Estimation of technical inefficiency effects using panel data and doubly heteroscedastic stochastic production frontiers

In previous studies, measures of technical inefficiency effects derived from stochastic production frontiers have been estimated from residuals which are sensitive to specification errors. This study corrects for this inaccuracy by extending the doubly heteroscedastic stochastic cost frontier suggested by Hadri (1999) to the model for technical inefficiency effects. This model is a stochastic frontier production function for panel data as proposed by Battese and Coelli (1995). The study uses, for illustration of the techniques, data on 101 mainly cereal farms in England. We find that the correction for heteroscedasticity is supported by the data. Both point estimates and confidence intervals for technical efficiencies are provided. The confidence intervals are constructed by extending the “Battese-Coelli” method reported by Horrace and Schmidt (1996) by allowing the technical inefficiency to be time varying and the disturbance terms to be heteroscedastic. The confidence intervals reveal the precision of technical efficiency estimates and show the deficiencies of making inferences based exclusively on point estimates. First version received: March 2000/Final version received: Oct. 2001 RID="*" ID="*"  The authors are grateful to the Economic and Social Research Council for access to their Data Archive which has provided the data for this research. We are indebted to Badi Baltagi and two anonymous referees for their helpful comments and suggestions. The usual caveat applies.     

How R&;D investments influence TFP growth: Evidence from China’s large and medium-sized industrial enterprises

This paper investigates the potential channels through which R&D may influence TFP growth using industry-level panel data of China’s large and medium-sized industrial enterprises over the period of 2000–2007. Comparing with existing literature, we provide a closer look of the relationship between R&D and TFP growth by decomposing TFP growth into efficiency change and technical change components using Malmquist productivity index and distinguishing between upstream R&D spillovers and downstream R&D spillovers. We find TFP grow slightly during 2000–2007, and R&D investment indeed serves as an engine of productivity growth just as endogenous growth theories argued, which is largely because R&D accelerates technical progress even it also results in enlarging technical inefficiency. However, we find a robust negative effect of downstream R&D spillovers on TFP growth, the effects of upstream is positive but not statistically significant. In addition, we do not find the positive effects of human capital on TFP as endogenous growth theories indicated, but find human capital severs as “assimilation device” for R&D spillovers both in promoting TFP growth and increasing technical efficiency even the effects on technical progress is adverse.     

On the choice of functional form in stochastic frontier modeling

This paper examines the effect of functional form specification on the estimation of technical efficiency using a panel data set of 125 olive-growing farms in Greece for the period 1987–93. The generalized quadratic Box-Cox transformation is used to test the relative performance of alternative, widely used, functional forms and to examine the effect of prior choice on final efficiency estimates. Other than the functional specifications nested within the Box-Cox transformation, the comparative analysis includes the minflex Laurent translog and generalized Leontief that possess desirable approximation properties. The results indicate that technical efficiency measures are very sensitive to the choice of functional specification. Perhaps most importantly, the choice of functional form affects the identification of the factors affecting individual performance – the sources of technical inefficiency. The analysis also shows that while specification searches do narrow down the set of feasible alternatives, the identification of the most appropriate functional specification might not always be (statistically) feasible. First version received: November 1999/Final version received: July 2001 RID="*" ID="*"  The authors wish to thank Almas Heshmati, Robert Romain, and an anonymous referee for insightful comments and suggestions. Special thanks go to the associate editor who handled the paper, and whose careful reading and suggestions have improved the paper substantially. The second author wishes to acknowledge the financial support from “President SSHRC” from the University of Saskatchewan. The usual caveats with respect to opinions expressed in the paper apply. Senior authorship is shared. This is University of Nebraska-Lincoln Agricultural Research Division Article No. 13270.     

