Reaggregation and firm-level inference in multiplant technologies

We examine conditions under which plant-level data can be used to make firm-level inferences about technology, supply, and demand. Global conditions for such reaggregation involve nonjointness restrictions in both the plant and product dimensions. In the neighborhood of the firm’s fixed overheads, however, restrictions may be eased by appealing to a multiplant generalization of Kohli’s notion of almost nonjointness, which we term “almost reaggregation.” While global conditions for almost reaggregation are the same as for full reaggregation, the local conditions outlined are more easily satisfied. Analysts thus are less likely to commit reaggregation bias when firm-level overheads are constant, and can take advantage of this conclusion through judicious model design.      

Measuring the effects of advertising on green industry sales: a generalized propensity score approach

This article estimates the effects of advertising expenditures on annual gross sales of green industry firms using a quasi-experimental framework. In order to account for potential selection bias, a generalized propensity score and a dose-response function are used to estimate advertising treatment effects. The method used allows us to investigate the relationship between the dose (advertising expenditures) and the response (firm sales). We use data from the National Green Industry Surveys of 2009 and 2014 to conduct the analysis. To further investigate potential heterogeneous advertising effects of the size of the firms, we separate the sample into small firms and large firms, according to their annual gross sales. The results indicate that the magnitude and shape of the response function depend on the size of the firm. For small firms, increasing advertising spending yields to higher sales within a range of advertising spending. Beyond this range, advertising spending increases do not impact sales any more. Thus, small firms’ management should carefully monitor advertising input. For large firms, on the other hand, the current evidence does not support a positive relationship between advertising spending and sales since the marginal treatment effect is insignificant almost over the entire range of adverting spending.     

Hierarchies and Groups in DEA

Conventional applications of data envelopment analysis (DEA) presume the existence of a set of similar decision making units, wherein each unit is evaluated relative to other members of the set. Often, however, the DMUs fall naturally into groupings, giving rise first to the problem of how to view the groups themselves as DMUs, and second to the issue of how to deal with several different ratings for any given DMU when groupings can be formed in different ways. In the present paper we introduce the concept of hierarchical DEA, where efficiency can be viewed at various levels. We provide a means for adjusting the ratings of DMUs at one level to account for the ratings received by the groups (into which these DMUs fall) at a higher level. We also develop models for aggregating different ratings for a DMU arising from different possible groupings. An application of these models to a set of power plants is given.     

输电线路防外力破坏的重点——清理高杆植物

输电线路是电力系统的主要输电介质,通过线路将发电厂生产的原始电能传输到企业或个人用户以供使用。由于输电线路传输距离长远,线路路径会跨越各种不同区域,因此输电线路难免会受到外力的破坏,特别是沿线高杆植物,更容易影响到输电线路的安全运行。针对这一点,文章以高杆植物代表,分析了输电线路防外力破坏的相关问题。     

屋顶花园荷载问题探析

屋顶花园是屋顶绿化的一种特殊形式,而屋面荷载问题则是发展屋顶花园的首要关键问题。本文主要从活荷载和静荷载两个方面阐述了屋顶花园的荷载来源及分类,分析了各类荷载的特点和标准。减少屋面荷载主要从减少静荷载的种植基质重量、优先绿化植物、景观小品的设置规模数量和位置以及排水设施材料等方面入手。     

黑龙江省林药结合立体开发结构

探讨了不同生态立地条件下,结构不同林相及群落组合,合理搭配成近期与远期效益兼顾的林药结合的立体开发结构模式,对促进资源的合理开发利用,贯彻天然林保护工程,实施以副养林,摆脱“两危”困境的积极意义。     

一种新型低纯氧设备的流程设计开发

随着化工市场的发展,个性化空分设备越来越重要,本文就是针对市场的发展,开发的一项针对性比较强的一种流程组织。在将来这种设备会越来越多,这个市场会越来越大。     

电力市场改革背景下火力发电厂安全生产管理研究

伴随社会经济的迅速发展,生产生活发生了翻天覆地的变化,各行业对于电力的需求逐步增加。要想满足人们日益增长的电力需求,就要提高对火力发电厂安全生产工作的重视程度。通过加大安全生产管理力度,助推火力发电厂的持续性经营与发展。在电力工业体制深度变革的关键阶段,电力生产安全的重要性也进一步显现。在电力市场改革的背景下,火力发电厂要想在效益获取和长效运转方面实现平衡,就需要将安全生产管理贯穿全程,做好安全事故的防范与应对工作,顺利达成安全生产管理的目标。     

浅谈钦州花卉产业发展的前景

花卉产业的发展不仅能装点园林城市的美好形象,提高市民精神文化素养,而且能为农村产业结构调整和农民增收,发挥积极而不可替代的作用。建设园林城市要重视花卉产业的研究、引导和扶持,不断壮大我市花卉产业,为我市园林城市的建设提供强大的物质基础和保障。     

探讨火力发电厂环保设备的管理及应用

对于火力发电厂来说,其在日常运行中必须要遵循安全、高效的规范与原则。为满足这一需求,需要保障火力发电厂内相关设备运行的稳定性和可靠性,提高火力发电厂的社会价值与经济效益。如今,随着国家对环境保护工作的重视程度不断提高,火力发电厂内环保设备的管理和应用已经成为社会各界所关注的重点内容。对此,论文主要对火力发电厂环保设备的管理与应用进行分析,以供参考。