A Practitioner's Guide to Stochastic Frontier Analysis Using Stata provides practitioners in academia and industry with a step-by-step guide on how to conduct efficiency analysis using the stochastic frontier approach. The authors explain in detail how to estimate production, cost, and profit efficiency and introduce the basic theory of each model in an accessible way, using empirical examples that demonstrate the interpretation and application of models. This book also provides computer code, allowing users to apply the models in their own work, and incorporates the most recent stochastic frontier models developed in academic literature. Such recent developments include models of heteroscedasticity and exogenous determinants of inefficiency, scaling models, panel models with time-varying inefficiency, growth models, and panel models that separate firm effects and persistent and transient inefficiency. Immensely helpful to applied researchers, this book bridges the chasm between theory and practice, expanding the range of applications in which production frontier analysis may be implemented.

Traditional panel stochastic frontier models do not distinguish between unobserved individual heterogeneity and inefficiency. They thus force all time-invariant individual heterogeneity into the estimated inefficiency. Greene (2005) proposes a true fixed-effect stochastic frontier model which, in theory, may be biased by the incidental parameters problem. The problem usually cannot be dealt with by model transformations owing to the nonlinearity of the stochastic frontier model. In this paper, we propose a class of panel stochastic frontier models which create an exception. We show that first-difference and within-transformation can be analytically performed on this model to remove the fixed individual effects, and thus the estimator is immune to the incidental parameters problem. Consistency of the estimator is obtained by either N → ∞ or T → ∞, which is an attractive property for empirical researchers.

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Study Type – Therapy (case series) Level of Evidence 4 OBJECTIVE To determine the effectiveness of the Resonance ureteral stent and clarify the risk factors that lead to stent failure. In the present study, we review our clinical experiences using Resonance stent in treating malignant and benign ureteral obstruction. PATIENTS AND METHODS Nineteen patients with extrinsic malignant ureteral obstruction (n= 15) and benign stricture (n= 4) were retrospectively evaluated. All patients had received Resonance stent insertion through antegrade or cystoscopic retrograde approaches. The pre‐insertion and follow‐up interventions included image studies and biochemical tests. The insertion success rate, obstruction patency rate and complications were reviewed. For categorical variables, the chi‐square test and Fisher’s exact test were carried out to determine associations between variables. RESULTS The technical success rate of stent insertion was 84.6%. The mean follow‐up was 5 months (range 1–10.5 months). Five stents failed to alleviate the obstruction, and the patency rate was 77.3% (17/22). Patients who had had previous radiation therapy had a lower ureter patency rate in comparison with non‐radiation patients (50% vs 92.3% respectively, P= 0.039). The 6‐ and 9‐month patency rates were 81.0% with 11 stents and 27.0% with 3 stents, respectively. CONCLUSIONS The results of the present study demonstrated that malignant or benign ureteral obstruction could be treated safely and sufficiently with the Resonance metallic stent. Careful patient selection is critical to achieve successful results. For malignant ureteral obstruction, previous radiation therapy is a risk factor for stent failure.

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