Too small to be beautiful? The farm size and productivity relationship in Bangladesh

This paper examines the agricultural productivity-farm size relationship in the context of Bangladesh. Features of Bangladesh’s agriculture help overcome several limitations in testing the inverse farm-size productivity relationship in other developing country settings. A Stochastic Production Frontier (SPF) model is applied using data from three rounds of a household panel survey to simultaneously estimate the production frontier and the technical inefficiency functions. The ‘correlated random effects’ approach is used to control for unobserved heterogeneous household effects. Methodologically, the results suggest that SPF models that ignore the inefficiency function are likely mis-specified, and may result in misleading conclusions on the farm size-productivity relationship. Empirically, the findings confirm that the farm size and productivity relationship is negative, but with the inverse relationship diminishing over time. Total factor productivity growth, driven by technical change, is found to have been robust across the sample. Across farm size groups, the relatively larger farmers experienced faster technical change, which helped them to catch up and narrow the productivity gap with the smaller farmers.     

The Effects of Average Norm Model Regulation: The Case of Electricity Distribution in Sweden

Following the reform of energy sectors, some countries have used engineering norm models in incentive regulation of network utilities. In 2003, Sweden adopted this approach to regulation of electricity distribution networks. This paper examines whether the norm models represent the real networks and create incentives for performance improvement. We analyse data from 138 network concession holders between 2000 and 2007. The results show that norm models are not adequate representations of real networks. Also, utilities that perform better than their norm models tend to behave opportunistically. Finally, we find that private utilities respond more strongly to incentives.     

Profit efficiency among Bangladeshi rice farmers

Production inefficiency is usually analyzed by its three components—technical, allocative, and scale efficiency. In this study, we provide a direct measure of production efficiency of the Bangladeshi rice farmers using a stochastic profit frontier and inefficiency effects model. The data, which are for 1996, include seven conventional inputs and several other background factors affecting production of modern or high yielding varieties (HYVs) of rice spread across 21 villages in three agro-ecological regions of Bangladesh. The results show that there are high levels of inefficiency in modern rice cultivation. The mean level of profit efficiency is 77% suggesting that an estimated 23% of the profit is lost due to a combination of technical, allocative and scale inefficiency in modern rice production. The efficiency differences are explained largely by infrastructure, soil fertility, experience, extension services, tenancy and share of non-agricultural income.     

On Choosing Among House Price Index Methodologies

This paper compares housing price indices estimated using three models with several sets of property transaction data. The commonly used hedonic price model suffers from potential specification bias and inefficiency, while the weighted repeat-sales model presents potentially more serious bias and inefficiency problems. A hybrid model combining hedonic and repeat-sales equations avoids most of these sources of bias and inefficiency. This paper evaluates the performance of each type of model using a particularly rich local housing market database. The results, though ambiguous, appear to confirm the problems with the repeat sales model but suggest that systematic differences between repeat-transacting and single-transacting properties lead to bias in the hedonic and hybrid models as well.     

The speed of the invisible hand

Very little attention has been devoted to incorporating dynamic elements into empirical models of market structure and performance. Consequently, there has been little progress in settling the issue of whether the market structure-profits relationship is more than just a temporary phenomenon. In this study, an estimation equation is developed which allows for incomplete adjustment of past profits from expected future profits, where expected profits depends on present and expected future changes in market structure. The model is estimated pooling panel data across industries. The findings indicate that adjustment to abnormal profits is relatively quick, market share adjustments are non-instantaneous, and that inclusion of industry-specific effects is important. The results suggest that previous studies are susceptible to specification bias from omitted variables.     

Career Concerns,Inaction and Market Inefficiency: Evidence From Utility Regulation

We study how incentive conflicts known as ‘career concerns’ can generate inefficiencies not only within firms but also in market outcomes. Career concerns may lead agents to avoid actions that, while value‐increasing in expectation, could potentially be associated with a bad outcome. We apply this theory to natural gas procurement by regulated public utilities and show that career concerns may lead to a reduction in surplus‐increasing market transactions during periods when the benefits of trade are likely to be greatest. We show that data from natural gas markets are consistent with this prediction and difficult to explain using alternative theories.     

