Statistics in Latin America

Statistics is a relatively new discipline in Latin America. At present only sparse information is available about the state of the statistical profession in Latin America. We present and summarize the available information about the job market; training, education, and research; professional societies and their activities; and so forth. We also share our hopes, concerns, and suggestions for the future.     

Testing for abrupt breaks in variance structures with smooth changes

Abstract

We investigate the problem of testing for variance breaks in the case where the variance structure is assumed to be smoothly time-varying under the null. Since the classical tests are aimed to detect any change in the variance, they are not able to distinguish between smooth non constant variance and abrupt breaks. In this paper a new procedure for detecting variance breaks taking into account for smooth changes in the variance under the null is proposed. The finite sample properties of the test we introduce are investigated by Monte Carlo experiments. The theoretical outputs are illustrated using U.S. macroeconomic data.     

The sample monomode and an associated test for discrete monomodality

Abstract

The notions of (sample) mean, median and mode are common tools for describing the central tendency of a given probability distribution. In this article, we propose a new measure of central tendency, the sample monomode, which is related to the notion of sample mode. We also illustrate the computation of the sample monomode and propose a statistical test for discrete monomodality based on the likelihood ratio statistic.     

Investigation of the diesel consumption for trucks at an overburden stripping area by SPC study

This study examined whether diesel consumption used by trucks at a stripping area is controlled or not. The factors affecting diesel consumption were also investigated and some necessary solutions were presented. Diesel consumption was observed with the aid of control graphs. Abnormal situations in the diesel consumption were explored by means of Shewhart control graphs. The factors which are out of control were also presented in a cause–effect diagram, and suggestions for improvement were proposed. It has been determined that the main effect of the diesel consumption is the daily run number of the trucks. The main factors affecting the daily run number were also investigated.     

DDP—Managerial opportunities and consequences

Applications of DDP are examined via two case studies to determine how the technology was used by management to aid decision-making; the level of management involvement in the MIS (Management Information Systems) design process and the nature of the relationship between managers and data processing departments were also considered. The study showed that because the technology was largely under end user control, better tailored information systems resulted and system output was more directly used by middle and top managers. This only occurred, however, if certain moderators, such as computing and modelling skills, were present in functional departments. DDP also offers opportunities for better relationships with data processing departments but the consequences include the need for better management training and functional support groups for systems implementation. A conceptual model is presented as a theoretical framework to guide organisations when using DDP.     

Followers and leaders: Reciprocity,social norms and group behavior

This paper proposes a model of norm-driven preferences and studies the determinants of norm compliance in games. It predicts that (i) compliance follows a law of demand and (ii) people respect norms in a reciprocal manner: they are more likely to comply if others are expected to comply too. Reciprocal norm compliance might explain why successful revolutions or strikes grow in a snow-balled fashion, leaders motivate others to join social movements, or sequential mechanisms (instead of simultaneous ones) are usually employed in charity fundraising.     

Retirement migration and transnationalism in northern Mexico

This article examines the phenomenon of transnationalism among retired immigrants living in border areas of northern Mexico. Using in-depth interviews conducted with US retirees residing in Baja California, Mexico, we seek to examine how transnational aging is constructed through different practices, relationships, networks and exchanges between both cultures and countries. We analyse several analytical dimensions of transnationalism including social, economic, cultural, identity and belonging conditions. In particular, networks and exchanges among these elderly migrants are most frequently constructed across social and family networks, economic transfers, access to healthcare, and culture. Additionally, we find that these maintained transnational practices in northern Mexico parallel those of international retired migrants living in other parts of the world. However, we argue that the proximity to the US border enables and encourages many types of connections of varying intensities. Finally, we discuss the implications for future research linking transnationalism with international retirement migration.     

Suicidal behavior and associated factors in sexually abused adolescents

Objectives

The aim of the present study is to determine the rate of suicidal ideation and suicide attempts in sexually abused adolescents and to determine the factors associated with suicidal behavior.

Method

106 adolescents between the ages of 12–18 (94 girls, 12 boys) who were exposed to sexual abuse and referred for the preparation of forensic reports were included in the study. The investigators retrospectively examined the case files, forensic reports and social worker reports.

Results

It has been found that in cases exposed to sexual abuse, suicidal ideation developed in 63.2% (n = 67) of the individuals and 24.5% (n = 26) of them attempted suicide. The rate of suicidal ideation and suicide attempts was higher in cases who live separately from one or both parents, those who have ASD or PTSD after sexual abuse, cases in which abuse involved penetration, cases who were abused by someone known or someone from the family, cases where sexual abuse was accompanied by coercion and physical violence, and those who were exposed to abuse continuously. Among girls, in cases who have suicide history before sexual abuse and those who were abused by more than one abuser, the rate of suicidal ideation was higher.

Conclusion

It has been shown in many studies that sexual abuse in childhood increases the risk of suicidal behavior. Consideration of the factors associated with suicidal behavior in victims of sexual abuse will be helpful to clinicians in preventing suicide attempts.     

Impact of Gender and the Stereotyped Nature of Illustrations on Choice of Color: Replica of the Study by Karniol (2011) in a Spanish Sample

Early acquisition of stereotypes that associate “blue” with boys and “pink” with girls can influence their preferences for these colors and also their choices in clothing, toys or objects in relation to gender stereotypes. In a Spanish sample (5–10-year olds, n = 614), this study reproduces the previous research conducted by Karniol (Sex Roles 65(1/2):119–132, 2011) for the purpose of analyzing whether gender-linked color preferences rule the choice of coloring booklets and if children’s choices of color are affected by their own gender. The results show that although boys used fewer female-stereotyped colors than girls, both genders colored in each figure with the stereotyped colors associated with them. This result indicates that boys and girls share similar gender stereotypes and use colors that agree with these stereotypes.