DISTINGUISHING FACTS AND ARTIFACTS IN GROUP-BASED MODELING*

Group-based methodology (SPGM) has been presented as suitable to test for the existence of subpopulations not directly observable. Several criminological studies have used this methodology, and it is fair to say that typological theorizing has been spurred by its development. In particular, much of the empirical support for Moffitt's taxonomy (1993, 2006) is from studies using SPGM. In a small simulation experiment, I investigate whether SPGM is suitable for such tests, and I examine the extent to which similar trajectories might equally well result from mechanisms suggested by general theories. I conclude that, as it is usually applied, SPGM cannot provide evidence either for or against a taxonomy and that the usual findings can be explained by competing theories. I argue that this result is not only because of the methodology characteristics but also because of the modeling strategy applied.     

数学建模竞赛与公安院校学生职业能力培养

分析公安院校学生参加数学建模竞赛,体会到数学建模与公安院校学生职业综合能力的培养是密不可分的,认真研究如何将数学建模思想和方法融入到公安大教育职业岗位综合能力的培养,得到一些建设性启示。     

An Experimental Test of Selectorate Theory

This article uses a laboratory experiment to test one of the main predictions of selectorate theory, that is, that democratic leaders invest more resources in public goods than autocratic leaders. The results of the experiment confirm this prediction and further show citizens are better off on average under democratic institutions than autocratic institutions. Meanwhile, autocratic leaders receive higher payoffs than democratic leaders. Additionally, this article attempts to bring domestic politics into international relations experimentation with a focus on how communication may allow democracies to organize more efficiently for war than autocracies. A game theoretical model shows democracies have the potential to organize optimally and use their citizens’ skills to their full advantage while autocracies do not. The results of the experiment reveal some evidence that democracies organize more efficiently than autocracies, but that this increased efficiency did not produce a higher percentage of conflict wins.     

Alcohol Use, Outcome Expectancies, and HIV Risk Status among American Indian Youth: A Latent Growth Curve Model with Parallel Processes

Alcohol use is cited as a risk factor for exposure to HIV infection through risky sexual behavior, especially among adolescents. From Social Cognitive Theory, positive outcome expectancies about the use of alcohol have often been presented as a critical aspect of alcohol use. Yet little is known about how they might be related to different aspects of HIV risk. Using latent growth curve modeling with data from 292 American Indian youth across seven years, both alcohol use and positive expectancies increased significantly; a lower-risk group showed significantly slower increases in both. Changes in alcohol use and outcome expectancies were significantly interrelated, providing support for reciprocal influence between the two constructs. Positive alcohol outcome expectancies may provide a preventive intervention point worthy of further consideration as influencing alcohol use and lowering HIV sexual risk among adolescents.Associate Professor at the University of Colorado at Denver and Health Sciences Center. She received her Ph.D. in Community Psychology from Michigan State University. Her major research interests are adolescent development among minority youth with an emphasis on positive and problem behaviors.Associate Professor at the University of Colorado at Denver and Health Sciences Center. She received her Ph.D. in Social Psychology from the University of Michigan. Her major research interests are in areas of American Indian mental health and services research.Assistant Professor at the University of Colorado at Denver and Health Sciences Center. She received her Ph.D. in Sociology from the University of Michigan. Her primary research interests are in demography and contextual effects of individual health behavior, with a special emphasis on adolescent development.In addition to the above people, the Project Team included Sonia Bauduy, Cathy A.E. Bell, Cecelia K. Big Crow, Dedra Buchwald, Nichole Cottier, Amy D. Dethlefsen, Ann Wilson Frederick, Ellen M. Keane, Shelly Hubing, Natalie Murphy, Angela Sam, Jennifer Settlemire, Jennifer Truel, and Frankee White Dress.     