数据挖掘方法在传统预测模型中的应用

数学建模领域中,对于解决不同类型的预测问题有一些经典的预测模型。最近日益流行的数据挖掘技术也有一些针对解决预测问题的独特的数学模型和建模方法。在此对使用传统解析式模型的预测方法与应用数据挖掘技术的数据库模型的预测方法进行了对比,重点分析了2种方法在影响因素的确定、数据规律的寻找方法以及模型侧重点选择上的不同之处,并简单讨论了如何结合2种模型的优点,将数据挖掘技术应用于传统解析式模型的建模过程之中,对已有的解析式预测模型进行改进,进而得出更加可靠准确的预测结果。     

Increasingly Marginal Utilities: Diversification and Free Cash Flow in Newly Privatized UK Utilities

This article was the experience of the newly privatized UK utilities as a unique natural experiment to explore aspects of the life cycle/free cash-flow hypothesis of Dennis Mueller and Michael Jensen. It demonstrates that in their immediate post-privatization, regulated environment the UK utilities experienced severe attenuation of all the principal forms of corporate governance, while remaining substantial cash generators but with limited scope for core business growth. It shows that the firms responded with a rapid – and apparently unsuccessful – expansion of non-core activities. The article then uses a two-way random effects panel design and finds substantial and robust support for the maintained hypothesis that (lagged) cash-flow drove diversification. The results also generate clear implications for privatization policy. In particular, they suggest that the incentive benefits anticipated from substituting private for government ownership may become distorted if the managements of newly privatized enterprises are sheltered from the regular disciplines of corporate governance.     

European consumer preferences for beef with nutrition and health claims: A multi-country investigation using discrete choice experiments

The European Union (EU) nutrition labelling policy aims to facilitate consumers’ food choice, stimulate innovation and facilitate the circulation of foods bearing claims across countries. However, the beef industry has not fully taken advantage of utilizing nutrition and health claims based on the EU nutrition labelling policy to differentiate beef products in the market. This study investigates consumer preferences for nutrition and health claims on lean beef steak. Two choice experiments were conducted among 2400 beef consumers in four EU countries (Belgium, France, the Netherlands, United and United Kingdom). Multinomial logit and error component models were estimated. Our results generally suggest that consumer valuation of nutritional and health claims varies across countries. In Belgium, the Netherlands and France, nutrition and health claims on saturated fat yielded higher utilities than claims on protein and/or iron, while the opposite was found among consumers in the UK. The results imply that marketing opportunities related to nutrition and health claims on beef are promising, but that different nutritional marketing strategies are necessary within different countries.     

基于Logistic组合模型的中国民用汽车保有量预测

经济的发展和人民生活水平的提高使我国民用汽车保有量急速上升,同时导致公共设施和能源供应等矛盾凸显。客观、准确的未来中国汽车保有量预测是解决上述问题的前提。本文以传统Lo-gistic模型为基础,借鉴灰色理论累加生成数据处理方法和级差格式,对预测参数进行估计,同时将模型中扩散速度函数化,并建立以误差标准差为权重的民用汽车保有量的Logistic组合预测模型。该模型能很好地避免传统预测模型中预测参数主观化,预测环境常态化的缺点,使模型能够客观、动态地反映未来中国汽车保有量的扩散趋势。最后结合中国历年民用汽车历史数据,对未来十年中国民用汽车保有量进行预测。预测结果表明:未来十年中国的民用汽车保有量还将快速增长,到2020年中国民用汽车保量将超过2.3亿辆。     

Food prices and the efficiency of public intervention: the case of the public distribution system in India

As public intervention is a pervasive influence on food prices, this paper asks whether and how the inefficiency of state institutions matters to food prices. In the context of the wheat subsidy scheme in India, the paper models the implications of quality differences between public and private grain supply. As both are procured at similar prices, the lower quality of public grain marks the inefficiency of government operations. The paper proposes and empirically validates a method to test for demand switches that occur as a result of quality preference. As a result, a reduction in food subsidies increases food prices and hurts the poor even when they are not major recipients of the subsidy. This seeming paradox is contingent on the inefficiency of public interventions. Thus, the outcome will be different if the reduction in food subsidy were to be accompanied by reforms in the associated state agencies.     

物流需求多样性下的区域物流需求预测研究

在区域物流需求多样性的影响下,对于区域物流需求量的影响因素众多,传统的预测方法和模型对于不同产业结构的区域物流需求预测效果有限。对区域物流需求多样性的特征进行了分析,并在此基础上建立了多产业结构下的SVR预测模型,并利用四川省2000年至2010年实际数据对模型进行了预测和研究,预测的结果表明基于区域物流多样性的预测模型比之不考虑区域物流需求差别的预测更为准确。     

Explaining the Rent–OER Inflation Divergence, 1999–2007

U.S. Rent inflation has often greatly exceeded Owners' Equivalent Rent (OER) Inflation. Why? Critics believe that the Bureau of Labor Statistics is making a faulty utilities adjustment to OER and that the Federal Reserve Board should focus only on Rent inflation. Both beliefs are misguided. Herein we decompose the historical Rent–OER inflation differential into its various determinants. The utilities adjustment, which is necessary, sometimes contributed, but is no smoking gun. The main culprit was an economically interesting pattern of differential rent inflation across locales within cities, one common to many cities. Surprisingly, rent control also played a role.     

