APPLICATION OF PANEL DATA MODELS IN BENCHMARKING ANALYSIS OF THE ELECTRICITY DISTRIBUTION SECTOR*

ABSTRACT ** : This paper explores the application of several panel data models in measuring productive efficiency of the electricity distribution sector. Stochastic Frontier Analysis has been used to estimate the cost‐efficiency of 59 distribution utilities operating over a nine‐year period in Switzerland. The estimated coefficients and inefficiency scores are compared across three different panel data models. The results indicate that individual efficiency estimates are sensitive to the econometric specification of unobserved firm‐specific heterogeneity. This paper shows that alternative panel models such as the ‘true’ random effects model proposed by Greene (2005) could be used to explore the possible impacts of unobserved firm‐specific factors on efficiency estimates. When these factors are specified as a separate stochastic term, the efficiency estimates are substantially higher suggesting that conventional models could confound efficiency differences with other unobserved variations among companies. On the other hand, refined specification of unobserved heterogeneity might lead to an underestimation of inefficiencies by mistaking potential persistent inefficiencies as external factors. Given that specification of inefficiency and heterogeneity relies on non‐testable assumptions, there is no conclusive evidence in favour of one or the other specification. However, this paper argues that alternative panel data models along with conventional estimators can be used to obtain approximate lower and upper bounds for companies' efficiency scores.     

Regulatory design and technical efficiency: public transport in France

The provision of local public transport in France involves private and public firms and the use of incentive contracts to regulate them. We study the effect of these institutional features on the sector’s efficiency using a long panel data of firms, with a two-stage estimation procedure. First, we use nonparametric data envelopment analysis techniques to estimate input usage efficiency, following a conditional approach that controls for differences in the environments in which the firms operate. Second, we estimate semiparametric censored regressions, using fixed effects to control for unobserved sources of heterogeneity. Our results point to a differential effect of private and mixed public-private companies. In particular, having the performance of public operators as the benchmark, efficiency is relatively higher for private firms, but lower when the service is delegated to a mixed public-private firm. In the latter case, the effects diverge by contract type: when the contract is of the cost reimbursement type, performance is lower than the public firm benchmark, while for other contract types, there are no statistically significant differences.     

Efficiency in International Trade with Firm Heterogeneity and Networks

This paper examines integrated effects of firm heterogeneity and communication network services on international trade. Patterns and effects of trade are analyzed in a general equilibrium model where firms with different productivity levels share among them the cost of network services and compete in a monopolistically competitive market for a differentiated good. The paper reveals that the more efficient country in the production of the differentiated good is not always the net exporter of the good. The less efficient country also has the chance to expand the industry and then to become the net exporter in this intra‐industry trade due to the combination of the efficiency effect induced by firm heterogeneity and the cost‐sharing effect by the existence of the network service industry.     

高管团队异质性对技术创业企业绩效的影响——基于扎根理论的研究

为解释高管团队异质性对技术创业企业绩效的作用机理,基于高阶理论,采用多案例扎根分析方法构建了高管团队异质性对技术创业企业绩效影响的概念模型;基于183家创业板上市公司数据,采用结构方程模型进行了实证检验。研究结果表明：高管团队年龄异质性和任期异质性对技术创业企业绩效有显著正向影响;职能经验异质性和教育水平异质性对技术创业企业绩效有显著负向影响;商业模式价值创造在高管团队年龄、任期、职能经验和教育水平异质性对技术创业企业绩效的影响中均起到部分中介作用。     

股权性质、环境不确定性与技术资本配置效率

技术转化为资本，资本创造价值已经成为共识，技术资本在不同公司创造价值的作用程度不同，根源是技术资本配置效率问题。选取沪深两市2008-2013年间制造业上市公司为样本，检验了基于不同股权性质的公司环境不确定性对企业技术资本配置效率和价值的影响，研究结果表明：①企业环境不确定性程度越高，技术资本配置效率越低，并且技术资本配置偏离度在国有公司中表现为配置过度，在非国有公司表现为配置不足；②在股权性质为国有的公司中，由环境不确定性引发的技术资本配置偏离将降低企业价值，在非国有控股公司中，由环境不确定性导致的技术资本配置偏离将增加企业价值。     

