Identification of vector AR models with recursive structural errors using conditional independence graphs

In canonical vector time series autoregressions, which permit dependence only on past values, the errors generally show contemporaneous correlation. By contrast structural vector autoregressions allow contemporaneous series dependence and assume errors with no contemporaneous correlation. Such models having a recursive structure can be described by a directed acyclic graph. We show, with the use of a real example, how the identification of these models may be assisted by examination of the conditional independence graph of contemporaneous and lagged variables. In this example we identify the causal dependence of monthly Italian bank loan interest rates on government bond and repurchase agreement rates. When the number of series is larger, the structural modelling of the canonical errors alone is a useful initial step, and we first present such an example to demonstrate the general approach to identifying a directed graphical model.     

Preservation versus motorized recreation: Institutions, history, and public lands management

The management of the public lands in the United States has been shaped by the long-running conflict between environmental and utilitarian values. Recently, changing social expectations have increased demand for motorized recreational use and access. Critics contend such use of the public lands is a threat to their ecological health. Yet even as motorized use draws increased scrutiny and challenge, some commentators conclude that the battle is already over—and recreational users have won. This article focuses attention on the U.S. Forest Service and National Park Service and contends they are predisposed as institutions to favor demands for motorized recreational use and access. It concludes that what is needed is an explanation that seeks to place motorized recreational use in a historical and institutional context that offers a more complete understanding of why such users might be winning the battle.     

`Quantitative' and `Qualitative' Research: An Analysis

It is widely believed that there is a clear distinction between `quantitative' and `qualitative' research, and these embedded or institutionalised terms profoundly affect the practice of such research. In this article the clarity and/or usefulness of the distinction is challenged together with the whole idea that there are given `methodologies' for research. Almost everything turns on conceptual clarity in relation to the initial research-questions: that leads the research to methods which follow logically from the concepts involved. The alleged `quantitative'/`qualitative' distinction does no more than pre-empt methods and procedures of research which should be left open.     

Social inclusion under Labor in South Australia

Social inclusion policies were championed by the former Rann Labor government in South Australia from 2002 to 2011. In 2011 the Social Inclusion Unit was dissolved by the South Australian government. It is argued that the relatively narrow focus of the former SIU on ‘problem’ communities limited its capacity to provide more than residual solutions. The diminishing political returns on social inclusion also encouraged the South Australian government to abandon this initiative. In 2014 this government has had to grapple with the end of car making in Australia and a declining manufacturing labour force, traditionally a ‘mainstream’ constituency of the Labor Party. The return to ‘mainstreaming’ social policy in South Australia might offer limited space for realignment of social policy with the concept of social citizenship. It might also represent a move away from the functionalist morality of social inclusion. Social inclusion as practiced in South Australia has limited capacity to address generalised social disadvantage. The latter is likely to concern a re‐elected Labor minority government grappling with significant job losses and a declining local economy.     

Formative evaluation of a motivational intervention for increasing physical activity in underserved youth

The present study was designed to develop an innovative motivational intervention (based on Self-Determination Theory and Social Cognitive Theory) to increase physical activity (PA) in underserved adolescents. Sixty-four adolescents (35 females, 29 males; 50% minority; 65% on reduced lunch program; ages 11-13 yr) participated in either an 8-week motivational intervention after-school (n = 32) or a typical after-school program (n = 32). The conceptual framework for the intervention targeted the social environment (perceived autonomy, perceived social support, participation, fun), cognitive mediators (perceived choice, self-efficacy, and relatedness/belongingness), and motivational orientation (intrinsic motivation, commitment, positive self-concept). Formative evaluation data was collected by staff through daily forms throughout the 8-week program and through observational data completed by independent objective observers during 2 weeks of the program. The major themes that were identified addressed theoretical concepts regarding the intervention and logistical issues in delivering the intervention. The data revealed information regarding the importance of the cognitive appropriateness of the PA and motivational activities, the environmental climate for promoting nurturing relationships, developing specific strategies for increasing intrinsic rather than extrinsic reinforcement, and developing methods for preventing social "cliques" and gender conflicts to maintain an appropriate level of support in the social climate. Themes for training staff included focusing on team building, leadership, and nurturing. This formative evaluation is being used to formalize a randomized trial to test the effects of a student-centered motivational intervention on increasing PA in underserved 6th graders.     

Awareness and use of a university recreational trail

The purpose of this study was to assess awareness and use of a university recreational trail. The authors used an Internet questionnaire developed by the university's Institutional Research Department, with questions derived from the Environmental Supports for Physical Activity Questionnaire and the National College Health Risk Behavior Survey Physical Activity Module. Four hundred and sixty-seven undergraduate college students participated. Ninety-one percent of students reported being aware of the trail, and 73% reported using the trail. Sixty-four percent of students reported seeing signage referring to the recreational trail. Sixty-seven percent of the students reported using the trail once in the past week, 7% reported using the trail twice in the past week, and only 2% of the students reported using the trail more than 3 times in the past week. Sixty-two percent reported using the trail with another individual. Students who were aware of the trail were more likely to use the trail. However, of the individuals who used the trail, the majority only used the trail 1 day a week. University programming is needed to increase trail usage among college students.     

On Forward Induction

A player's pure strategy is called relevant for an outcome of a game in extensive form with perfect recall if there exists a weakly sequential equilibrium with that outcome for which the strategy is an optimal reply at every information set it does not exclude. The outcome satisfies forward induction if it results from a weakly sequential equilibrium in which players' beliefs assign positive probability only to relevant strategies at each information set reached by a profile of relevant strategies. We prove that if there are two players and payoffs are generic, then an outcome satisfies forward induction if every game with the same reduced normal form after eliminating redundant pure strategies has a sequential equilibrium with an equivalent outcome. Thus in this case forward induction is implied by decision‐theoretic criteria.