Price Effects of Across-State Regulation of U.S. Electric Utilities

Investor-owned utilities (IOUs)serving multiple states are subject to multiple publicservice (utility) commission (PSC) regulation. Focusing on relative rates of an IOU across PSCsisolates regulatory effects. This analysis examines38 such multistate IOUs from 1995. For theresidential-commercial customer comparison, electedPSC commissioners, Republican-appointed commissioners,PSC jurisdiction over municipally-owned utilities (anindirect IOU competitor), and IOU home-state statusare associated with a higher relative rate, whereasmore PSC employees per capita and population densityare associated with a lower relative rate. Thecommercial-industrial comparison results are largelyreversed, but are similarly robust.     

Temporary Agency Work and Firm Competitiveness: Evidence from German Manufacturing Firms

This paper addresses the relationship between the utilization of temporary agency workers by firms and their competitiveness measured by unit labor costs, using a rich, newly built, dataset of German manufacturing enterprises. We conduct the analysis by applying different panel data models while taking the inherent selection problem into account. Making use of dynamic panel data models allows us to control for firm‐specific fixed effects as well as for potential endogeneity of explanatory variables. The results indicate an inverse U‐shaped relationship between the extent that temporary agency workers are used and the competitiveness of firms.     

Can the small dairy farm remain competitive in US agriculture?

Smaller dairy farms in the US are observed to have higher costs than larger farms, and whether those higher costs are due to technology or inefficiency has implications for policy to address the small farm. If high cost of production on smaller farms is due to a higher cost frontier, then to make small farms competitive would require research to devise and design technology that is suitable for small farms. If instead high cost is due to inefficiency, then educational approaches are needed to ensure small dairy farms use technology efficiently. To determine the cause of higher costs on small farms, the cost of milk production by farm size was decomposed into frontier and efficiency components with a stochastic cost curve using data on USA dairy farms. Although the frontier cost of production decreases with farm size, that cost reduction is not as pronounced as a cost curve that includes inefficiency. The higher cost of production on many smaller farms is caused by inefficiency rather than technology.     

木马攻击与防御

特洛伊木马是基于客户 /服务器方式的远程控制程序 ,是黑客的攻击手段之一 ,具有强大的远程控制功能。本文通过对特洛伊木马的基本概念与特征、危害、传播方式、伪装隐藏手段、启动条件、可执行的远程操作等几个方面进行叙述 ,介绍了特洛伊木马的原理 ;对木马的未来发展方向及可能采用的技术进行了探讨 ;最后向读者提出了一些查杀建议     

Ramsey Pricing and Regulator's Social Welfare Weights: An Empirical Application

The paper aims at uncovering the implicit regulator's social welfare weights within a generic Ramsey pricing structure allowing for distinct weights. The methodology is applied to U.S. water utilities for residential and non-residential water services, implying that the weights were virtually identical and thus no cross-subsidies occurred across those goods.     

Vertical disintegration in the European electricity sector: Empirical evidence on lost synergies

The EU has been promoting unbundling of the transmission grid from other stages of the electricity supply chain with the aim of fostering competition in the upstream stage of electricity generation. At present, ownership unbundling is the predominant form of unbundling in Europe. From a policy perspective, a successful unbundling regime would require that the benefits of increased competition in power generation would at least offset the associated efficiency losses from vertical divestiture. Since evidence on this topic is scarce, this study helps fill this void by empirically estimating the magnitude of economies of vertical integration (EVI) between electricity generation and transmission based on a quadratic cost function. For this purpose we employ unique firm-level panel data of European electricity utilities. Our results confirm the presence of substantial EVI of 14% for the median sized integrated utility. Moreover, EVI tend to increase with firm size.     

The involvement of utilities in the development of broadband infrastructure: A comparison of EU case studies

Energy companies and other utility providers have been often involved in the provision of telecommunications services. Nevertheless, their contribution to broadband development has varied significantly over time. In the late 1990s, both local and national utilities in the European Union (EU) engaged in the provision of broadband networks, but only few of them managed to establish themselves as major broadband providers. More recently, new projects involving national utilities have been announced in several EU countries, opening new scenarios for utilities’ contribution to Next Generation Access (NGA) development. This paper identifies and explores the factors affecting the entry and the success of utilities in the EU broadband market, through the comparison of four case studies from four EU countries (Germany, Italy, Sweden and the UK). The evolution of utility involvement in the EU broadband markets is assessed against the interaction of market, technology and policy factors, focusing on the impact of policy and regulatory measures. As a result, this paper provides fruitful insights into the relevance and effectiveness of public interventions in broadband markets. Across the four case studies, public support and public ownership emerged as the main drivers for the involvement of utilities in EU broadband markets, with regulatory measures and economies of scope exerting a limited and decreasing influence. However, the contribution of utilities has varied significantly across the cases studied, reflecting the different approaches taken at national and local level to support broadband development, in spite of the common regulatory framework.