A common objective in longitudinal studies is to characterize the relationship between a longitudinal response process and a time-to-event. Considerable recent interest has focused on so-called joint models, where models for the event time distribution and longitudinal data are taken to depend on a common set of latent random effects. In the literature, precise statement of the underlying assum...

This note shows three cases in which a considerable loss of efficiency can result from assuming a parametric distribution for a random effect that is substantially different from the true distribution. For two simple models for binary response data, we studied the effects of assuming normality or of using a nonparametric fitting procedure for random effects, when the true distribution is potent...

In this paper, we study a method to construct a multivariate counting process with positive dependencies between the event occurrences. Conditional on a random effect with a positive stable distribution, the univariate counting processes are independent non-homogeneous Poisson processes with a power intensity function. The applicability of the model is illustrated in three examples: a horse rac...

In the present study, effects of NaCl concentrations (0, 20, 40 and 80 mM) were investigated in Ceratophyllum demersum. Macronutrients N, P and K and micronutrients Zn and Cu were significantly decreased by NaCl salinity. In general, however, Fe and Mn accumulation showed to increase. As a results, NaCl toxicity disturbed the uptake and translocation of macro and micronutrients in the macrophyt...

The predictors of terrorism are unclear. This paper examines the effect of public opinion in one country toward another country on the number of terrorist attacks perpetrated by people or groups from the former country against targets in the latter country. Public opinion is measured by the percentage of people in Middle Eastern and North African countries who disapprove of the leadership of ni...

This article examines the effects of residential segregation on the basis of poverty status and race for high school and college completion. Segregation effects are estimated by contrasting educational outcomes among persons raised in metropolitan areas with varying levels of segregation. This metropolitan-level approach provides two advantages in evaluating segregation effects over neighborhoo...

The work group on cardiovascular and endocrine effects was asked to review the current state of knowledge about children's windows of vulnerability to developmental toxicants and to recommend how that information may be used to improve risk assessment and public health. We considered differences between structural defects, where periods of vulnerability are rather well defined, and functional d...

External finance is critical for less established entrepreneurs, so poor investor protection can hinder competition. We model how lobbying for weaker investor protection reduces access to finance and decreases competition in countries where politicians are less accountable to voters. Weaker accountability thus produces a smaller economic elite. As empirical support for this result, in a broad p...

Wind power is the fastest growing renewable energy source in the United States. Existing empirical studies on the economic impact of wind power development have primarily relied on case studies and input-output models, which have limitations. This study instead uses a linear fixed effects model to estimate the county level effects of wind power in the Great Plains region of the United States fr...

An operating system contains a replaceable unit whose wear (i.e. accumulated amount of damage) can be observed over time. When the wear reaches a certain level the unit is no longer able to function satisfactorily and needs to be replaced. Although units are produced to the same nominal specification there is still some random variation among them in their wear rates. This will be expressed by ...