The fertility effect of catastrophe: U.S. hurricane births

Anecdotal evidence has suggested increased fertility rates resulting from catastrophic events in an area. In this paper, we measure this fertility effect using storm advisory data and fertility data for the Atlantic and Gulf-coast counties of the USA. We find that low-severity storm advisories are associated with a positive and significant fertility effect and that high-severity advisories have a significant negative fertility effect. As the type of advisory goes from least severe to most severe, the fertility effect of the specific advisory type decreases monotonically from positive to negative. We also find some other interesting demographic effects.     

Forecasting for Resources in Forestry and Marine Fisheries in the Year 2000

Forestry and fisheries are major industries using renewable living resources. The resources have in common principles of ecology that control productivity, but there are differences in the time scales and dynamics of productivity that affect the management and economics of harvesting. These differences lead to the need for different approaches to forecasting the supply and possible yields. The factors that need to be considered in developing forecasts are described with examples of application.     

A Survey of Microcomputer Survival Analysis Software: The Need for an Integrated Framework

This paper surveys commercially available MS-DOS and Microsoft Windows based microcomputer software for survival analysis, especially for Cox proportional hazards regression and parametric survival models. Emphasis is given to functionality, documentation, generality, and flexibility of software. A discussion of the need for software integration is given, which leads to the conclusion that survival analysis software not closely tied to a well-designed package will not meet an analyst's general needs. Some standalone programs are good tools for teaching the theory of some survival analysis procedures, but they may not teach the student good data analysis techniques such as critically examining regression assumptions. We contrast typical software with a general, integrated, modeling framework that is available with S-PLUS.     

Longitudinal data analysis of animal growth via multivariate dynamic models

We propose models to analyze animal growth data with the aim of estimating and predicting quantities of biological and economical interest such as the maturing rate and asymptotic weight. It is also studied the effect of environmental factors of relevant influence in the growth process. The models considered in this paper are based on an extension and specialization of the dynamic hierarchical model (Gamerman & Migon, 1993) to a non–linear growth curve setting, where some of the growth curve parameters are considered exchangeable among the units. The inference for these models are approximate conjugate analysis based on Taylor series expansions and linear Bayes procedures     

Are there rewards for language skills? Evidence from the earnings of registered nurses

The existing empirical evidence on whether U.S. labor markets reward workers for second-language skills is meager and conflicting. Employing data from the National Sample Survey of Registered Nurses in 2000 and 2004, this study reexamines the positive bilingual–earnings relationship found in the most current research on this topic. We test the relationship using alternative models that explain the wages earned by nurses. The advantage of this approach is that it permits an assessment of how sensitive the results are to changes in the variables used in the model. We find the evidence of a positive bilingual effect on earnings to be mixed. The relationship is sufficiently frail that statistically significant results eventually dissolve as more precise occupational characteristics are included in the wage equation. Moreover, using more current data, we find no evidence of a wage premium paid to nurses for second-language skills. We offer possible explanations for this lack of evidence within this specific occupation.