Perceived Sibling Relationships and Adolescent Development

Utilizing longitudinal, 3-wave data collected from multiple informants (fathers, mothers, and target children) in 374 families, the potential effects of sibling relationships on adolescent development across early and middle adolescence were investigated. Adolescents who perceived their sibling relationships more positively at Time 1 tended to have better friendships and higher self-esteem at Time 2, which, in turn, were associated with less loneliness, less depression, and fewer delinquent behaviors and less substance use at Time 3. Moreover, a bidirectional relationship was found between adolescent self-esteem and the quality of their sibling relationships, suggesting that a more positive sibling relationship helps to enhance adolescent self-esteem, and that higher adolescent self-esteem predicts a more positive sibling relationship. A bidirectional relationship was also found between adolescent sibling relationships and adolescent friendships. However, a much stronger association between adolescent sibling relationships at Time 1 and adolescent friendships at Time 2, than between adolescent friendships at Time 1 and adolescent sibling relationships at Time 2, may suggest that the quality of an earlier sibling relationship is more predictive of the quality of a later friendship for adolescents rather than the other way around.     

Work-Life Balance and National Context in Attraction to Public Employment

What explains preferences for public employment versus private business employment. Much of the extant literature considers this topic within the context of single-nation studies and the work motives of those individuals already employed by government. This study contributes to the public-management literature with a cross-national examination of government employment preferences across 31 national samples using data from the International Social Survey Programme. Results indicate that a desire for more work-life balance is negatively associated with a preference for government employment and that measures of national economic health help explain the variation in preferences for government employment across nations.     

Effects of Deviant Peer Association on Adolescent Alcohol Consumption: A Growth Mixture Modeling Analysis

This study examined concurrent and lagged effects of deviant peer association on levels of alcohol use for distinctive trajectories of drinking from ages 14–18 years, while controlling for age, paternal education, community size, and conduct problems. Longitudinal data were available from a secondary data archive of male and female German adolescents (N = 1,619). Conditional latent growth mixture modeling analysis indicated consistent concurrent effects of deviant peer association (specified as time-varying covariate) on alcohol use for the regular users group, but not any of the other drinking trajectory groups. Very few lagged effects of deviant peers association on alcohol use were found, and thus the social influence hypothesis received little empirical support. Overall, findings suggest the need to consider heterogeneity in the study of peer characteristics and alcohol use for both male and female adolescents.

论数学方法在经济学中的运用

本文主要讨论了涉及数学方法在经济学中运用的两个问题。论文认为:首先,经济学的性质和经济研究所设定的前提决定了数学方法的适用范围,而经济理论前提假设的正确性决定了数学模型的正确性。其次,在马克思主义的经济学研究中采用适当的数学分析工具不仅可以清晰地阐明理论的核心含义,而且有助于更清晰地找到马克思主义与其他理论的本质差异在什么地方。为了正确地把握经济研究对象的性质和发展趋势,必须把数理研究方法和历史的方法有机地结合起来。     

International Signaling and Economic Sanctions

Do economic sanctions serve international signaling purposes? A fully structural statistical model that employs a signaling game as a statistical model is used to investigate the existence of signaling effects of sanctions. Estimation results suggest that sanctions fail to work as a costly signal. The cheapness of sanctions prevents a target state from being able to distinguish a resolute sender state from a sender who is bluffing. When sanctions are imposed, a target rarely updates its initial evaluation of the sender state’s resolve, much less than when a military challenge is observed.     

BITING ONCE,TWICE: THE INFLUENCE OF PRIOR ON SUBSEQUENT CRIME LOCATION CHOICE

Properties, victims, and locations previously targeted by offenders have an increased risk of being targeted again within a short time period. It has been suggested that often the same offenders are involved in these repeated events and, thus, that offenders’ prior crime location choices influence their subsequent crime location choices. This article examines repeated crime location choices, testing the hypothesis that offenders are more likely to commit a crime in an area they previously targeted than in areas they did not target before. Unique data from four different data sources are used to study the crime location choices of 3,666 offenders who committed 12,639 offenses. The results indicate that prior crime locations strongly influence subsequent crime location choices. The effects of prior crime locations are larger if the crimes are frequent, if they are recent, if they are nearby, and if they are the same type of crime.