Firm heterogeneity in TFP,sectoral innovation and location. Evidence from Italy

Sectoral and territorial specificities affect a firm’s capabilities of being productive. While there is a wide consensus on this, a quantitative measure of these effects has been lacking. To this end, we combine a data-set of Italian firms with some meso regional and sectoral variables and apply a cross-classified model that allows for a clear distinction between firm, region-specific and sector-specific effects. After observing a marked TFP heterogeneity across firms, the paper addresses the issue of understanding how much differences in firms’ productivity depend on regional localisation and sector specificities. Results refer to 2004–2006 and have three aspects. First, they confirm that the main source of firm variety is mostly due to differences revealed at individual level. Secondly, we find that the sector is more important than location in explaining firms’ TFP. Lastly, the results show that firm TFP increases when it belongs to more innovative sectors. Similarly, companies get benefits from belonging to sectors where there is a high proportion of firms using R&D public support and a high propensity to collaborate in innovative projects.     

FDI spillovers in new EU member states

Using an unbalanced panel of firm‐level data in Bulgaria, Poland and Romania, we examine the impact of foreign firms on domestic firms’ productivity. In particular, we try to answer the following research questions: (1) Are there any spillover effects of foreign direct investments (FDI), and if so, are they positive or negative? (2) Are spillover effects more likely to occur within or across sectors? (3) Are the existence, the direction and the magnitude of spillovers conditioned by sector and firm‐specific characteristics? Our findings show that FDI spillovers exist both within and across sectors. The former arise when foreign firms operate in labour‐intensive sectors, while the latter occur when foreign firms operate in high‐tech sectors. Moreover, we find that domestic firm size conditions the exploitation of FDI spillovers even after controlling for absorptive capacity. We also detect a great deal of heterogeneity across countries consistent with the technology gap hypothesis.     

IT投资对我国机械制造业上市公司技术效率的影响分析

将IT投资作为投入要素和企业特征变量,基于SFA模型和DEA-Tobit模型分别构造了6个模型,以2004—2008年我国机械、设备、仪表制造业上市公司为样本,就IT投资对我国机械制造业上市公司技术效率的影响进行了实证分析。结果表明:SFA和DEA在测算技术效率方面具有较好的一致性,"生产率悖论"仍然存在;两种视角下测得的技术效率具有显著差异,且在SFA中,作为企业特征变量的IT投资的影响大于其作为生产要素的影响,这在DEA中情况正好相反;企业规模与技术效率正相关,企业资产负债率和企业年限与技术效率负相关,股权集中度与技术效率的关系不显著。     

企业规模异质性与产业集聚：来自中国制造业的证据

基于中国制造业数据,本文检验了企业规模异质性与制造业地理集中的互动联系。研究表明企业规模因素对制造业地理集中具有显著影响。按素密集度对制造业的分类回归进一步表明,上述影响存在行业差异：劳动力与资源密集型行业的相关性不稳健,但资本技术密集型行业的结果是稳健的。这意味着资本技术密集型行业的企业规模分布具有地理集中倾向：大市场集中分布了更多大规模企业。这一结论表明制造业集聚具有规模异质性：小规模企业通过集聚经济,促进生产率提高形成制造业集聚,大规模企业则通过集中分布在大市场而形成制造业集聚。另外,从制造业集聚的驱动力量看,制造业集聚的强化效应与地区异质因素两股力量都在推动制造业地理集中,由此可以判断制造业集中趋势还将持续。     

Structural Change and Economic Growth in China

This study develops a new analytical framework to account for sources of rapid economic growth in China. The traditional Solow approach is expanded to include another source of economic growth—structural change. The empirical results show that structural change has contributed to growth significantly by reallocating resources from low‐productivity sectors to high‐productivity sectors. It is found that the returns to capital investment in both agricultural production and rural enterprises are much higher than those in urban sectors, indicating underinvestment in rural areas. On the other hand, labor productivity in the agricultural sector remains low, a result of the still large surpluses of labor in the sector. Therefore, further development of rural enterprises and an increase in labor flow among sectors and across regions are key to improvements in overall economic efficiency.     

