The Muscatine children's obesity data reanalysed using pattern mixture models

A set of longitudinal binary, partially incomplete, data on obesity among children in the USA is reanalysed. The multivariate Bernoulli distribution is parameterized by the univariate marginal probabilities and dependence ratios of all orders, which together support maximum likelihood inference. The temporal association of obesity is strong and complex but stationary. We fit a saturated model for the distribution of response patterns and find that non-response is missing completely at random for boys but that the probability of obesity is consistently higher among girls who provided incomplete records than among girls who provided complete records. We discuss the statistical and substantive features of, respectively, pattern mixture and selection models for this data set.     

Native American casino gambling in Arizona: A case study of the Fort McDowell reservation

Since Congress passed the American Indian Gambling Regulatory Act (IGRA) in 1988, there has been an explosion in the number of gambling casinos located on Native American reservations. It is estimated that in 1994 the total net revenue from 81 Native American casinos exceeded $2.3 billion dollars. As the number of Native American casinos grows along with the volume of gambling activity, opposition increases from states, the established gambling industry hurt by lost revenues, and groups with moral objections to gambling. This article reports on an effort to measure the economic impact of the Fort McDowell casino located near Phoenix, Arizona. The article discusses the casino's history and current operations. Next, it explains the use of an input-output model to compute the impact of casino's income and employment effects on the economy of Maricopa County. It is estimated that the casino is responsible for 2,483 new jobs, and an increase of approximately $80.35 million in regional output. Additional information is necessary to more accurately assess both the benefits and costs of the casino. Unfortunately, subsequent efforts to collect additional data have been unsuccessful. The conclusion discusses why, and raises questions regarding Native American gaming.An earlier version of this paper was presented at the 9th International Conference on Gambling and Risk Taking, May 31–June 3, 1994, Las Vegas, Nevada. This research was funded by a FGIA grant from Arizona State University. The author expresses his appreciation to the referees who provided substantial guidance in improving the original paper. Any remaining errors are mine.     

The relative risk aversion hypothesis of educational choice

Analysing young people's educational choices, we derive and test implications of a relative risk aversion hypothesis: that educational choices are made so as to minimize the risk of ending up with a lower level of education than one's parents. These implications are in general different from what one would expect from human capital theory. We use a unique data set which combines data from administrative registers on young people's pathways through the educational system and their family background with survey data on their academic abilities at lower secondary school. The evidence is partly in favour of the relative risk aversion hypothesis. Received: 19 August 1999/Accepted: 10 January 2001 All correspondence to Eskil Heinesen. We are grateful to Karin Blix Mogensen and Martin B?g for excellent research assistance, and to two anonymous referees, John F. Ermisch, Martin Browning, Michael Rosholm, Paul Bingley, and participants at the conference of the European Society for Population Economics in Turin, 1999, for valuable comments and suggestions. Responsible editor: John F. Ermisch.     

The militarization of Native America: Historical process and cultural perception

Native Americans have experienced widespread militarization as the result of a number of factors. First, many Mative nations militarized in reaction to the weaponry and threats presented by invading Europeans. Secondly, the Europeans and later the Americans used Native Americans as auxiliaries and allies in their wars against other Native nations. Finally, militarization came to several tribes by way of the U.S. policy of assimilating American Indians into mainstream American society. Militarization, in short, became a way of legitimating Native citizenship. Many Indians, however, look upon their military service in a different way. Native American militarization resembles that of the Nepalese Gurkha veterans of the British Army.     

