Comparing the small sample properties of two break Lagrange Multiplier unit root tests

In this note, we examine the size and power properties and the break date estimation accuracy of the Lee and Strazicich (LS, 2003) two break endogenous unit root test, based on two different break date selection methods: minimising the test statistic and minimising the sum of squared residuals (SSR). Our results show that the performance of both Models A and C of the LS test are superior when one uses the minimising SSR procedure.

What factors are associated with adolescents' school break time physical activity and sedentary time?

Purpose Adolescents' physical activity levels during school break time are low and understanding correlates of physical activity and sedentary time in this context is important. This study investigated cross-sectional and longitudinal associations between a range of individual, behavioural, social and policy/organisational correlates and objectively measured school break time physical activity and sedentary time.

Methods In 2006, 146 adolescents (50% males; mean age = 14.1±0.6 years) completed a questionnaire and wore an accelerometer for ≥3 school days. Time spent engaged in sedentary, light (LPA) and moderate-to-vigorous physical activity (MVPA) during school break times (recess and lunchtime) were calculated using existing cut-points. Measures were repeated in 2008 among 111 adolescents. Multilevel models examined cross-sectional and longitudinal associations.

Results Bringing in equipment was cross-sectionally associated with 3.2% more MVPA during break times. Females engaged in 5.1% more sedentary time than males, whilst older adolescents engaged in less MVPA than younger adolescents. Few longitudinal associations were observed. Adolescents who brought sports equipment to school engaged in 7.2% less LPA during break times two years later compared to those who did not bring equipment to school.

Conclusion These data suggest that providing equipment and reducing restrictions on bringing in sports equipment to school may promote physical activity during school recess. Strategies targeting females' and older adolescents', in particular, are warranted.

Prison substance misuse programs and offender rehabilitation

This article considers the nature of the association between substance misuse and criminal behaviour and how this might inform the development of prison-based substance misuse treatment programs. The literature on what is known about the effectiveness of prison-based treatment is reviewed and the implications for correctional practice considered. It is concluded that prison-based substance misuse treatment should be considered a critical component of rehabilitation programming and that justice outcomes are likely to be improved when a number of program features are incorporated.

Has the structural break slowed down growth rates of stock markets?

In this paper, we use the common structural break test suggested by Bai et al. (1998) to test for a common structural break in the stock prices of the US, the UK, and Japan. On the basis of the structural break, we divide each country's stock price series into sub-samples and investigate whether or not the structural break had slowed down the growth of stock markets. Our main findings are that when stock markets are modelled in a trivariate sense the common structural break turns out to be 1990:02, with the confidence interval including several episodes, such as the asset price bubble when housing prices and stock prices in Japan reached a peak in 1988/1989, the early 1990s recession in the UK, the business cycle peak of July 1990, the August 1990 Iraqi invasion of Kuwait and the March 1991 business cycle trough. Annual average growth rates suggest that the structural break has slowed down the growth rate of the US, the UK and Japanese stock markets.

Size and power properties of structural break unit root tests

In this article, we compare the small sample size and power properties of a newly developed endogenous structural break unit root test of Narayan and Popp (NP, 2010) with the existing two break unit root tests, namely the Lumsdaine and Papell (LP, 1997) and the Lee and Strazicich (LS, 2003) tests. In contrast to the widely used LP and LS tests, the NP test chooses the break date by maximizing the significance of the break dummy coefficient. Using Monte Carlo simulations, we show that the NP test has better size and high power, and identifies the structural breaks accurately. Power and size comparisons of the NP test with the LP and LS tests reveal that the NP test is significantly superior.

Prison rape : is it okay to make jokes about rape in prison?

The trivialisation of sexual violence through what passes as humour is much less common than it once was. Jokes about rape are not innocent, are not harmless fun, are not unconnected to the horrible crime they make light of. Their gradual marginalisation represents social change of real importance. But there is one last refuge of the rape joke in mainstream popular culture, and its continued presence reflects a shameful blind spot in our society. It is a joke which conceals a horrible and damaging reality which is somehow both a taboo topic and a truth universally acknowledged.

A picture that circulated widely on Facebook and other social media last year captures the horror in the humour. It is a picture of a man’s back, decorated with a huge image of an alluring, naked woman, with the man’s buttocks marked to look like breasts. The caption: This man had what he thought was the best tattoo in the world . . . until he went to prison. How can a gag about a man being anally raped while in prison be widely popular, seen as funny, a giggle to share? Were the prospective victim a child or a woman, or were the rape in almost any other setting, the reaction would surely be revulsion and anger. Jail rape, though, somehow remains funny.

