Estimation Methods for Duration Models

This paper is a selected overview of econometric methods for duration models and will appear in the forthcoming book The Economics of Search by the authors. The focus of the paper is on martingale methods for continuous time data and general methods for the analysis of discretetime data including multi-spell models and general life-history models.

A Regulatory Framework for Strengthening Defined Benefit Pensions

Recent financial market and plan termination experiences have exposed the shortcomings of existing funding, disclosure, and premium rules governing private single-employer defined benefit pension plans in the United States. These rules were designed to provide predictability for plan sponsors and administrators, by insulating pension plans from the realities of economic and financial market fluctuations. Unfortunately current practice often overlooks key financial principles that arguably should inform a responsible set of pension rules and the insurance system backing the plans. We outline the key characteristics of pension plans needed to beneficially guide rule-making and offer examples drawn from proposed funding and premium rule

Construction of the GAMCIT gamma-ray burst detector (G-056)

The GAMCIT (Gamma-ray Astrophysics Mission, California Institute of Technology) payload is a Get-Away-Special payload designed to search for high-energy gamma-ray bursts and any associated optical transients. This paper presents details on the development and construction of the GAMCIT payload. In addition, this paper will reflect upon the unique challenges involved in bringing the payload close to completion, as the project has been designed, constructed, and managed entirely by undergraduate members of the Caltech SEDS (Students for the Exploration and Development of Space). Our experience will definitely be valuable to other student groups interested in undertaking a challenge such as a Get-Away-Special payload

B-type natriuretic peptide predicts deterioration in functional capacity following lung resection

OBJECTIVES Following lung resection, there is a decrease in the functional capacity and quality of life, which is not fully explained by changes in pulmonary function. Previous work demonstrates that B-type natriuretic peptide (BNP) is associated with short- and long-term complications following lung resection, leading to the suggestion that cardiac dysfunction may contribute to functional deterioration. Our aim was to investigate any relationship between BNP and subjective and objective indices of functional deterioration following lung resection surgery. METHODS Twenty-seven patients undergoing lung resection had serum BNP measured preoperatively, on postoperative day (POD)1 and POD2, and at 2 months postoperatively. The functional deterioration was assessed using 6-min walk tests and the Medical Research Council dyspnoea scale. ‘Deterioration in functional capacity’ was defined as either an increase in the Medical Research Council dyspnoea score or a significant decrease in the 6-min walk test distance. RESULTS BNP increased over time (P < 0.01) and was significantly elevated on POD1 and POD2 (P < 0.02 for both). Seventeen patients demonstrated functional deterioration 2 months postoperatively. At all perioperative time points, BNP was significantly higher in patients showing deterioration (P < 0.05 for all). Preoperative BNP was predictive of functional deterioration at 2 months with an area under the receiver-operating characteristic curve of 0.82 (P = 0.01, 95% confidence interval 0.65–0.99). CONCLUSIONS This study has demonstrated, using subjective and objective measures, that preoperative BNP is a predictor of functional deterioration following lung resection. BNP may have a role in preoperative risk stratification in this population, allowing therapy in future to be targeted towards high-risk patients with the aim of preventing postoperative cardiac dysfunction. Clinical trial registration number: NCT01892800