Rice market integration in the Mekong River Delta1

In the last decades Vietnam has become a major supplier in the world's rice market. This position is the result of the policy reforms that have been implemented in the agricultural sector. This paper assesses the impact of the liberalization policies and focuses on the spatial price differences in the domestic rice market. The results show that price patterns correlate strongly in the Mekong River Delta. Even prices in other regions are integrated with price patterns in the South. Interestingly, private traders in the Mekong Delta are only indirectly responsible for the latter result. They satisfy local demand and deal with state‐owned enterprises (SOEs). In the framework of the national food security policy, the state‐owned food companies ‘subsidize’ transactions between the South and the North. Moreover, the state‐owned food companies still dominate export transactions. The latter issues constitute two major queries for policy makers involved in the liberalization of the rice market, as further policy measures should not jeopardize the interests of domestic rice consumers.     

Public Monopoly,Mixed Oligopoly and Productive Efficiency

In general, the introduction of competition into the public sector seems to lead to higher cost‐efficiency in service production. However, there are examples of substantial cost increases in some areas. In this paper, using a mixed oligopoly model, we investigate the effects of deregulation on the cost‐reducing incentives of a public firm. Our results show that a firm that is a public monopoly has greater incentive to conduct cost‐reducing investment than a public firm within mixed oligopoly market.     

Big is Beautiful when Exporting

This paper starts out from the observation that the export ratios of firms (export to sales ratios) vary greatly among firms and that they are systematically higher for larger exporters. We relate the difference in export ratios to firm‐level differences in transport costs. In accordance with the data, we assume that freight rates are a function of firm‐level export volumes. We test our model using Japanese manufacturing firm‐level data. We first estimate the elasticity of the freight rate with respect to firm‐level export volumes at the sector level. When feeding these estimates back into the model, it can explain more than 50% of the variation in firm‐level export ratios.     

Benchmarking and firm heterogeneity: a latent class analysis for German electricity distribution companies

In January 2009, the German Federal Network Agency introduced incentive regulation for the electricity distribution sector based on results obtained from econometric and nonparametric benchmarking analysis. One main problem for the regulator in assigning the relative efficiency scores is unobserved firm-specific factors such as network and technological differences. Comparing the efficiency of different firms usually assumes that they operate under the same production technology, thus unobserved factors might be inappropriately understood as inefficiency. To avoid this type of misspecification in regulatory practice, estimation is carried out in two stages: in the first stage observations are classified into two categories according to the size of the network operators. Then separate analyses are conducted for each subgroup. This article shows how to disentangle the heterogeneity from inefficiency in one step, using a latent class model for stochastic frontiers. As the classification is not based on a priori sample separation criteria it delivers more robust, statistically significant, and testable results. Against this background, we analyze the level of technical efficiency of different subgroups from a sample of 200 regional and local German electricity distribution companies for a balanced panel data set (2001–2005). Testing the hypothesis if larger distributors operate under a different technology than smaller ones, we assess if a single step latent class model provides new insights to the use of benchmarking approaches within the incentive regulation schemes.     

A comparative analysis of the change in R&D efficiency: a case of R&D leaders in the technology industry

This paper measures the cumulative change in research and development (R&D) efficiency of globally leading R&D companies in the technology industry. We use Data Envelopment Analysis /Malmquist index to analyse 49 such companies. The change in R&D efficiency is analysed by decomposing the Malmquist index into ‘catch-up’ and ‘frontier shift’ indices, and by comparing cumulative indices to those at the starting period. Those cumulative indices are obtained at both a firm and an industry level. Results indicate that the overall R&D efficiency of these globally leading R&D companies declined slightly during the period 2007–2013. At a firm level, this study determines in detail how the trend of each firm in R&D activities differs from other companies.     

