Dimensions of Problem Gambling Behavior Associated with Purchasing Sports Lottery

The purpose of this study was to identify and examine the dimensions of problem gambling behaviors associated with purchasing sports lottery in China. This was accomplished through the development and validation of the Scale of Assessing Problem Gambling (SAPG). The SAPG was initially developed through a comprehensive qualitative research process. Research participants (N = 4,982) were Chinese residents who had purchased sports lottery tickets, who responded to a survey packet, representing a response rate of 91.4%. Data were split into two halves, one for conducting an EFA and the other for a CFA. A five-factor model with 19 items (Social Consequence, Financial Consequence, Harmful Behavior, Compulsive Disorder, and Depression Sign) showed good measurement properties to assess problem gambling of sports lottery consumers in China, including good fit to the data (RMSEA = 0.050, TLI = 0.978, and CFI = 0.922), convergent and discriminate validity, and reliability. Regression analyses revealed that except for Depression Sign, the SAPG factors were significantly (P < 0.05) predictive of purchase behaviors of sports lottery. This study represents an initial effort to understand the dimensions of problem gambling associated with Chinese sports lottery. The developed scale may be adopted by researchers and practitioners to examine problem gambling behaviors and develop effective prevention and intervention procedures based on tangible evidence.     

Bayesian Interval Estimation for the Difference in TPRs and FPRs of Two Diagnostic Tests with Unverified Negatives

We derive Bayesian interval estimators for the differences in the true positive rates and false positive rates of two dichotomous diagnostic tests applied to the members of two distinct populations. The populations have varying disease prevalences with unverified negatives. We compare the performance of the Bayesian credible interval to the Wald interval using Monte Carlo simulation for a spectrum of different TPRs, FPRs, and sample sizes. For the case of a low TPR and low FPR, we found that a Bayesian credible interval with relatively noninformative priors performed well. We obtain similar interval comparison results for the cases of a high TPR and high FPR, a high TPR and low FPR, and of a high TPR and mixed FPR after incorporating mildly informative priors.     

Pay comparability in state governments

Earnings differentials between state government and private industry employees are estimated for each state using 1990 Census data. Female employees in most state governments receive higher earnings than comparable private sector employees, whereas the opposite result applies to males. However, the size of the state government earnings advantage or penalty is not uniform across states for either sex. The relative earnings of state employees increase with their membership in unions and with the revenues generated by state government’s tax and financing policies.     

On the Use of Hierarchical Probabilistic Models for Characterizing and Managing Uncertainty in Risk/Safety Assessment

A general probabilistically-based approach is proposed for both cancer and noncancer risk/safety assessments. The familiar framework of the original ADI/RfD formulation is used, substituting in the numerator a benchmark dose derived from a hierarchical pharmacokinetic/pharmacodynamic model and in the denominator a unitary uncertainty factor derived from a hierarchical animal/average human/sensitive human model. The empirical probability distributions of the numerator and denominator can be combined to produce an empirical human-equivalent distribution for an animal-derived benchmark dose in external-exposure units.     

Habitat use and activity patterns of urban-dwelling javelina

In Arizona, conflicts between homeowners and urban-dwelling javelina (Tayassu tajacu) continued to increase. Human-javelina conflicts often occurred when javelina responded to urban attractants and destroyed ornamental landscapes, injured pets, and frightened homeowners. This prompted initiation of a study during 1992–93 to develop recommendations to alleviate these conflicts. We captured, radio-collared, and located eight javelina from six herds to determine home ranges, habitat use, and activity patterns in Prescott, Arizona. Urban-dwelling javelina adjusted their home ranges, habitat use, and activity patterns to best use human-provided urban food, water, and cover resources. The most conspicuous of these adjustments was the increased nocturnal activity of urban-dwelling javelina to avoid human disturbances. Undeveloped land within or adjacent to Prescott provided javelina with daytime bedding areas and nighttime travel corridors. We determined that this issue was more a people problem than it was a javelina problem. Thus, strategies to resolve the conflicts must target homeowners.     

Normalization in Econometrics

The issue of normalization arises whenever two different values for a vector of unknown parameters imply the identical economic model. A normalization implies not just a rule for selecting which among equivalent points to call the maximum likelihood estimate (MLE), but also governs the topography of the set of points that go into a small-sample confidence interval associated with that MLE. A poor normalization can lead to multimodal distributions, disjoint confidence intervals, and very misleading characterizations of the true statistical uncertainty. This paper introduces an identification principle as a framework upon which a normalization should be imposed, according to which the boundaries of the allowable parameter space should correspond to loci along which the model is locally unidentified. We illustrate these issues with examples taken from mixture models, structural vector autoregressions, and cointegration models.     

Infants' Reactions to Object Collision on Hit and Miss Trajectories

This experiment investigated the impact of the path of approach of an object, from head on versus from the side, and the type of imminent contact with that object, a hit versus a miss, on young infants' perceptions of object looming. Consistent with earlier studies, we found that 4‐ to 5‐month‐old infants do indeed discriminate hits versus misses. We also found a novel result regarding the path of the approaching object. The discrimination of hits from misses was modified by whether or not the approaching objects passed in front of the infants' faces; objects crossing the line of sight evoked more frequent defensive reactions than objects that did not cross the line of sight, regardless of whether or not such objects were on a collision course. These findings are discussed within the context of the development of visually guided locomotion and linear versus nonlinear paths of translation through the world.