Fractional Zero Forcing via Three-color Forcing Games

An $r$-fold analogue of the positive semidefinite zero forcing process that is carried out on the $r$-blowup of a graph is introduced and used to define the fractional positive semidefinite forcing number. Properties of the graph blowup when colored with a fractional positive semidefinite forcing set are examined and used to define a three-color forcing game that directly computes the fractional positive semidefinite forcing number of a graph. We develop a fractional parameter based on the standard zero forcing process and it is shown that this parameter is exactly the skew zero forcing number with a three-color approach. This approach and an algorithm are used to characterize graphs whose skew zero forcing number equals zero.Comment: 24 page

Imperfect Contract Enforcement

We model imperfect contract enforcement when repudiators and their victims default to spot trading. The interaction between the contract and spot markets under improved enforcement can exacerbate repudiation and reduce contract execution, harming all traders. Improved contract execution benefits traders on the excess side of the spot market by attracting potential counter-parties, but harms them by impeding their exit from contracts found to be unfavorable. Multiple equilibria and multiple optima are possible, with anarchy a local optimum, perfect enforcement a local minimum and imperfect enforcement a global optimum. LDCs exhibit parameter combinations such that imperfect enforcement is optimal from their side of international markets. The model thus rationalizes the internationally varying patterns of imperfect enforceability observable in survey data.

Trade Implies Law: The Power of the Weak

Without the rule of law, traders who incur trading costs can be held up by counter-parties who are stronger in anarchic bargaining. The favourable terms which the latter extract can overcrowd that side of the market, dissipating the benefits. We establish plausible necessary and sufficient conditions for a move from anarchy toward the rule of law to benefit all traders. The rule of law might be delayed, not only by the difficulties of setting up legal institutions, but by monopolistic traders that have meantime emerged to address the inefficiencies of anarchic trade. These monopolistic traders must also guarantee atomistic traders against holdup.

Globalization and Financial Regulation

There has been no shortage of villains in the financial crisis which began in Asia and has now encompassed all major emerging markets: bankers regulators hedge funds and the IMF have all been excoriated for incompetence and immorality. This paper argues that the problems which have emerged from the crisis are structural i.e. they arise from the very nature of financial activity. While the structural problems have been present from the beginnings of finance the advance of technology and of globalization has so exacerbated the problems as to undermine the foundations of the international market order. To highlight the structural nature of the problems this paper will eschew the search for villains and examine the theoretical basis for the globalization of financial markets - the major direction of their recent evolution. Economic theory identifies major difficulties in the presumption that this drive will lead to socially desirable outcomes. The financial crisis can be understood as the exacerbation of these difficulties by globalization and the advance of information technology

The East Asian Financial Crisis

After describing the major events in the regional financial crisis I shall link them to structural problems in Asian finance. These structural problems arise from institutional limitations grounded in the culture and political economy of East Asia. The "East Asian Model" of political economy was successful in manufacturing giving rise to triumphant rhetoric on Asian values from Asian leaders last year. I shall attempt to identify why the "East Asian Model" failed in finance. I conclude with a discussion of the dangers & opportunities created by the regional financial crisis

Veteran K-6 Public School Teachers: Remaining Committed and Staying Engaged in Their Careers

This phenomenological qualitative study involved 15 veteran K-6 public school teachers – each having taught a minimum of 24 years - from several districts in Southern California. It identified and examined what factors influenced the ongoing commitment and engagement of these teachers over the course of their careers. Factors mirrored the study’s theoretical framework and included: 1) the teacher’s challenges, 2) the teacher’s personal characteristics or attributes, and 3) the teacher’s professional life phases. A majority of the teachers interviewed spoke to the escalation of the environmental challenges they confronted while on the job, such as, student behavior, administrative and parental support, educational reform, work load, and instructional time constraints as well as individual factors, such as, family issues and personality. In particular, the increased aggressive misbehavior of some students along with an all-too-common lack of support from both parents and administrators left these teachers feeling disrespected, isolated, and even burnt-out at times. However, the study’s findings pointed to the affirmative power of the teachers’ personal characteristics – specifically, their passion for teaching and their students along with the teachers’ resilience – in helping them to combat the trying environmental and individual challenges they faced during the various professional life phases of their careers, and remain committed and engaged. Moreover, the study’s findings suggest that veteran teachers could benefit from recognition, growth, variety and interaction with colleagues in order to have a meaningful longevity in their careers as well as more robust support from both site and district administrators. The findings also recommend that teacher educators introduce their pre-service and beginning teachers to what it takes emotionally to stay committed and engaged in the profession in meaningful ways, thereby, giving these new teachers a deeper foundation of what being an effective and fulfilled teacher really entails

The effects of thalamic, frontal cortical and hippocampal formation lesions on a delayed nonmatching to sample task

Two areas of the brain have been implicated in global amnesia: the medial temporal lobe and the midline diencephalon (Squire and Zola-Morgan; Victor, Adams, and Collins, 1989). A third area of the brain, the prefrontal cortex, has more recently been included as a memory related area (Fuster, 1989). The purpose of the study reported here was to further examine the neurological basis of the delayed nonmatching to sample place cue task (DNMTS-PC) deficit by comparing lesions in each of the three major areas attributed to memory processes. Patterns of impairments on the DNMTS-PC were further understood by manipulating retention and inter-trial intervals and by extensive pretreatment training. The effects of radio frequency lesions of the L-IML were compared to lesions in the MW and the dentate nucleus of the hippocampal formation (HP). DNMTS was measured with three retention intervals within session (0.4, 1.6, 6.4 s). Inter-trial interval was varied between sessions (0.8, 3.2, 12.8 s). L-IML, MW, and HP groups were significantly impaired on the initial 1008 trials. HP animals recovered their performance within the first 432 trials of post-surgical training. Following recovery of performance HP animals were not significantly impaired for the duration of post-surgical training. L-IML and MW animals continued to be impaired across different inter-trial interval manipulations. L-IML lesions result in substantial impairment on the DNMTS-PC task. MW lesions also produced substantial impairment on the DNMTS-PC task. Although the effects of the L-IML lesion on the DNMTS-PC task can be accounted for by the MW lesion, when compared across studies MW lesions produced more selective impairments on working memory tasks than did L-IML lesions