Simulated Likelihood Estimation of the Normal-Gamma Stochastic Frontier Function

The normal-gamma stochastic frontier model was proposed in Greene (1990) and Beckers and Hammond (1987) as an extension of the normal-exponential proposed in the original derivations of the stochastic frontier by Aigner, Lovell and Schmidt (1977). The normal-gamma model has the virtue of providing a richer and more flexible parameterization of the inefficiency distribution in the stochastic frontier model than either of the canonical forms, normal-half normal and normal-exponential. However, several attempts to operationalize the normal-gamma model have met with very limited success, as the log likelihood is possesed of a significant degree of complexity. This note will propose an alternative approach to estimation of this model based on the method of maximum simulated likelihood estimation as opposed to the received attempts which have approached the problem by direct maximization.     

The effect of public sector employment on the earnings of white and African American males: A sample selectivity approach

This research note uses a sample selection model to measure the earnings premium (or penalty) to public sector employment. A model correcting for both labor force participation and sectoral choice is estimated for both white and African American males. Results indicate that African American males are no better off in the public than in the private sector. Moreover, white males employed in the public sector earn significantly less than their private sector counterparts.     

Recovering costs through price and service differentiation: Accounting for exogenous information on attribute processing strategies in airline choice

The entry of low cost airlines has thrown out a challenge to all airlines to find ways of attracting passengers, through a mix of fare discounting, greater frequency, improved flight times and no-frill's levels of on-board service. These competitive strategies have an impact on cost recovery. As airlines seek business in an increasingly heterogeneous passenger market, a greater understanding of what matters to potential passengers in choosing an airline grows in importance. Traditional studies of passenger airline choice assume that all attributes matter, but some to a lesser extent. What happens to the empirical evidence on willingness to pay when specific attributes are totally ignored by particular passengers? In this paper, we examine the impact of individual-specific attribute processing strategies (APS) on the inclusion/exclusion of attributes on the parameter estimates and behavioural outputs of models of airline service and fare level choice. Modelling practice assumes that whilst respondents may exhibit preference heterogeneity, they employ a homogenous APS with regards to how they process the presence/absence of attributes of stated choice (SC) experiments. We demonstrate how information collected exogenous of the SC experiment on whether respondents either ignored or considered each attribute of the SC task may be used in the estimation process, and how such information may be used to provide outputs that are attribute processing strategies segment specific.     

Female consumers: Decision-making in brand-driven retail

This article is a theory-building exploratory study conducted to investigate how female shoppers make meaning in a branded-retail store shopping experience. This study extends research on retail consumers' decision-making and the retail shopping experience using hermeneutic phenomenology. The authors conducted in-depth interviews with respondents, who were self-identified customers of a leading intimate apparel retailer. The results suggest that consumers' retail shopping decision-making incorporates a complex set of interactive components that are brand-driven and simultaneously affect and are affected by the interaction of in-store shopping and retail setting. The findings show a rich understanding of the consumer decision-making process is achievable by including the actual in-store experience, consumers' prior contextual experiences and expectations regarding retail visits.     

EFT — emerging issues in internationally related payments

Marjorie Greene of the Inter-Bank Research Organization comments on ‘Regulatory inhibitions on the development of electronic message systems in the USA’ by Philip S. Nyborg, published in the December 1978 issue of Telecommunications Policy.     

The Role of Private Equity in Life Sciences

In a roundtable published in this journal a year ago, there was a clear consensus that the R&D function in big pharma was inefficient and in need of major restructuring, possibly through increased investments by venture capital and private equity firms. In this discussion, an accomplished group of industry practitioners begins by looking at the prospects for both venture capital and private equity to play meaningful roles in financing early- and mid-stage drug development. In so doing, they explore questions like the following:

• • Are there ways for big pharma and biotech to reduce “science risk” and make R&D funding more profitable and attractive to venture capital and private equity—and perhaps even hedge funds?
• • What roles do you see for specialty PE firms like Symphony Capital and Paul Capital, which are now bundling mid-stage development assets and securitizing royalties?

Then the panelists turn to the broader life sciences industry and consider the outlook for leveraged private equity transactions involving marketed products, late-stage development, and services. Here they consider issues like the following:

• • Will PE be attracted to less-R&D-intensive activities like medtech and generics?
• • Have the recent consolidation through mergers and reorganization of big pharma into decentralized business units created opportunities for carve-outs of certain businesses?

For big pharma and life sciences companies in general, the answers to such questions point to greater specialization and focus achieved partly through strategic alliances with venture capital, private equity, and even hedge funds, and involving marketed products and services as well as early-stage drug development.     

Revisiting the influence of institutional forces on the written business plan: a replication study

The present paper re-analyzes and extends a study on institutional forces and the written business plan (Honig and Karlsson in J Manag 30(1):29–48, 2004). We attempt to examine to what extent critical decision making is evident in model and variable choice, and whether the implications provided by systematic replication efforts may serve to provide additional and perhaps unrecognized theoretical and/or empirical observations. We find that the key result—formal business planning does not affect performance, does not hold. In fact, we find evidence that formal business planning affects survival but not profitability. The re-analysis also reveals, that institutional antecedents to formal planning appear to be fragile and prone to researcher biases due to different coding and assumptions. Our study underscores the consequences of access to original data and coding material, and to rely upon current methodological explanations for subsequent analyses.     

The gender representation gap: implications for workplace union effectiveness

This article investigates how the gender of workplace representatives has implications for three dimensions of union effectiveness: (i) responsiveness to members, (ii) opportunity to influence management and (iii) ability to bring about change. Utilising original analysis of the 2011 Workplace Employment Relations Study, we examine three core elements of workplace employment relations processes that cut across the three dimensions: (i) workplace representation processes and employer support for union activity; (ii) substantive areas of representative involvement and (iii) quality of relations between union representatives and management, and between union representatives and employees. Our analysis highlights significant gender differences embedded in all three processes. The conclusion considers the broader implications of these findings for the gender equality project of British trade unions, beyond the objective of merely seeking to increase the numbers of women representatives.     

Robust stochastic frontier analysis: a Student’s t-half normal model with application to highway maintenance costs in England

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 stochastic frontier model with a Student’s t distribution, which generalises the normal distribution by adding a shape parameter governing the degree of kurtosis. This has the advantages of introducing flexibility in the heaviness of the tails, which can be determined by the data, as well as containing the normal distribution as a limiting case, and we outline how to test against the standard model. Monte Carlo simulation results for the maximum simulated likelihood estimator confirm that the model recovers appropriate frontier and distributional parameter estimates under various values of the true shape parameter. The simulation results also indicate the influence of a phenomenon we term ‘wrong kurtosis’ in the case of small samples, which is analogous to the issue of ‘wrong skewness’ previously identified in the literature. We apply a Student’s t-half normal cost frontier to data for highways authorities in England, and this formulation is found to be preferred by statistical testing to the comparator normal-half normal cost frontier model. The model yields a significantly narrower range of efficiency predictions, which are non-monotonic at the tails of the residual distribution.