Infinite Volume Limit for Correlation functions in the Dipole Gas

We study a classical lattice dipole gas with low activity in dimension $d \geq 3$. We investigate long distance properties by a renormalization group analysis. We prove that various correlation functions have an infinite volume limit. We also get estimates on the decay of correlation functions.Comment: 34 pages. Some additions, reorganizatio

Increasing public expenditure efficiency in oil-rich economies : a proposal

This paper proposes that, to increase the efficiency of public spending in oil-rich economies, some or all of the oil revenues be transferred to citizens, and fiscal instruments such as taxation be used to finance public expenditures. The authors develop the case as follows. First, they confirm the well-known result that public-expenditure efficiency is lower in oil-rich countries compared with other developing countries. Second, they show that this efficiency gap is associated with differences in accountability to citizens of government's spending decisions. They find that various measures of accountability are systematically weaker in oil-rich countries. They attribute this difference to the fact that oil revenues typically accrue directly to the government, unlike tax revenues, which pass through the hands of citizens. Third, they show that, controlling for a number of factors, accountability is stronger in countries that rely more on direct taxation to finance public spending. They conclude that accountability, and hence public expenditure efficiency, can be increased by transferring oil revenues to citizens and then taxing them to finance public spending. The paper reviews existing schemes that redistribute oil revenues to the population, such as the Alaska Citizen Fund, to assess the feasibility of a modest proposal in African countries. The authors conclude that, while it may be difficult to implement such a proposal in existing oil producers, there is scope for introducing it in some of Africa's new oil producers.Subnational Economic Development,National Governance,Public Sector Economics,Public Sector Expenditure Policy,DebtMarkets

Expanding taxable capacity and reaching revenue potential : cross-country analysis

An effective tax system is fundamental for successful country development. The first step to understand public revenue systems is to establish some commonly agreed performance measurements and benchmarks. This paper employs a cross-country study to estimate tax capacity from a sample of 104 countries during 1994-2003. The estimation results are then used as benchmarks to compare taxable capacity and tax effort in different countries. Taxable capacity refersto the predicted tax-gross domestic product ratio that can be estimated with the regression, taking into account a country's specific economic, demographic, and institutional features. Tax effort is defined as an index of the ratio between the share of the actual tax collection in gross domestic product and the predicted taxable capacity. The authors classify countries into four distinct groups by their level of actual tax collection and attained tax effort. This classification is based on the benchmark of the global average of tax collection and a tax effort index of 1 (when tax collection is exactly the same as the estimated taxable capacity). The analysis provides guidance for countries with various levels of tax collection and tax effort.Taxation&Subsidies,Debt Markets,Public Sector Economics&Finance,Emerging Markets,Economic Theory&Research

A diagnostic framework for assessing public investment management

This paper provides a pragmatic and objective diagnostic approach to the assessment of public investment management systems for governments. Since weaknesses in public investment management can negate the core argument that additional fiscal space allocated to public investments could enhance future economic prospects, attention to the processes that govern public investment selection and management is critical. The paper begins with a description of eight key"must-have"features of a well-functioning public investment system: (1) investment guidance, project development, and preliminary screening; (2) formal project appraisal; (3) independent review of appraisal; (4) project selection and budgeting; (5) project implementation; (6) project adjustment; (7) facility operation; and (8) project evaluation. The emphasis is placed on the basic processes and controls (linked at appropriate stages to broader budget processes) that are likely to yield the greatest assurance of efficiency in public investment decisions. The approach does not seek to identify best practice, but rather to identify the"must have"institutional features that would address major risks and provide an effective systemic process for managing public investments. The authors also develop a diagnostic framework to assess the main stages of the public investment management cycle. In principle, the identification of core weaknesses will allow reforms to focus scarce managerial and technical resources where they will yield the greatest impact. In addition, the framework is intended to motivate governments to undertake periodic self-assessments of their public investment systems and design reforms to enhance the productivity of public investment.Investment and Investment Climate,Debt Markets,Public Sector Expenditure Policy,Housing&Human Habitats,Bankruptcy and Resolution of Financial Distress

ON THE SINGULAR INTEGRAL EQUATIONS WITH CARLEMAN SHIFT IN THE CASE OF THE VANISHING COEFFICIENT

Joint Research on Environmental Science and Technology for the Eart

Political economy of the petroleum sector in Nigeria

The relatively slow pace of Nigeria's development has often been attributed to the phenomenon of the resource curse whereby the nature of the state as a"rentier"dilutes accountability for development and political actors are able to manipulate institutions to sustain poor governance. The impact of the political elite's resource-control and allocation of revenues on core democratic mechanisms is central to understand the obstacles to development and governance failure. Given that problems of petroleum sector governance are extremely entrenched in Nigeria, the key question is whether and how it is possible to get out of a poor equilibrium after fifty years of oil production. This paper uses a political economy perspective to analyze the governance weaknesses along the petroleum sector value chain and attempts to establish the links between challenges in sector regulation and the following major political and economic attributes: (i) strong executive control on petroleum governance in a political environment of weak checks and balances; (ii) regulatory and operating roles bundled into one institution, thereby creating conflict of interest; and (iii) manipulation of elections and political appointments. The restoration of democratic government has helped improve transparency and management of oil revenue and reforms at the federal level and proposed reforms of the petroleum sector hold much promise. At the same time, the judiciary has started to restore confidence that it will serve as a check and balance on the executive and the electoral process. Yet, these reforms are fragile and need to be deepened and institutionalized. They must be addressed not as purely technocratic matters but as issues of political economy and vested interests that must, through regulation and reform, be aligned with the public interest and a vision of Nigerian development.National Governance,Environmental Economics&Policies,Oil Refining&Gas Industry,Energy Production and Transportation,Public Sector Corruption&Anticorruption Measures