uses. This is informed by an empirical application using data from a survey conducted among residents of Brisbane City Council, Australia. The results will be especially useful in the design of water tariffs and other water‐saving policies.     

关于构建企业维稳工作长效机制的思考

基于水务公司稳定发展的基本现状和主要不稳定因素分析,分别从生产经营、党建和人才队伍建设等方面探讨构建企业维稳长效机制的有效途径。     

浅谈高速公路养护存在的问题及解决措施

本文论述了高速公路养护存在的主要问题,并提出一系列解决措施。     

Devising an electronically supported heritage conservation method for the Valley of Flowers in the Indian Himalayas

The Valley of Flowers is a national park in the Himalayan state of Uttarakhand in India that was classified as a world natural heritage site in 1988. Around 1982, its maximum carrying capacity was fixed at 60 persons per day, which has been called excessive by experts and observers, given the extremely fragile and immensely valuable nature of the Valley's heritage. This, in monetary terms, can be put at millions of dollars, and is considerably more viewed in terms of knowledge of breeding medicinal plants in cold climates that are being affected by climate change, which its microclimate and ecology present. Given the state's poor resources and the fact that tourism is one of the most important industries for development and conservation, this research assesses the heritage value of the Valley and develops a programme for conservation, including a computerised program for permits, whose value can easily be raised from the current paltry Rs 150 per person. Accompanied by fallow periods and marketing through the Internet to aim for educated tourists, the program ensures that the maximum carrying capacity of the Valley is never exceeded, thus spreading out the number of tourists over its 3.5-month season, while allowing flexibility in booking for chance groups and small families that can pay more.