Generalized Points-to Graphs: A New Abstraction of Memory in the Presence of Pointers

Flow- and context-sensitive points-to analysis is difficult to scale; for top-down approaches, the problem centers on repeated analysis of the same procedure; for bottom-up approaches, the abstractions used to represent procedure summaries have not scaled while preserving precision. We propose a novel abstraction called the Generalized Points-to Graph (GPG) which views points-to relations as memory updates and generalizes them using the counts of indirection levels leaving the unknown pointees implicit. This allows us to construct GPGs as compact representations of bottom-up procedure summaries in terms of memory updates and control flow between them. Their compactness is ensured by the following optimizations: strength reduction reduces the indirection levels, redundancy elimination removes redundant memory updates and minimizes control flow (without over-approximating data dependence between memory updates), and call inlining enhances the opportunities of these optimizations. We devise novel operations and data flow analyses for these optimizations. Our quest for scalability of points-to analysis leads to the following insight: The real killer of scalability in program analysis is not the amount of data but the amount of control flow that it may be subjected to in search of precision. The effectiveness of GPGs lies in the fact that they discard as much control flow as possible without losing precision (i.e., by preserving data dependence without over-approximation). This is the reason why the GPGs are very small even for main procedures that contain the effect of the entire program. This allows our implementation to scale to 158kLoC for C programs

The present moment in quantum cosmology: challenges to the arguments for the elimination of time

Barbour, Hawking, Misner and others have argued that time cannot play an essential role in the formulation of a quantum theory of cosmology. Here we present three challenges to their arguments, taken from works and remarks by Kauffman, Markopoulou and Newman. These can be seen to be based on two principles: that every observable in a theory of cosmology should be measurable by some observer inside the universe, and all mathematical constructions necessary to the formulation of the theory should be realizable in a finite time by a computer that fits inside the universe. We also briefly discuss how a cosmological theory could be formulated so it is in agreement with these principles.Comment: This is a slightly revised version of an essay published in Time and the Instant, Robin Durie (ed.) Manchester: Clinamen Press, 200

Russia: Political and Institutional Determinants of Economic Reforms

The purpose of this study is to analyze the course, determinants and political economy of economic reforms in Russia conducted in the period 1985-2003. The year 1985 can be considered an important turning point in Soviet/Russian history, marked as it was by the election of Mikhail Gorbachev to the position of General Secretary of the Communist Party of Soviet Union (CPSU) and (de facto) leader of the USSR. This nomination brought an end to two decades of political consolidation of the communist regime connected with the name of General Secretary Leonid Brezhnev and his short living successors (Yurii Andropov and Konstantin Chernenko), often referred to ex post as 'the stagnation period' (vremya zastoya). Gorbachev initiated a series of important political and (to a lesser extent) economic reforms, which led eventually to the collapse of the communist regime and the disintegration of the Soviet empire in 1991. Thus, 1991 must be seen as another dramatic turning point in Russia's contemporary history. From the end of 1991 onwards political and economic reforms have been carried out by the new Russian state that emerged after the disintegration of the USSR. This paper aims to explain the political and institutional determinants of economic reforms in the Russian Federation. It has been carried out under the Global Research Project on 'Understanding Reforms' organized and financed by the Global Development Network (GDN)1 as one of 30 country studies covering a broad set of developing and transition economies. It presents the project's intermediate results and will be the subject of further discussion as well as analytical and editorial work in the near future. The case of Russia is very important and interesting from the point of view of GRP 'Understanding Reforms' goals and agenda, for many reasons. First, all transitions from communist regimes and centrally-planned economies to democratic capitalism represent a much more complex, complicated and difficult reform experience than policy reforms observed in developing countries, especially when they relate to just one or a few specific policy areas. Thus, learning the transition experience, particularly in its early phase, can provide an extremely valuable empirical input to 'understanding reform' and provide answers to the project's key questions: 'why reform?', 'what reform?', and 'how well did the reform perform?'economic reforms, transition, Russia, reform sequencing, political reforms, institutional reforms, political economy.

Explaining visa, asylum and immigration policy Treaty revision: insights from a revised neofunctionalist framework

This paper seeks to explain the varying, and sometimes intriguing, outcomes of the past three Treaty revision negotiations of European Union/Community visa, asylum and immigration policy. Regarding this policy area, I focus on the substantial constitutional issues of decision rules and institutional set-up. The results of the Intergovernmental Conference (IGC) negotiations leading to the Amsterdam Treaty, the Treaty of Nice and the Constitutional Treaty are subjected to causal analysis. The paper draws on a revised neofunctionalist framework and argues that five explanatory factors can account for the Treaty outcomes: (1) functional pressures; (2) the role of supranational institutions; (3) socialisation, deliberation and learning processes; (4) exogenous pressures; and (5) countervailing forces.political science; intergovernmental conferences; treaty reform; European Convention; asylum policy; immigration policy; neo-functionalism; socialization

