Sequential forward selection (SFS) is one of the most widely used feature selection procedures. It starts with an empty set and adds one feature at each step. The estimate of the quality of the candidate subsets usually depends on the training/testing split of the data. Therefore different sequences of features may be returned from repeated runs of SFS. A substantial discrepancy between such se...

Structural change has been conjectured to lead to an upward bias in the estimated forward expectations coefficient in New-Keynesian Phillips curves. We present a simple New-Keynesian model that enables us to assess this proposition. In particular, we investigate the issue of upward bias in the estimated coefficients of the expectations variable in the New-Keynesian Phillips curve based on a mod...

Background: We developed a new near-subject approach, using flowing afterglow–mass spectrometry (FA-MS) and deuterium dilution, which enables the immediate measurement of total body water (TBW) from single exhalations. Objectives: The objectives were to show the efficacy of the new FA-MS method in measuring TBW in healthy subjects and to compare these measurements with values derived from multi...

BACKGROUND We developed a new near-subject approach, using flowing afterglow-mass spectrometry (FA-MS) and deuterium dilution, which enables the immediate measurement of total body water (TBW) from single exhalations. OBJECTIVES The objectives were to show the efficacy of the new FA-MS method in measuring TBW in healthy subjects and to compare these measurements with values derived from multi...

Epidemiologists typically seek to answer causal questions using statistical data: we observe a statistical association between poverty and early mortality and seek to determine whether poverty causes early death. An essential component of epidemiologic training is therefore learning what statistical relations imply, or do not imply, about causal relations. This is why the cliché “correlation do...

The aim of this study was to investigate the validity of the Tanita TBF 300A leg-to-leg bioimpedance analyzer for estimating fat-free mass (FFM) in Bangladeshi children aged 4-10 years and to develop novel prediction equations for use in this population, using deuterium dilution as the reference method. Two hundred Bangladeshi children were enrolled. The isotope dilution technique with deuteriu...

Investigation of peer effects on achievement with sample survey data on schools may mean that only a random sample of peers is observed for each individual. This generates classical measurement error in peer variables, resulting in the estimated peer group effects in a regression model being biased towards zero under OLS model fitting. We investigate the problem using survey data for England fr...

The manuscript discusses how to incorporate random effects for quantile regression models clustered data with focus on settings many but small clusters. paper has three contributions: (i) documenting that existing methods may lead severely biased estimators fixed parameters; (ii) proposing a new two-step estimation methodology where predictions of the are first computed {by pseudo likelihood ap...