Breakdown of teenage placements in Danish out‐of‐home care

This study deals with the problem of breakdown in out‐of‐home placements for Danish teenagers. How often are these placements prematurely terminated against the requests and intentions of the child welfare authorities? Which factors seem to increase and decrease placement breakdown? The sample consists of 225 youths and 367 placements during the years 2004–2008. Among the 225 youths, 44% experienced a breakdown, and 33% of the 367 placements ended with a breakdown. A large proportion of the placement breakdowns (20%) occurred before 4 months, and within the first year, 62% of the placement breakdowns had taken place. Replacements took place in 61% of all placement breakdowns. The analysis showed that type of placement and number of youth at the same placement had significant association to placement breakdown, but variables based on the social worker's clinical assessment showed no association to breakdown. However, while the logistic regression model was significant, it explained only 6% of the variance. Earlier studies have indicated that breakdown is a substantial problem of child welfare in several other western countries, Denmark is no exception. These corresponding breakdown rates point out that no child welfare system yet have found a method to reduce breakdown substantially.     

Are transformational and laissez-faire leadership related to state anxiety among subordinates? A two-wave prospective study of forward and reverse associations

ABSTRACT

The aim of this study was to determine the direction of associations between perceived leadership styles of an immediate leader and state anxiety among subordinates using time-lagged data from a large and heterogeneous probability sample of Norwegian employees. It was hypothesised that high levels of transformational leadership would be associated with a decrease, whereas high levels of laissez-faire leadership would be associated with an increase, in subsequent levels of anxiety. Reciprocal associations were also expected in that higher levels of anxiety were hypothesised to be related to subsequent increase in reports of laissez-faire, and decrease in reported exposure to transformational leadership. The sample comprised 1149 Norwegian employees. The design was a two-wave full panel study with a six-month time interval between the baseline and follow-up assessments. Contrary to hypotheses, neither transformational nor laissez-faire leadership were significantly related to subsequent levels of state anxiety. In support of hypotheses, baseline low levels of state anxiety were associated with reporting the immediate leader as less transformational and more laissez-faire six months later. In conclusion, the findings challenge theoretical models that explain leadership as a one-way superior–subordinate influence process.     

Bootstrap Confidence Intervals for Large-scale Multivariate Monotonic Regression Problems

Recently, the methods used to estimate monotonic regression (MR) models have been substantially improved, and some algorithms can now produce high-accuracy monotonic fits to multivariate datasets containing over a million observations. Nevertheless, the computational burden can be prohibitively large for resampling techniques in which numerous datasets are processed independently of each other. Here, we present efficient algorithms for estimation of confidence limits in large-scale settings that take into account the similarity of the bootstrap or jackknifed datasets to which MR models are fitted. In addition, we introduce modifications that substantially improve the accuracy of MR solutions for binary response variables. The performance of our algorithms is illustrated using data on death in coronary heart disease for a large population. This example also illustrates that MR can be a valuable complement to logistic regression.     

Asymptotic Inference for Waiting Times and Patiences in Queues with Abandonment

Motivated by applications in call center management, we propose a framework based on empirical process techniques for inference about waiting time and patience distributions in multiserver queues with abandonment. The framework rigorises heuristics based on survival analysis of independent and identically distributed observations by allowing correlated waiting times. Assuming a regenerative structure of offered waiting times, we establish asymptotic properties of estimators of limiting distribution functions and derived functionals. We discuss construction of bootstrap confidence intervals and statistical tests, including a simple bootstrap two-sample test for comparing patience distributions. A small simulation study and a real data example are presented.     

Quantification of symmetry for functional data with application to equine lameness classification

This paper presents a study on symmetry of repeated bi-phased data signals, in particular, on quantification of the deviation between the two parts of the signal. Three symmetry scores are defined using functional data techniques such as smoothing and registration. One score is related to the L ₂-distance between the two parts of the signal, whereas the other two are constructed to specifically measure differences in amplitude and phase. Moreover, symmetry scores based on functional principal component analysis (PCA) are examined. The scores are applied to acceleration signals from a study on equine gait. The scores turn out to be highly associated with lameness, and their applicability for lameness quantification and detection is investigated. Four classification approaches turn out to give similar results. The scores describing amplitude and phase variation turn out to outperform the PCA scores when it comes to the classification of lameness.