ON THE SOLUTION OF SPATIAL EQUILIBRIUM MODELS*

Recent advances in mathematical programming methods and computing technology have the potential for overcoming the many formidable barriers to the widespread solution of nonlinear spatial models. In particular, the recent public availability of the software package MINOS/AUGMENTED has major implications for both policy and theoretical research involving spatial models. In this paper, mathematical programming formulations of two highly nonlinear spatial models are provided, model solutions presented, and associated computational experience discussed. In addition, related work is discussed briefly and suggestions are advanced concerning the potential role of the package in furthering the objectives of this related work. Subject Areas: Mathematical Programming, Transportation, and Urban and Regional Planning.     

Racial Disparities in Early Criminal Justice Involvement

Criminologists have long reported the existence of racial disparity in the criminal justice system, but the important question is why. While some argue that observed differences are a consequence of more criminal behavior among minorities, the weight of the evidence indicates that this is but a partial explanation. In this paper, we study data from a sample of juveniles to examine how racial differences in early police contact, and important social environments—family, school, and neighborhoods—affect later contact and arrests, controlling for self-reported delinquency. We find that early (in middle school) contact with police is an important predictor of later (high school) arrests. Also we found that, in addition to being male and living in a low-income family, children who have parents who have a history of arrest, who have experienced school disciplinary actions, who have delinquent peers, and who are in networks with deviant adults are more likely to have problems with law enforcement. These factors help to explain racial differences in police contacts and arrests.     

Power play: the use of space to control and signify power in the workplace

ABSTRACT

The findings of this article emerge from an eight-month study examining career identity practices amongst a select group of fitness professionals in the U.K. We examine how the inter-relationship between physical and social space can denote how power is acquired, displayed, and used by individuals interacting in a shared space. The findings show that power is signified through spatial practices as individuals negotiate through triadic space, creating an identity of space and place for both trainer and client that identifies power, and signifies who has power. Fitness professionals with high levels of symbolic power are able to subvert organizational spatial norms to better serve themselves and their clients, while those with lower levels of symbolic power are forced to, or choose to, negotiate or abdicate space to others. These findings are relevant to a wide range of occupations where self-employment and contract workers interact in shared space.     

Leader negative feedback-seeking and leader effectiveness in leader-subordinate relationships: The paradoxical role of subordinate expertise

From a motivational perspective of feedback-seeking behavior, we examined the mediating role of leaders' negative feedback-seeking from subordinates in the relationship between the quality of leader-member exchange (LMX) and subordinates' evaluation of leader effectiveness, along with the moderating role of subordinate expertise in the mediated relationship. Using 151 unique matched sets of leader and subordinate reports obtained from 5 large Korean companies, we found that the positive relationship between LMX and leader effectiveness was mediated by leaders' negative feedback-seeking. Additionally, the positive relationship between LMX and leader negative feedback-seeking was stronger when perceived subordinate expertise was lower. Lastly, the indirect effect of LMX on leader effectiveness through leader negative feedback-seeking was stronger when perceived subordinate expertise was lower. These findings were obtained after controlling for leaders' power distance and goal orientations that might influence their motives to seek or avoid feedback. Theoretical and practical implications are discussed.     

Total and forcing total edge-to-vertex monophonic number of a graph

For a connected graph \(G = \left( V,E\right) \), a set \(S\subseteq E(G)\) is called a total edge-to-vertex monophonic set of a connected graph G if the subgraph induced by S has no isolated edges. The total edge-to-vertex monophonic number \(m_{tev}(G)\) of G is the minimum cardinality of its total edge-to-vertex monophonic set of G. The total edge-to-vertex monophonic number of certain classes of graphs is determined and some of its general properties are studied. Connected graphs of size \(q \ge 3 \) with total edge-to-vertex monophonic number q is characterized. It is shown that for positive integers \(r_{m},d_{m}\) and \(l\ge 4\) with \(r_{m}< d_{m} \le 2 r_{m}\), there exists a connected graph G with \(\textit{rad}_ {m} G = r_{m}\), \(\textit{diam}_ {m} G = d_{m}\) and \(m_{tev}(G) = l\) and also shown that for every integers a and b with \(2 \le a \le b\), there exists a connected graph G such that \( m_{ev}\left( G\right) = b\) and \(m_{tev}(G) = a + b\). A forcing subset for S of minimum cardinality is a minimum forcing subset of S. The forcing total edge-to-vertex monophonic number of S, denoted by \(f_{tev}(S)\) is the cardinality of a minimum forcing subset of S. The forcing total edge-to-vertex monophonic number of G, denoted by \(f_{tev}(G) = \textit{min}\{f_{tev}(S)\}\), where the minimum is taken over all total edge-to-vertex monophonic set S in G. The forcing total edge-to-vertex monophonic number of certain classes of graphs are determined and some of its general properties are studied. It is shown that for every integers a and b with \(0 \le a \le b\) and \(b \ge 2\), there exists a connected graph G such that \(f_{tev}(G) = a\) and \( m _{tev}(G) = b\), where \( f _{tev}(G)\) is the forcing total edge-to-vertex monophonic number of G.     

Orphanhood and School Attendance in Nigeria: Do Gender and Household Income Matter?

Using the 2010 Nigeria Education Data Survey, this research examines the interaction of paternal and maternal/double orphanhood with gender and household income on school attendance; we ascertain whether the relationship varies by age and urban-rural residence. The research employs an economic explanation and the sociocultural construction of the gender division of labor in sub-Saharan Africa as theoretical frameworks. Findings show that the combination of being a maternal/double orphan and being female or living in a poor household leads to the lowest probability of attending school. The results also indicate that female maternal/double orphans who live in rural areas and whose age is eleven or older have the lowest probability of attending school. Both results are statistically significant. The findings support the economic explanation and the theory of sociocultural construction of the gender division of labor. Future policies should focus on subsidizing the costs of schooling for orphans.     

The Effects of Briefly Interrupting Marital Conflict

This study examined couples’ (N = 94) behavior resulting from two proximal change interventions. One was a spousal “compliments intervention” to increase positivity, and the other was a “criticize intervention” to increase negativity. Participants were randomly assigned to one of the two intervention conditions or a control group. There was no main effect in affect from the pretest conflict discussion to the posttest conflict discussion between the interventions or control group. However, a manipulation check on how couples acted during either intervention produced a significant interaction effect. Pretest affect during conflict and marital satisfaction significantly predicted couples’ construal of the intervention. Professionals may need to monitor how couples use specific interventions and direct the processes how the intervention is construed by the couple.     

Class participation as a pedagogical tool in social work education

Class participation is an essential part of the social work pedagogy. However, active student engagement in classes is inconsistent and varies based on factors such as social backgrounds, educational background, and individual characteristics. Instructors often evaluate participation based on frequency of verbal contributions. Evaluation criteria are often unarticulated or difficult to measure, presenting numerous challenges for instructors and students alike. A model of reflective self-assessment of participation by students, paired with timely instructor feedback is put forth in this paper to mitigate these concerns. The steps in this model include initial self-assessment, goal setting, midterm review, and a final review. The process of continuous self-evaluation and problem-solving is discussed as strategies that aid the process of class participation. Three instructor touch points are suggested: at the goal-setting stage, the midterm review, and the final grade. Throughout the paper, connections to social work practice and social work pedagogy are highlighted. This model has yet to be implemented in a social work school’s curriculum. Challenges in the implementation and resolution of those challenges are also presented. This model suggests ways to enhance opportunities for student engagement and integration into graduate programs, in addition to fostering valuable skills for future practice in the field.