The randomized response technique (Warner, 1965) is a data collection procedure that allows researchers to collect sensitive information while guaranteeing privacy to respondents. For example, if one question from a pair of questions that have the same response options is selected randomly and in private, the question answered by a given individual will not be known to the researcher. However, ...

Nieto and Coresh (1) are reviewing alternative methods for presenting adjusted survival curves. The proposed new method is a special case of the Ederer II method currently used at cancer registries worldwide. In addition, there are other frequently used methods for adjusting for deaths and censorings that are not mentioned. It is important to state the context in which any adjusted survival cur...

BACKGROUND The number of clusters in a cluster randomized trial is often low. It is therefore likely random assignment of clusters to treatment conditions results in covariate imbalance. There are no studies that quantify the consequences of covariate imbalance in cluster randomized trials on parameter and standard error bias and on power to detect treatment effects. METHODS The consequences ...

A new approach for constructing tests for association between a random right censored life time variable and a covariate is proposed. The basic idea is to first arrange the observations in increasing order of the covariate and then base the test on a certain point process defined by the observation times. Tests constructed by this approach are robust against outliers in the covariate values or ...

Reference growth curves estimate the distribution of a measurement as it changes according to some covariate, often age. We present a new methodology to estimate growth curves based on mixture models and splines. We model the distribution of the measurement with a mixture of normal distributions with an unknown number of components, and model dependence on the covariate through the weights, usi...

A major assumption of the Cox proportional hazards model is that the effect of a given covariate does not change over time. If this assumption is violated, the simple Cox model is invalid, and more sophisticated analyses are required. This paper describes eight graphical methods for detecting violations of the proportional hazards assumption and demonstrates each on three published datasets wit...

Dan Zhang Leads School of Business, University of Colorado at Boulder, Boulder, CO 80309, USA [email protected] Inventory-based dynamic pricing has become a common operations strategy in practice and has received considerable attention from the research community. From an implementation perspective, it is desirable to design a simple policy like a base stock list price (BSLP) policy. The e...

Oracally Efficient Two-Step Estimation of Generalized Additive Model Rong Liu a b , Lijian Yang a c & Wolfgang K. Härdle d a Center for Advanced Statistics and Econometrics Research , Soochow University , China b Department of Mathematics and Statistics , University of Toledo , Toledo , OH , 43606 c Department of Statistics and Probability , Michigan State University , East Lansing , MI , 48824...