Crews, wusses, and whoppas: core and fringe vocabularies of Australian meal-break conversations in the workplace

Conversational samples were collected from 34 nondisabled subjects across four worksites. The total sample was analyzed for core vocabulary, and the five most frequently referenced topics were analyzed for core and fringe vocabularies and the commonality of fringe vocabulary across topics. The results indicated that there was a small stable core vocabulary of 347 words containing words unique to this study, which accounted for 78% of the conversational sample. A total of 21 words in the fringe vocabulary was common to all topics. Implications of this study for vocabulary selection for augmented communicators in employment are discussed.

Topics of meal-break conversations

Meal-break conversational samples were collected from 34 nondisabled participants across four worksites. The samples were analyzed for topics referenced and also for patterns of topics associated with days of the week. The results of the analysis indicated that the participants referenced 73 different topics. Analysis of the 10 most frequently referenced topics in each composite day file revealed 19 topics, of which 5 (i.e., work, fact finding, judgments, food, and family life) were referenced every day. Analysis of the number of communication segments in each of the 19 topics indicated that fact finding was the most frequently referenced topic, but work was the largest topic (i.e., contained the greatest number of words). There was some pattern to topic reference associated with the day of the week. Implications of this information for individuals with severe communication impairments who wish to access the work force are discussed.

(Particularly) Burdensome prison time should reduce imprisonment length — and not merely in theory

Imprisonment is the harshest sanction in our system of law. It is a sanction that isincreasingly imposed by the courts. The severity of imprisonment as a sanction stemsprincipally from the considerable restrictions it imposes on an individual’s liberty.However, the deprivation experienced by a prisoner can vary considerably, depending onthe strictness of the prison regime in which the prisoner is confined and his or her state ofhealth. Prisoners subjected to non-mainstream conditions almost invariably suffer morethan those in normal conditions. There is no settled approach regarding the extent towhich prison conditions should impact on the length of a prison term. The jurisprudencein this area is inconsistent. It is particularly unsettled when the additional burden stemsfrom subjective matters relating to an accused, such as ill health. In this article we makerecommendations regarding the manner in which prison conditions should impact on thelength of a prison term. The main recommendation is that prisoners who spend time inparticularly burdensome conditions should have their sentence reduced by a factor of0.5 days for each day spent in such conditions. In this article we also recommend thatAustralia should adopt a model similar to those which exist in some Scandinaviancountries, whereby the only deprivation stemming from imprisonment is the loss ofliberty. This would mean that few prisoners would ever be subjected to particularlyburdensome conditions. This would make many of the recommendations in this paperobsolete. However, there is no evidence that Australian prison conditions are about tofundamentally alter. Hence, the recommendations will remain pragmatically relevant inthe foreseeable future.

Testing for panel cointegration with a level break

This paper proposes four simple tests for the null hypothesis of no cointegration in the presence of a level break. The tests are general enough to allow for endogenous regressors, serial correlation and heterogeneous breaks of unknown timing. The limiting distributions of the tests are derived and critical values are provided. We also conduct a small Monte Carlo study to investigate their finite sample properties. © 2005 Elsevier B.V. All rights reserved.

The influence of incarceration length and protection status on perceptions of prison social climate

Using a 2 (incarceration length) × 2 (custody type) between-groups design, the present study assessed whether inmates’ perceptions of the prison social climate were influenced by their security classification and length of time they had been incarcerated. Analyses of data collected from 76 male prisoners who completed a 15-item measure of prison social climate revealed an interaction effect between length of incarceration and protective prisoner status. Those housed in protectivecustody who had been incarcerated for longer than 6 months rated the social climate significantly more positively than both protective custody prisoners incarcerated for less than 6 months and those not in protective custody. This interaction was strongest on those social climate dimensions relating to therapeutic hold and social cohesion. A univariate effect was also observed whereby protective custody prisoners, irrespective of incarceration length, reported that they experienced the environment as less safe than their mainstream (non-protective custody) counterparts.

Brief report: associations between self-reported paternal relationships, anger, alcohol, and intimate partner violence in a prison sample

This study investigates the association between family relationships, anger, alcohol use, and self-reported intimate partner violence (IPV). Participants were 55 male prisoners who completed a survey about their family relationships, anger, alcohol use, and aggression. Exposure to parental IPV predicted rates of self-reported perpetration of IPV, suggesting the importance of understanding more about the developmental pathways to IPV if effective prevention, intervention, and assessment strategies are to be developed for use with this high-risk population.