The Permissible Reach of National Environmental Policies

Trading nations exchange tariff concessions in the context of trade liberalizing rounds. Tariffs, nonetheless, are not the only instrument affecting the value of a concession. Domestic instruments affect it as well, but public order is not negotiable, and, consequently, is not scheduled. Public order is unilaterally defined, but must respect the default rules concerning allocation of jurisdiction which are common to all WTO Members and bind them by virtue of their appurtenance to the international community. In this paper, we focus on the interaction between trade and environment. The purpose of this study is to highlight how these rules and the GATT/WTO jointly determine the scope for unilateral environmental policies for WTO Members. In the study we examine the relevant multilateral framework dealing with this issue, as well as the relevant GATT and WTO case-law. We also briefly present the jurisdictional default rules in Public International Law. As a means of focusing the discussion, we consider a series of scenarios, partly building on factual aspects of cases that have already been brought before the WTO. These scenarios are intended to isolate issues of specific interest from a policy point of view. For each scenario we then seek to determine what would the outcome be, in case WTO adjudicating bodies were to explicitly take account of the default rules concerning allocation of jurisdiction, something which has not been done to date. Our main conclusions are two-fold: on occasion, the outcome would be different, had WTO panels observed the default rules concerning allocation of jurisdiction; more generally, the default rules can help us understand the limits of some key obligations assumed under the WTO. Crucially, absent recourse to the default rules concerning allocation of jurisdiction, one risks understanding non-discrimination (the key GATT-obligation) as an instrument aimed to harmonize conditions of competition across markets, and not within markets, as the intent of negotiators has always been.Trade and Environment; WTO

A Survey of the Literature on the WTO Dispute Settlement System

This paper surveys the law and economics literature on WTO dispute settlement. As a background, we first briefly lay out main features of the legal framework, and discuss possible roles of a dispute settlement mechanism. We then discuss the two main themes in the empirical literature on dispute settlement: (i) the determinants of participation by members as complainants, respondents and third parties; and (ii) the role of the DS system for the settling of disputes. The paper finally points to a number of areas that are in need of further research.WTO; Dispute Settlement; DSU

The WTO Dispute Settlement System 1995-2010: Some Descriptive Statistics

The Dispute Settlement (DS) system is a central feature of the World Trade Organization (WTO) Agreement. This compulsory and binding two-level mechanism for the adjudication of disputes between WTO Members is the most active among international courts. The functioning of the DS system has attractive research interest among both lawyers and economists. This paper reports some descriptive statistics of the working of the DS system based on the recently updated Horn and Mavroidis WTO Dispute Settlement Data Set. The data set covers all 426 WTO disputes initiated through the official filing of a Request for Consultations from January 1, 1995, until August 11, 2011, and for these disputes it includes events occurring until July 28, 2011. There are in total approximately 67 000 observations. Each dispute is followed through its legal life via the panel stage, the Appellate Body stage, through to the implementation stage. The paper provides information on fundamental aspects of the use of the DS system, such as: • How active have the different countries been as complainants and as respondents? • Which agreements and which provisions are most commonly cited? • How are the adjudicating panels composed? • How successful have the different participants been?WTO; Dispute Settlement; Developing Countries

Soft Contract Verification

Behavioral software contracts are a widely used mechanism for governing the flow of values between components. However, run-time monitoring and enforcement of contracts imposes significant overhead and delays discovery of faulty components to run-time. To overcome these issues, we present soft contract verification, which aims to statically prove either complete or partial contract correctness of components, written in an untyped, higher-order language with first-class contracts. Our approach uses higher-order symbolic execution, leveraging contracts as a source of symbolic values including unknown behavioral values, and employs an updatable heap of contract invariants to reason about flow-sensitive facts. We prove the symbolic execution soundly approximates the dynamic semantics and that verified programs can't be blamed. The approach is able to analyze first-class contracts, recursive data structures, unknown functions, and control-flow-sensitive refinements of values, which are all idiomatic in dynamic languages. It makes effective use of an off-the-shelf solver to decide problems without heavy encodings. The approach is competitive with a wide range of existing tools---including type systems, flow analyzers, and model checkers---on their own benchmarks.Comment: ICFP '14, September 1-6, 2014, Gothenburg, Swede

Size-Change Termination as a Contract

Termination is an important but undecidable program property, which has led to a large body of work on static methods for conservatively predicting or enforcing termination. One such method is the size-change termination approach of Lee, Jones, and Ben-Amram, which operates in two phases: (1) abstract programs into "size-change graphs," and (2) check these graphs for the size-change property: the existence of paths that lead to infinite decreasing sequences. We transpose these two phases with an operational semantics that accounts for the run-time enforcement of the size-change property, postponing (or entirely avoiding) program abstraction. This choice has two key consequences: (1) size-change termination can be checked at run-time and (2) termination can be rephrased as a safety property analyzed using existing methods for systematic abstraction. We formulate run-time size-change checks as contracts in the style of Findler and Felleisen. The result compliments existing contracts that enforce partial correctness specifications to obtain contracts for total correctness. Our approach combines the robustness of the size-change principle for termination with the precise information available at run-time. It has tunable overhead and can check for nontermination without the conservativeness necessary in static checking. To obtain a sound and computable termination analysis, we apply existing abstract interpretation techniques directly to the operational semantics, avoiding the need for custom abstractions for termination. The resulting analyzer is competitive with with existing, purpose-built analyzers

Mean Temperature Profiles in Turbulent Thermal Convection

To predict the mean temperature profiles in turbulent thermal convection, the thermal boundary layer (BL) equation including the effects of fluctuations has to be solved. In Shishkina et al., Phys. Rev. Lett. 114 (2015), the thermal BL equation with the fluctuations taken into account as an eddy thermal diffusivity has been solved for large Prandtl-number fluids for which the eddy thermal diffusivity and the velocity field can be approximated respectively as a cubic and a linear function of the distance from the plate. In the present work we make use of the idea of Prandtl's mixing length model and relate the eddy thermal diffusivity to the stream function. With this proposed relation, we can solve the thermal BL equation and obtain a closed-form expression for the dimensionless mean temperature profile in terms of two independent parameters for fluids with a general Prandtl number. With a proper choice of the parameters, our predictions of the temperature profiles are in excellent agreement with the results of our direct numerical simulations for a wide range of Prandtl numbers from 0.01 to 2547.9 and Rayleigh numbers from 10^7 to 10^9.Comment: 8 pages, 4 figure

Winners and Losers in the Panel Stage of the WTO Dispute Settlement System

A significant body of research has sought to examine claims that developing countries are under-represented as complainants, and/or over-represented as respondents in the WTO dispute settlement system. Most of this literature has focused on their propensity to participate, the idea being that under-representation as complainants or over representation as respondents would suggest a bias in the system. This paper provides some descriptive statistics that could shed light on a different manifestation of a “bias” against developing countries. It employs a dataset containing information on the legal claims made in each WTO dispute between 1995 and 2006, as well as a rough classification as to whether each specific claim was accepted or not by the respective panel. The data is used to compare the extent to propensity by which G2 countries, other industrialized countries, and developing countries have won the claims that they have made before panels.WTO; Dispute Settlement; Developing Countries; Winners and Losers