Alexander D. Stead

University of Leeds · Institute for Transport Studies (ITS)

When analysing the efficiency of decision-making units, the robustness of efficiency scores to changes in the data is desirable, especially in the context of managerial or regulatory benchmarking. However, the robustness of maximum likelihood estimation of stochastic frontier models remains underexplored. We examine the behaviour of the influence f...

High passenger and freight transport costs are a barrier to economic growth and social mobility, particularly in Low Income Countries (LICs). This paper considers the current state of knowledge regarding the barriers to achieving lower generalised transport costs. It considers both the road and railway modes across passenger and freight transport....

The liberalisation of passenger rail markets across Europe in recent years has focussed not only on competition for the market, but increasingly on competition in the market in the form of entry by open access operators. The possible benefits of such competition in terms of innovation and demand growth must, however, be balanced against concerns re...

Multiple Imputation (MI) methods have been widely applied in economic applications as a robust statistical way to incorporate data where some observations have missing values for some variables. However in Stochastic Frontier Analysis (SFA), application of these techniques has been sparse and the case for such models has not received attention in t...

The presence of outliers in the data has implications for stochastic frontier analysis, and indeed any performance analysis methodology, because they may lead to imprecise parameter estimates and, crucially, lead to an exaggerated spread of efficiency predictions. In this paper we replace the normal distribution for the noise term in the standard s...

This chapter is a survey of developments in stochastic frontier modelling. The literature on stochastic frontiers has grown substantially in the 40 years since the seminal work by Aigner et al. [J. Econom., 18(2), pp. 21-37, (1977)]. There exist many surveys of this literature that cover a broad range of contribution pathways in the field. In this...

In Stochastic Frontier Analysis the presence of outliers in the data, which can often be safely ignored in other forms of linear modelling, has potentially serious consequences in that it may lead to implausibly large variation in efficiency predictions when based on the conditional mean. This motivates the development of alternative stochastic fro...

In Stochastic Frontier Analysis the presence of outliers in the data, which can often be safely ignored in other forms of linear modelling, has potentially serious consequences in that it may lead to implausibly large variation in efficiency predictions when based on the conditional mean. This motivates the development of alternative stochastic fro...