Labour and capital saving technical change in telecommunications

The Australian telecommunications sector is being improved and extended through substantial recent investment in intelligent technology such as digital switching, fibre optics, satellite and cellular transmission, and the Internet. These technologies are being progressively integrated with technology from the broadcasting, computer and electronics industries, providing a unified information infrastructure for information transmission and processing. Technological progress embodied in new equipment has the effect of increasing the efficiency of the factors of production. Such efficiency increases can be biased towards a particular factor. For instance, the impact of labour-augmenting technical change is a decline in the cost of labour per unit of production. When such biases are apparent the relativity between the costs of labour and capital per unit of production is changed. In the longer term, technical change can impact on the rate of employment growth and also on the rate of capital accumulation. In this study the Australian telecommunications cost structure is examined for the period 1919 to 1988. To measure labour saving and capital saving technical change a translog cost model is estimated. Multiproduct telecommunications cost studies typically employ the translog cost model (Evans and Heckman, 1984; Roöller, 1990a; 1990b; Shin and Ying, 1992; McKenzie and Small, 1997). The translog model places no a priori restrictions on substitution possibilities among the factors of production, and allows scale economies to vary with the level of output.     

Innovation and productivity in the food vs. the high-tech manufacturing sector

ABSTRACT

The food sector is considered a mature industry characterized by low research and development (R&D) intensity. Nevertheless, food companies face numerous challenges and cannot do without innovation activity if they want to keep their competitiveness. In this study, we examine the impact of innovation on labor productivity in European food companies and compare it to results for firms operating in high-tech sectors. The central motivation of our study is that the low R&D intensity observed in the food sector should be mirrored in different productivity effects of innovation when compared to the high-tech sector. We use microdata from the European Union's ‘Community Innovation Survey’ (CIS) and apply an endogeneity-robust multi-stage model that has been applied by various recent studies. Our results point out major differences between the examined subsectors. While we find strong positive effects of innovation on labor productivity for food firms, we find insignificant effects in the high-tech sector. This might suggest that the returns to innovation might be best evaluated separately by sector rather than for the manufacturing sector as a whole.     

Impact of the adoption of information and communication technologies on firm efficiency in the Tunisian manufacturing sector

This paper aims at measuring the impact of information and communication technology use on the efficiency of the Tunisian manufacturing sector at the firm level within a simple theoretical framework. We are using a firm-level panel data for the manufacturing sector in Tunisia to investigate whether adoption of ICT influences efficiency in factor use. The analysis is conducted through the use of a parametric method to measure technical efficiency. We estimate a stochastic production frontier and the relationship aims to explain technical efficiency differentials in a single stage as suggested by Battese and Coelli [Battesse, G.E, Coelli, T.J. (1995). A model for technical inefficiency in a stochastic frontier production function for panel data. Empirical Economics, 20, 325–332].The results have confirmed the presence of positive returns to ICT capital. We have found that the impact of ICT on efficiency is strong. Our results also suggest that it is important to carefully control for human capital related characteristics of employment when studying the effect of ICT. The evidence shows that achieving benefits from investment in ICT requires complementary investments and changes in human capital. This means that the combined use of ICT and human capital in a firm would enhance its efficiency beyond the direct effects of these factors taken alone.     

中国电子商务企业生存的实证分析

本文通过Logisitc回归模型，对电子商务企业生存的影响因素进行了分析。笔者认为，电子商务企业的生存是受企业自身基因构成决定的，而电子商务企业的基因构成包括了企业家才能、资金、信息资本、人力资本、社会资本和技术资本。同时，企业的基因会随着环境的变化而不断地进行着调整和整合，以适应竞争的需要。实证分析的结果证实了笔者的判断。     

DO STOCK MARKETS VALUE EFFICIENCY?

An empirical model determining the relationship between changes in firm-level productivity and changes in firm value is estimated using an unbalanced panel of 706 public limited companies observed over the period 1996–2002. We find a positive relationship between efficiency and the market value of manufacturing sector firms controlling for traditional accounting measures of performance such as earnings per share and the return on capital employed. This evidence is consistent with the stock market valuing the adoption of better management practices that lead to better resource utilisation. By contrast, we find no such evidence for service sector firms.