A method for estimating age-specific reference intervals ('normal ranges') based on fractional polynomials and exponential transformation

The age-specific reference interval is an important screening tool in medicine. Put crudely, an individual whose value of a variable of interest lies outside certain extreme centiles may be suspected of abnormality. We propose a parametric method for constructing such intervals. It provides smooth centile curves and explicit formulae for the centile estimates and for standard deviation (SD) scores (age-standardized values). Each parameter of an exponential–normal or modulus–exponential–normal density is modelled as a fractional polynomial function of age. Estimation is by maximum likelihood. These three- and four-parameter models involve transformations of the data towards normality which remove non-normal skewness and/or kurtosis. Fractional polynomials provide more flexible curve shapes than do conventional polynomials. The method easily accommodates binary covariates facilitating, for example, parsimonious modelling of age- and sex-specific centile curves. A method of calculating precision profiles for centile estimates is proposed. Goodness of fit is assessed by using Q–Q -plots and Shapiro–Wilk W -tests of the SD scores, and likelihood ratio tests of the parameters of an enlarged model. Four substantial real data sets are used to illustrate the method. Comparisons are made with the semiparametric LMS method of Cole and Green.     

The effects of parental leave extension on training for young women

Using three datasets for West Germany, we estimate the effect of the extension of parental leave from between 10 and 18 to 36 months on young women’s participation in job-related training. Specifically, we employ difference-in-differences identification strategies using control groups of older women and young and older men. We find that parental leave extension negatively affects job-related training for young women, even if they do not have children, especially when the focus is on employer-arranged training. There is tentative evidence that young women partly compensated for this reduction in employer-arranged training by increasing training on their own initiative.     

Efficiency of Betting Markets and Rationality of Players: Evidence from the French 6/49 Lotto

We analyse the existence of preferred numbers on the French Lotto market and prove that this market is not strongly efficient in the sense of Thaler & Ziemba (1988). The preference for low numbers is investigated by means of stochastic dominance tests. The specific features of the French Lotto game allow us to build a simple estimate of the probability distribution of numbers actually played. The results are compared with the (highly time-consuming) maximum likelihood estimator used by Farrell et al. (2000). It is shown that the two methods give very close results. Our conclusions stress the perspectives of this study in various domains.     

Communicating Under Section 112(r) of the Clean Air Act Amendments

Regulations under Section 112(r) of the 1990 Clean Air Act Amendments require fixed facilities having threshold quantities of materials on the U.S. Environmental Protection Agency's list of regulated substances to disclose to the general public the expected offsite consequences of worst-case accidental chemical releases. This paper describes the communication practices of small firms in Delaware and New Jersey and the practical problems these facilities might encounter complying with the proposed rule. The paper reports an interesting difference between the apprehension voiced by small firms required to report worst-case release information and the public's apparent lack of interest in such information. Unlike the difficulty expected by small firms in calculating and communicating worst-case chemical release information, this paper includes some observations on the ability of large chemical firms to comply with the proposed requirements.     

Residents' Efforts at Neighborhood Stabilization: Facing the Challenges of Inner-City Neighborhoods

This paper examines the response of residents in one inner-city, racially, and economically diverse neighborhood to a sudden increase in crime, drugs and disorder. Rather than withdrawing, residents in this neighborhood responded by organizing a major collective effort to develop a stabilization plan for the neighborhood. Factors useful in understanding this atypical response include a citywide structure that encourages citizen participation, the city government's commitment to the neighborhood, a history of neighborhood activism, and residents' commitment to the neighborhood. A social movement perspective that examines the nature of successful social movement organizations, the political context of movement activities, and micromovement processes is useful in analyzing cases of neighborhood activism.     

Determinants of compensation: A study of pay,performance, and gender differences for fundraising professionals

This study examines the determinants of compensation for fundraising professionals by addressing the following research questions: (1) Is there a significant pay‐performance relationship? (2) What are the factors that affect bonus and salary? (3) Is there a gender‐pay gap for individuals who are in the role of fundraisers? Data were collected over a four‐year period from a national sample of fundraising professionals employed across all industry classifications. Amount of money raised was the primary performance variable of interest. Bivariate tests for differences between males and females, as well as two‐stage simultaneous regressions, were used to determine the effects of fundraising performance on the pay of fundraisers. Results indicated a significant and positive pay‐performance linkage across all fundraising positions, particularly for chief development officers, as well as a consistent gender‐pay gap across fundraising positions.