Regulation and efficiency in transition: the case of Romanian banks

Using disaggregated panel data for the period 1996–2002, this paper estimates the cost efficiency of Romanian banks and relates it to regulation implemented by the National Bank of Romania. We estimate efficiency using a model that combines the frameworks of both stochastic frontier analysis and shadow cost functions. Our results indicate that, for all types of banks, the cost of technical inefficiency decreases in the years following tightening of regulation. A significant part of this decrease can be attributed to the policy change. Overall, the short-run increase in cost due to additional regulation exceeds the benefits from reduced technical inefficiency. However, our model does not account for other benefits, besides changes in X-inefficiency, such as stability of the banking system, which may be significant.      

Specification and estimation of stochastic multiple-output production and technical inefficiency

This paper presents a primal-based approach for specification and estimation of multiple-output production frontiers that allows simultaneous identification and estimation of determinants of technical inefficiency. The proposed model extends the technical efficiency effects model by Battese and Coelli (1995) to general multiple-output technologies. An empirical application using Swedish health care panel data from the years 1989–1994 is included. The key issue is to test for the effects on technical efficiency of an organizational reform implemented with the primary purpose to increase efficiency. The results reveal no significant effect on technical efficiency of the reform, but evidence of overall decreased technical efficiency and technical progress in the provision of health care over the studied time period are found.     

Efficiency and Equity in School Funding: A Case Study for Kansas

This study measures cost inefficiency of Kansas public school districts and applied both mathematical programming and stochastic frontier approach. The empirical study uses two-stage data envelopment analysis model and the cost inefficiency effects model proposed by Battese and Coelli (Empirical Economics 24:325–332, 1995) and applied to a panel data. The results found mean inefficiencies from these two models are very close. The results indicate that Kansas school districts, on average, exhibit cost inefficiency in their operations, however, there is a tendency for inefficiencies to decline over time. The study does not find any strong evidence for lower efficiency due to lower expenditure per-pupil. Instead, we found inconclusive evidences where lower efficiency for certain school districts could be assigned to unfavorable environmental cost conditions.

Regulatory and environmental effects on public transit efficiency: a mixed DEA-SFA approach

This paper assesses the impact of regulatory and environmental factors and statistical noise on the efficiency of public transit systems within a DEA-based framework. Using a panel of Italian companies, we implement a DEA-SFA mixed approach based on [H.O. Fried et al. (2002) Journal of Productivity Analysis, 17(1–2), 157–174] to decompose DEA inefficiency measures into three components: exogenous effects, managerial inefficiency and stochastic events. Besides providing evidence on the determinants of input-specific efficiency differentials across companies, the results point out that managerial skills play a minor role, and emphasize the relevance of regulatory policies aimed at replacing cost-plus subsidization with high-powered incentive contracts as well as improving environmental conditions of public transit networks.      

Scale and efficiency measurement using a semiparametric stochastic frontier model: evidence from the U.S. commercial banks

In this paper, we use the local maximum likelihood (LML) method proposed by Kumbhakar et al. (J Econom, 2007) to estimate stochastic cost frontier models for a sample of 3,691 U.S. commercial banks. This method relaxes several deficiencies in the econometric estimation of frontier functions. In particular, we relax the assumption that all banks share the same production technology and provide bank-specific measures of returns to scale and cost inefficiency. The LML method is applied to estimate the cost frontiers in which a truncated normal distribution is used to model technical inefficiency. This formulation allows the cost frontier, inefficiency effects and heteroskedasticity in both noise and inefficiency components to be quite flexible.      

Technical Efficiency in Australian Textile and Clothing Firms: Evidence From the Business Longitudinal Survey

This paper estimates technical efficiency of Australian textile and clothing firms based on the data obtained from the Business Longitudinal Survey (BLS) conducted by the Australian Bureau of Statistics (ABS). Using a Cobb Douglas stochastic production frontier the paper examines firm level technical efficiency in the time varying inefficiency effect model with technical inefficiency effects assumed as an independently distributed truncated normal variable. Estimates of the production frontier revealed significant but small elasticities of labour and capital for textile and clothing firms, respectively, and a negative (but insignificant) Hicks neutral technical change for both. Estimated coefficients of the explanatory variables for inefficiency effects indicated that technical efficiency varied significantly according to firms' age, size, capital intensity, proportion of non-production to total workers and type of legal status. Predicted firm specific efficiency varied from 16 per cent to 95 per cent and mean efficiency ranged between 30 to 70 per cent. In view of these results policies have been suggested to improve technical efficiency of the firms as well as productivity growth of the sub sectors.     

