Improving the availability of mutual exclusion Systems on Incomplete Networks

We model a distributed system by a graph G=(V, E), where V represents the set of processes and E the set of bidirectional communication links between two processes. G may not be complete. A popular (distributed) mutual exclusion algorithm on G uses a coterie C(⊆2v), which is a nonempty set of nonempty subsets of V (called quorums) such that, for any two quorums P, Q ∈ C, 1) P∩Q ≠φ and 2) P￠Q hold. The availability is the probability that the algorithm tolerates process and/or link failures, given the probabilities that a process and a link, respectively, are operational. The availability depends on the coterie used in the algorithm. This paper proposes a method to improve the availability by transforming a given coterie

More than Money: The potential of cross-sector relationships

Collaboration and co-funding between foundations has seen strong and consistent development. However, less has been done to explore and document the opportunities that collaboration across sectors between foundations, public and private sector funders may provide. 'More Than Money' provides a valuable insight into what it means for funders from different sectors to work collaboratively. Examples include the Pears Foundation working with the Department for Children, Schools and Families to turn a school linking project from a small pilot to a national project, or the development of the Evaluation Support Scotland project which began through informal discussions between a small group of funders from the statutory and voluntary sector, and continued to develop through funding from the Scottish Executive.We hope that this publication will help inform and encourage funders from all sectors as they continue to explore the exciting opportunities that cross sector collaboration can offer

Localized and Incomplete Mutual Insurance

The practice of mutual insurance is conditioned by two types of transaction costs: "association" costs in establishing links with insurance partners and "extraction" costs in using these links to implement insurance transfers. Data on insurance-motivated water exchanges among households along two irrigation canals in Pakistan show that households exchange bilaterally with neighbors and family members but the majority exchange with members of tightly knit clusters. We, therefore, develop a model that endogenizes both cluster formation and the quality of insurance in the chosen cluster as a function of the relative importance of association and extraction costs. Full insurance at the community level, the object of most empirical tests of mutual insurance, is seen to be an extreme case. It is consequently not surprising that tests of the hypothesis of full risk pooling at the community level have led to rejection. The Pakistan data support the proposition that the configuration of insurance clusters and the intensity of exchanges within clusters vary with association and extraction costs. These costs are affected by kinship, distance to neighbors, and exposure to risk. Households with larger kinship groups, closer neighbors, and greater risk exposure insure through larger clusters and more intensive exchange.mutual insurance, transaction costs, clusters, Risk and Uncertainty,

Place-based approaches to child and family services

This paper synthesizes the conceptual and empirical literature on place-based approaches to meeting the needs of young children and their families. A specific focus of the paper is on the potential contribution of place-based approaches to service reconfiguration and coordination. Outline The paper begins by outlining the sweeping social changes that have occurred in developed nations over the past few decades and their impact on children, families and communities. It explores the ‘joined up’ problems faced by families and communities in the contemporary world, and highlights the need to reconfigure services to support families more effectively. The paper then focuses on ‘joined up’ solutions, on what we know about how to meet the challenges posed by the complex problems that characterise our society. Next, the paper explores what a place-based approach involves, and what role it can play in supporting families with young children. The rationale underpinning place-based approaches is outlined and the evidence for the effectiveness of the approach is summarised. The paper then looks at what can be learned from efforts to implement place-based initiatives in Australia and overseas, and explores the issues that need to be addressed in implementing this strategy. The ways in which the early childhood service system might be reconfigured are also considered, and the paper ends with a consideration of the policy and implementation implications.&nbsp

Community-based health insurance and social protection policy

Of all the risks facing poor households, health risks pose the greatest threat to their lives and livelihoods. A health shock adds health expenditures to the burden of the poor precisely at the time when they can afford it the least.One of the ways that poor communities manage health risks, in combination with publicly financed health care services, are community-based health insurance schemes (CBHIs). These are small scale, voluntary health insurance programs, organized and managed in a participatory manner. They are designed to be simple and affordable, and to draw on resources of social solidarity and cohesion to overcome problems of small risk pools, moral hazard, fraud, exclusion and cost-escalation. Less than 10 percent of the informal sector population in the developing nations has health coverage from a CBHI, but the number of such schemes is growing rapidly. On average, CBHIs recover between a quarter to a half of health service costs. As a social protection device, they have been shown to be effective in reducing out-of-pocket payments of their members, and in improving access to health services. Many schemes do fail. Problems, such as weak management, poor quality government health services, and the limited resources that local population can mobilize to finance health care, can impede success.Health Economics&Finance,Health Monitoring&Evaluation,Poverty Assessment,Safety Nets and Transfers,Insurance&Risk Mitigation

Collective action and property rights for poverty reduction: A review of methods and approaches

"While much attention has been given to examining various aspects of poverty, a number of studies have shown that institutional environment in which the poor exist conditions welfare outcomes, thus highlighting the inherently crucial importance of institutions for poverty reduction. The institutions of property rights and collective action are among those identified as playing a major role in the livelihood strategies of the poor. This paper highlights ways to operationalize the conceptual framework developed by Di Gregorio and colleagues (2008), which provides an analytical tool to study poverty through the institutional lens with a special focus on collective action and property rights. By emphasizing the multidimensionality of poverty, the authors advocate the importance of applying various approaches and tools to conceptualizing and measuring it. They also emphasize the crucial role that institutions of collective action and property rights play in poverty reduction and sketch out theoretical nuances and methods of examining such institutions. In addition, power relations and political context are seen to be of outmost importance in poverty-related studies; the authors provide suggestions on how to understand and operationalize various dimensions of power and institutional environment in research. Outcomes are approached from the evaluative standpoint, which moves beyond straightforward empirical measurement of certain indicators to a comprehensive analysis that would involve a range of methods and approaches to both the definition and measurement of criteria that affect the complex reality of the poor." authors' abstractCollective action, Property rights, Poverty reduction, evaluation, Vulnerability, Power, Institutions, Wellbeing,

