"Voluntarily Separable Prisoner's Dilemma with Reference Letters"

We consider voluntarily separable repeated Prisoner's Dilemma in which a pair of players meet randomly and repeatedly play Prisoner's Dilemma only by mutual agreement. Fujiwara-Greve and Okuno-Fujiwara (2007) consider the case that once a partnership is dissolved there is no information flow to other partnerships. We consider the case that players can issue a reference letter to the partner if they entered cooperation periods, but the content of a letter is not verifiable. We show that the sheer existence of a letter shortens the trust-building periods of new matches and thus improves efficiency in equilibrium.

Multigrade teaching in primary schools in Nepal : practice and training

Abstract:\ud One or the most significant unsolved issues in achieving Education for All is increasing the quality of education, especially among the most disadvantaged groups. In remote areas, where many of these groups live, primary schools are often organised as multigrade schools. In these schools. teachers are simultaneously responsible for two or more grades during one lesson period. However, multigrade teaching is often overlooked by both policy makers and researchers. Multigrade teachers are unsupported because mono grade teaching predominates. There is a very limited corpus of research on multigrade schools or multigrade teaching. This study aims to draw the attention of both policy makers and researchers to multigrade teaching in the context of Nepal. The research is framed by five research questions: (l) What arc the contemporary and historical system characteristics of multigrade teaching? (2) What are the characteristics of multigrade primary schools? (3) What are the practices of multigrade teaching? (4) What kind of models of im10vation and change best explain current teacher training? (5) Does current training address the problems of multigrade classrooms and improve knowledge, competence and performance of teachers? The study relies on needs-based (i. e. context and input), process and output evaluations of multigrade teacher training, conducted during twenty months of fieldwork. The main sources of evidence were observations. interviews, questionnaires, documentary analysis and focus group discussions. It can be assumed that multigrade schools are prevalent in Nepal. Although no clearly stated policies on multigrade teaching have been established, special in-service training for multigrade teaching is conducted. The practice of multigrade teaching in classrooms is diverse. Detailed observation identifies five different patterns of multigrade class organisation. This typology serves as a tool for both policy makers and researchers for understanding effective practice in the classroom. The evaluations trace the process of teacher training from the central to resource centre level, and eventually to the classrooms. Current training is inspired by diffusion-oriented models of innovation and change. While trainees gain knowledge and competence in 'practice teaching' during the training course, its final impact of the course on teacher performance in the classrooms remains modest. Problems in the training process are identified and recommendations for future improvements formulated

Prolonged maturation of prefrontal white matter in chimpanzees

Delayed maturation in the prefrontal cortex, a brain region associated with complex cognitive processing, has been proposed to be specific to humans. However, we found, using a longitudinal design, that prefrontal white matter volume in chimpanzees increased gradually with age, and the increase appears to continue beyond the onset of puberty, as in humans. This provides the first evidence for a prolonged period of prefrontal connection elaboration in great apes