Measurement of technical and allocative efficiencies using a CES cost frontier: a benchmarking study of Japanese transmission-distribution electricity

This paper estimates the technical and allocative inefficiencies of the transmission-distribution sector of Japanese electric utilities using a panel data during the 1981–1998 period. A stochastic production frontier of the CES form is jointly estimated with input demand equations. Taking advantage of the self-duality, we retrieve the cost frontier by which the impacts of technical and allocative inefficiencies on costs and input demands are measured. The estimated elasticity of substitution is significantly different from unity in favor of the CES specification over the Cobb–Douglas. The results show that observed costs are 9 to 48% higher than the efficient level; technical inefficiency raises costs by 1 to 28%, while allocative inefficiency does so by 8 to 30%. Although their impacts on costs are similar, technical inefficiency more fluctuates so the differences in the performance of utilities are mainly due to technical inefficiency. We also find a substantial over-utilization of capital for all utilities.

FDI, domestic capital and economic growth: Evidence from panel data at China’s provincial level

Based on panel data at the provincial level in China, this paper found that direct effects foreign direct investment (FDI) had on economic growth were of insignificance. However, through improving technical efficiency and “crowding” in domestic investment, FDI produced positive effects on China’s economy. The state sector still played a major part in the total fixed investment, therefore, direct effects on growth were significant. Although private sector was increasingly important for the whole economy, it had no direct influences on economic growth. Meanwhile, neither the state sector nor private sector made contribution to the improvement on technical efficiency. __________ Translated from Shijie Jingji Wenhui 世界经济文汇 (World Economic Papers), 2006, (4): 27–43     

How technically efficient are Singapore's manufacturing industries?

This study attempts to understand the technical efficiency performance (i.e. how well resources and given technology are being used) in 28 manufacturing industries in Singapore from 1975–1994, using an improved version of the stochastic frontier model. In addition, an analytical model is used to investigate the causes of technical inefficiency in these industries to help policy formulation. The efficiency performance of foreign and local-dominated industries is also closely examined.     

Trade liberalization and technical efficiency in the Indonesian chemicals industry

This article examines the impact of trade reform on technical efficiency on the Indonesian chemicals industry using firm-level panel data. The effects of trade reform on technical efficiency are analysed using a stochastic frontier approach. Two variables represent trade reform in this model: effective rate of protection (ERP) and import ratio (IMP). The findings of the present study suggest that both trade reform variables have significant effects on technical efficiency. The coefficient of ERP has a positive sign and is statistically significant, which means that an increase in ERP increases the inefficiency (or decreases the technical efficiency) of firms in the chemicals industry. The coefficient of IMP is negative and statistically significant, which represents the negative impact of IMP on technical inefficiency (or positive on technical efficiency). Thus, trade reform, a reduction in ERP or an increase in IMP, has an unambiguously positive effect on technical efficiency in the Indonesian chemicals industry.     

Human capital effects on technical inefficiency: a stochastic frontier analysis across industries of the Greek economy

In this paper we examine the impact of human capital on technical inefficiency. A stochastic production frontier is simultaneously estimated with a technical inefficiency model using data from one-digit industries of the Greek economy, for the period 2000–2005. The results indicate a significantly negative impact of human capital on technical inefficiency, which is comparatively lower in magnitude for the sector of public services. The most efficient industries of the Greek economy are those of Education, Financial intermediation and Real estate, renting & business activities. The highest contribution of human capital on technical efficiency is observed in the industries of Health, Education and Real estate, renting & business activities.     