Analysing Regional Sustainability Through a Systemic Approach: The Lombardy Case Study

The intrinsic complexity of the sustainability concept challenges research towards more sophisticated ways to model and assess the dimensions underlying it. However, currently adopted modelling techniques and indicators frameworks are not able to give an integrated assessment through the different components of sustainability, providing incomplete visuals of the reality that they aim to catch. This paper tries to assess how the INSURE methodology can provide a contribution in the analysis of sustainability through indicator frameworks, describing its application to the Lombardy region (Italy). Developed on the course of a 6th European Framework Program – financed project to measure sustainability in the European regions, the methodology provides two distinct sustainability representations, based on a quantitative “top-down” System Dynamics model and on a qualitative “bottom-up” System Thinking approach. The models are then linked to a hierarchical indicator framework setting policy priorities. The overall objective is thus to create a set of regional indicators, adapting the models of regional sustainability to different policy agendas. The purpose of the paper is twofold: defining a new approach to sustainability appraisal, and assessing how the Region is holistically behaving towards sustainable development. Starting from a basis analysis of the main shortcomings highlighted by the use of most adopted methodologies, the paper will verify the contribution given by the INSURE methodology to research in the fields of modelling and indicators approaches, providing insights over methodological adjustments and the results obtained from the application to Lombardy. The conclusions will show how the methodology has tried to overcome identified constraints in current models, like the strong dependence on existing datasets of the obtained representations, the under-coverage of “immaterial factors” role and the scarce integration between sustainability dimensions.ustainable Development, Regional Economics, Econometric and Input Output Models, Development Planning and Policy, Regional Analyses

Informal Insurance in the Presence of Poverty Traps: Evidence from Southern Ethiopia

Fieldwork for this paper was conducted under the Pastoral Risk Management (PARIMA) project of the Global Livestock Collaborative Research Support Program (GL CRSP), funded by the Office of Agriculture and Food Security, Global Bureau, USAID, under grant number DAN-1328-G-00-0046-00, and analysis was underwritten by the USAID SAGA cooperative agreement, grant number HFM-A-00-01-00132-00. Financial support was also provided by the Social Science Research Council's Program in Applied Economics on Risk and Development (through a grant from the John D. and Catherine T. MacArthur Foundation), The Pew Charitable Trusts (through the Christian Scholars Program of the University of Notre Dame), the Fundação para a Ciência e Tecnologia (Portugal), and the Graduate School of Cornell University. Thanks are due to ILRI - Ethiopia for their hospitality and support and to Action for Development (Yabello) for logistical support. We thank Getachew Gebru and our field assistants, Ahmed Ibrahim and Mohammed Ibrahim, for their invaluable assistance in data collection. This is a much revised version of an earlier paper that circulated under the title: "Safety nets or social insurance in the presence of poverty traps? Evidence from southern Ethiopia". We thank Michael Carter, Stefan Dercon, Andrew Foster, Vivian Hoffman, Dhushyanth Raju, Steve Younger and participants at various conferences and seminars for comments that greatly improved this paper. The views expressed here are those of the authors and do not represent any official agency. Any remaining errors are our own.risk, informal insurance, social networks, poverty traps, Ethiopia, Risk and Uncertainty, Z13, I3, O13,

ORLease: Optimistically Replicated Lease Using Lease Version Vector For Higher Replica Consistency in Optimistic Replication Systems

There is a tradeoff between the availability and consistency properties of any distributed replication system. Optimistic replication favors high availability over strong consistency so that the replication system can support disconnected replicas as well as high network latency between replicas. Optimistic replication improves the availability of these systems by allowing data updates to be committed at their originating replicas first before they are asynchronously replicated out and committed later at the rest of the replicas. This leads the whole system to suffer from a relaxed data consistency. This is due to the lack of any locking mechanism to synchronize access to the replicated data resources in order to mutually exclude one another. When consistency is relaxed, there is a potential of reading from stale data as well as introducing data conflicts due to the concurrent data updates that might have been introduced at different replicas. These issues could be ameliorated if the optimistic replication system is aggressively propagating the data updates at times of good network connectivity between replicas. However, aggressive propagation for data updates does not scale well in write intensive environments and leads to communication overhead in order to keep all replicas in sync. In pursuance of a solution to mitigate the relaxed consistency drawback, a new technique has been developed that improves the consistency of optimistic replication systems without sacrificing its availability and with minimal communication overhead. This new methodology is based on applying the concurrency control technique of leasing in an optimistic way. The optimistic lease technique is built on top of a replication framework that prioritizes metadata replication over data replication. The framework treats the lease requests as replication metadata updates and replicates them aggressively in order to optimistically acquire leases on replicated data resources. The technique is demonstrating a best effort semi-locking semantics that improves the overall system consistency while avoiding any locking issues that could arise in optimistic replication systems