THE URUGUAY ROUND AGREEMENT ON AGRICULTURE: AN EVALUATION

Contact for this paper: Laura Bipes/University of Minnesota/Department of Applied Economics/ 1994 Buford Avenue./ St. Paul, MN 55108 USA. From the start, agriculture played a central role in the Uruguay Round of GATT trade negotiations. The Punta del Este Declaration called for a solution to the problems facing agricultural trade through modified trade rules and an agreement to lower protection levels. It was recognized that such an improvement implied negotiations on the national farm policies as well as just trade policies. The time that it took to reach agreement reflected the political sensitivity and technical complexity of this task. The Agreement embodied in the Final Act of the Uruguay Round breaks new ground for agriculture, and takes a big step towards placing this sector of world trade under rules more consistent with those in operation in other areas. However, the degree of liberalization of markets is modest, and much remains to be done in future rounds of negotiations. The most far-reaching element in the Agreement is a change in the rules regarding market access. With very few exceptions, all participating countries have agreed to convert all existing non-tariff barriers (along with unbound tariffs) into bound duties and not to introduce new non-tariff measures. Negotiations agreed to reduce these new bound tariffs, as well as tariffs already bound earlier, according to Schedules included as a part of the Agreement. "Tariffication" will impose changes in import policies for a number of countries. Canada will replace import quotas for dairy and poultry products with tariffs, initially at a high level. The European Union will replace its variable levy with tariffs, though a maximum duty-paid price for cereals has been negotiated which puts a limit on the tariff charged. Latin American countries have generally engaged in tariffication in recent years in advance of the Uruguay Round Agreement: for these, and other countries their tariffs will now be bound. The US will forgo the use of Section 22 import quotas and the negotiation of voluntary export restraint agreements with beef suppliers, but the impact on these markets is likely to be small. Japan and Korea have been allowed to delay tariffication in the case of rice for the next few years. The Agreement provides in cases of tariffication for "minimum access opportunities", to guard against the impact of high initial tariff rates. This will open up reduced-tariff quotas for a number of products including beef, cereals and fruits and vegetables. The quotas will be expanded to about 5 percent of consumption over the 6 year period. Japan and Korea have agreed to a greater expansion of market access for rice in compensation for the delay in introducing tariffs. The ability of countries to control export subsidies in agricultural markets was one of the main issues under discussion in the negotiation. Under the Agreement, countries accept commitments on reducing expenditure on export subsidies as well on the quantity of subsidized exports. This will limit export subsidies by the EU and other countries, for such products as wheat, dairy products and beef, and should lead to firmer world market prices in these commodities. These quantities are also expressed in the Schedules which form part of the Agreement. Countries have also agreed not to apply export subsidies to commodities not subsidized in the base period. The Agreement also sets rules and commitments for domestic support policies. It defines a set of policies which are deemed to be less trade-distorting than others, and allocates them to a "green box" which is broadly immune to challenge. Other policies not sheltered in this way are subject to reduction through a limit on the total support given by domestic subsidies and administered prices. It was decided that neither the U.S. deficiency payments (under current legislation) nor the new hectarage compensation payments under the reformed Common Agricultural Policy of the EU need to be reduced. It was also agreed that subsidies that conform to the new rules are sheltered from international challenge under the GATT. Developing Countries generally face less stringent commitments, having 10 years rather than six to make the changes, and having to meet only two-thirds of the reduction targets. In addition, development policies are included broadly in the "green box". Along with the provisions on domestic and trade policies in the Agreement, participants also concluded an Agreement on Sanitary and Phytosanitary Measures (SPS Agreement). The goal was to make it easier to distinguish between genuine health and safety issues and disguised protection. The right of countries to set their own safety and health standards is reaffirmed, but with the provision that such standards should be based on scientific justification and that use be made of international standards where possible. The extent to which the Agreement will lead to greater market access, curb export subsidies and modify domestic policies in the next few years can only be determined from a detailed inspection of the Schedule of commitments made by the individual countries. Paradoxically, the immediate impact on national policies is likely in most cases to be small. Many countries have been engaged in a process of reducing government support to agriculture, and making such support more closely targetted to needs, in advance of the outcome of the Round. Policy reforms in the EU, Canada, Sweden, Australia and New Zealand, along with much of Latin America, have been strongly influenced by the negotiations in the Uruguay Round. The Agreement thus takes on the task of supporting and locking-in such reforms, and encouraging them in other countries. In some aspects the Agreement falls short of expectations (or at least initial demands). It does not constitute a major move toward free trade in agricultural products: the cost of changing the rules has been to give up some degree of liberalization. The tariffs which countries will impose in place of non-tariff barriers are in many cases so high that trade will be restricted to the agreed access quantities. Export subsidy programs will continue though at a reduced level. The major pressure to reinstrument farm policies will continue to be from domestic budget constraints. It will take further rounds of negotiations to reduce protection in agricultural markets to a level comparable to that for most manufactured products. However, with the rule changes and the new types of country commitments agreed, a much more promising basis bas been created for future negotiations.International Relations/Trade,