Sources of investment inefficiency: The case of fixed-asset investment in China

This study attempts to measure the inefficiency associated with aggregate investment in a transitional economy. The inefficiency is decomposed into allocative and technical inefficiency based on standard production theory. Allocative inefficiency is measured by the deviation of actual investment from the theoretically desired investment demand. Institutional factors are then identified as part of the driving force of the deviation. The resulting model is applied to Chinese provincial panel data. The main findings are: Chinese investment demand is strongly receptive to expansionary fiscal policies and inter-provincial network effects; the tendency of over-investment remains, even with signs of increasing allocative efficiency and improving technical efficiency.     

Openness and the Efficiency of FDI: A Panel Stochastic Production Frontier Study

This paper uses a stochastic translog production frontier to estimate technical inefficiency indices whose conditional mean is specified as a function of FDI and its interaction with openness of the economy. The model is estimated using an annual panel of 46 countries for the years, 1981–2001. The results suggest that increased FDI increases potential output in both developed and developing countries with the effect being more profound in the former. It is also found that increased FDI reduces technical inefficiencies the more open is the economy but that this effect holds only for developed economies. Thus qualified support is found for the “Bhagwati hypothesis” as the results reveal that the efficiency–enhancing effect of FDI depends not only on openness but also on the degree of development of the host country.

The Zilcha criteria for dynamic inefficiency reconsidered

We reconsider necessary and sufficient conditions for dynamic inefficiency given in Zilcha (J Econ Theory 52:364–379, 1990, J Econ Theory 55:1–16, 1991) and a critique by Rangazas and Russell (2005). First, we show that the characterization given in Zilcha (1990) for nonstationary economies is correct and correct Zilcha’s proof. Second, using this insight, we complement Rangazas and Russell’s (Econ Theory 26:701–716, 2005) discussion of the counterexamples to Zilcha (J Econ Theory 55:1–16, 1991). Third, we discuss consequences of our results for applied tests of (in-)efficiency based on the Zilcha criteria. We would like to thank Itzhak Zilcha, and in particular Peter Rangazas and Steve Russell for detailed and very helpful comments.     

A model for technical inefficiency effects in a stochastic frontier production function for panel data

A stochastic frontier production function is defined for panel data on firms, in which the non-negative technical inefficiency effects are assumed to be a function of firm-specific variables and time. The inefficiency effects are assumed to be independently distributed as truncations of normal distributions with constant variance, but with means which are a linear function of observable variables. This panel data model is an extension of recently proposed models for inefficiency effects in stochastic frontiers for cross-sectional data. An empirical application of the model is obtained using up to ten years of data on paddy farmers from an Indian village. The null hypotheses, that the inefficiency effects are not stochastic or do not depend on the farmer-specific variables and time of observation, are rejected for these data.     

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.     

中国地区工业生产绩效:结构差异、制度冲击及动态表现

This paper is dedicated to probing into the dynamic performances of industrial productivity across regions of transitional China, using the panel data of provincial level. Based on the approach by Kumbhakar (2000), TFP (total factor productivity) growth is decomposed into four components. The main results are as follows. First, since 1988, the industrial TFP growth has been commonly accelerated across regions, with a rising technical change rate as the principal impetus. Second, meanwhile, technical efficiency and factors’ allocative efficiency are deteriorated with scale efficiency switching from being retrogressive to being progressive. Third, although the SOE (state-owned enterprise) reform in the late 1990s has constituted a common shock to the industrial productivity, the eastern area with relatively few SOEs suffers the least from this policy enforcement. Fourth, by exploring the sources of productivity differences, we further confirm that the institutional shock launched by SOE reform in the late 1990s is crucial for the enhancement of scale effects as well as the temporarily rapid decline of factors’ allocative efficiency; in addition, the educational level of the labor-force and the share of non-SOEs in the industrial output contribute positively to the acceleration of technical change and the improvement of allocative efficiency. The economic transition, accompanied by gradual institutional reforms, is reshaping the map of regional industrialization through various channels. Translated from Jingji Yanjiu 经济研究 (Economic Research Journal), 2006, (11): 48–59