Derivation of marginal effects of determinants of technical inefficiency

In efficiency studies using the stochastic frontier approach, the main focus is to explain inefficiency in terms of some exogenous variables and computation of marginal effects of each of these determinants. Although inefficiency is estimated by its mean conditional on the composed error term (the Jondrow et al., 1982 estimator), the marginal effects are computed from the unconditional mean of inefficiency (Wang, 2002). In this paper we derive the marginal effects based on the Jondrow et al. estimator and use the bootstrap method to compute confidence intervals of the marginal effects

Semiparametric smooth coefficient estimation of a production system

This paper addresses endogeneity of inputs in estimating a semiparametric smooth coefficient production function using a system approach. The system consists of a translog production function and the first-order conditions (FOC’s) of profit maximization. Each coefficient of the production function is an unknown function of some exogenous environmental variables. This makes the production function observation-specific so long as the environmental variables are observation-specific. The estimation of the system involves applying the functional coefficient instrumental variable method (Cai, Das, Xiong and Wu 2006) for the endogeneity of inputs in the first step, and the semiparametric smooth coefficient seemingly unrelated regression method (Henderson, Kumbhakar, Li and Parmeter 2015) in the second step. Using a Chinese food industry data set, we show that the semiparametric system approach gives most economically meaningful input elasticity estimates, compared with alternative models. We also calculate the returns to scale along with the technical and allocative inefficiency estimates

STOCHASTIC FRONTIER ANALYSIS OF SPECIALIST SURGEON CLINICS

Stochastic frontier analysis was used to estimate the technical efficiency of specialist surgeon practices based in Gauteng Province, South Africa. The analysis was conducted for both single and multiple output production functions, while efficiency was allowed to depend upon surgeon and practice characteristics.Multiple output models, due to an increase in the number of observations, can be more precisely estimated and, as there are multiple observations per surgeon, can be estimated with fixed effects. The results of the analyses suggest that efficiency averages around 50% for this sample and is convex in years of surgical experience. The benefit of multiple output analysis – improved precision – obtains, while surgeon-level fixed effects alleviate some concerns related to unobserved heterogeneity.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1813-698

Measuring persistent and transient energy efficiency in the US

The promotion of US energy efficiency policy is seen as a very important activity. Generally, the level of energy efficiency of a country or state is approximated by energy intensity, commonly calculated as the ratio of energy use to GDP. However, energy intensity is not an accurate proxy for energy efficiency given that changes in energy intensity are a function of changes in several factors including the structure of the economy, climate, efficiency in the use of resources, behaviour and technical change. The aim of this paper is to measure persistent and transient energy efficiency for the whole economy of 49 states in the US using a stochastic frontier energy demand approach. A total US energy demand frontier function is estimated using panel data for 49 states over the period 1995 to 2009 using two panel data models: the Mundlak version of the random effects model (which estimates the persistent part of the energy efficiency) and the true random effects model (which estimates the transient part of the energy efficiency). The analysis confirms that energy intensity is not a good indicator of energy efficiency, whereas, by controlling for a range of economic and other factors, the measures of energy efficiency obtained via the approach adopted here are. Moreover, the estimates show that although for some states energy intensity might give a reasonable indication of a state’s relative energy efficiency, this is not the case for all states.ISSN:1570-646XISSN:1570-647

Operational Research in Education

Operational Research (OR) techniques have been applied, from the early stages of the discipline, to a wide variety of issues in education. At the government level, these include questions of what resources should be allocated to education as a whole and how these should be divided amongst the individual sectors of education and the institutions within the sectors. Another pertinent issue concerns the efficient operation of institutions, how to measure it, and whether resource allocation can be used to incentivise efficiency savings. Local governments, as well as being concerned with issues of resource allocation, may also need to make decisions regarding, for example, the creation and location of new institutions or closure of existing ones, as well as the day-to-day logistics of getting pupils to schools. Issues of concern for managers within schools and colleges include allocating the budgets, scheduling lessons and the assignment of students to courses. This survey provides an overview of the diverse problems faced by government, managers and consumers of education, and the OR techniques which have typically been applied in an effort to improve operations and provide solutions

Measuring productivity and efficiency: a Kalman filter approach

In the Kalman filter setting, one can model the inefficiency term of the standard stochastic frontier composed error as an unobserved state. In this study a panel data version of the local level model is used for estimating time-varying efficiencies of firms. We apply the Kalman filter to estimate average efficiencies of U.S. airlines and find that the technical efficiency of these carriers did not improve during the period 1999-2009. During this period the industry incurred substantial losses, and the efficiency gains from reorganized networks, code-sharing arrangements, and other best business practices apparently had already been realized