Homotopy (Pre-)Derivators of Cofibration Categories and Quasi-Categories

We prove that the homotopy prederivator of a cofibration category is equivalent to the homotopy prederivator of its associated quasi-category of frames, as introduced by Szumi\l{}o. We use this comparison result to deduce various abstract properties of the obtained prederivators.Comment: Final version, incorporating suggestions by referee. Accepted for publication in Algebraic & Geometric Topolog

Spurred Emulation: The EU and Regional Integration in Mercosur and SADC

This paper addresses the EU’s influence on the design of market-building objectives and dispute settlement mechanisms in Mercosur and SADC over time. It argues that such influence has had an independent effect on the evolution of regional institutional design that is not reducible to mere functional dynamics, which dominant explanations emphasize. Instead, it suggests that EU influence is best conceived as a process of spurred emulation, according to which major political or economic crises in the regions have led to the increasing emulation of EU arrangements, spurred by the EU’s active involvement in the process. This has, however, neither led to a wholesale copying of EU institutional models nor to the adoption of EU practices, but EU templates have regularly been adapted to fit with policy-makers’ normative convictions, especially their continuing concerns about national sovereignty

On the topology of contours of d-dimensional functions

A new algorithm to construct contour trees is introduced which improves the runtime of known approaches. It also generates additional topological information about the data which can be used to compute the Betti numbers for all possible level sets

The European Union: A Model Under Pressure

Following its establishment in 1952, both the European Coal and Steel Community and its successor, the European Union, have served as models for other regional organisations. Yet, recent crises of the European Union - including of migration, the common currency, and of Brexit - call into question the continued viability of this status. While these crises have tainted the European Union's success, predictions of its irrelevance and demise are nevertheless premature. European Union-type institutions are becoming more widespread in other parts of the world, including authoritative dispute settlement mechanisms, general secretariats with agenda-setting power, and parliamentary assemblies. These developments are due, in part, to the European Union's success as well as to its active promotion of regional integration in other parts of the world. The European Union actively promotes regionalism through financial and technical assistance as well as via the negotiation of interregional agreements. Nevertheless, European Union-type institutions seldom generate comparably positive outcomes to those in Europe itself because of other regions' greater concerns about national sovereignty, as well as different economic, political, and social contexts. Recent crises in the European Union have tainted outsiders' perceptions of it as a model of specific policy regimes; yet, the most fundamental problem has crystallised in Brexit, which expresses principled opposition to the very idea of regional cooperation. Nevertheless, the notion that regional cooperation can help nation states to secure peace and enhance economic prosperity continues to be most prominently embodied by the European Union - remaining an attractive one in a world in which conflict and poverty are still pervasive. Policymakers in Europe should realise that the attractiveness of the European Union model of regional economic integration is an important form of soft power, one that they should be ready to harness. At the same time, this appeal's endurance depends primarily on the European Union's ability to continue solving internal problems and coping with crises - where the largest threats to its positive image now come from

The Rising Authority of International Organisations

International organisations have recently come under pressure. Brexit, the election of Donald Trump, and the rise of China appear to all indicate the same thing: established international organisations are losing authority. In reality, however, the formal authority of international organisations has grown significantly in recent decades. International organisations have become more authoritative over the past few decades – that is, they are now less dependent on control by individual member states. The growing authority of international organisations is reflected in the increasing extent to which national governments (a) set aside their vetoes by endorsing majoritarian forms of decision-making (pooling) and (b) empower independent institutions to act on their behalf (delegation). This rise in international authority involves trade-offs, as pooling and delegation seldom go together. In task-specific organisations, pooling is widespread, whereas delegation is limited; in general-purpose organisations, the opposite is the case. The reasons for the rise in international authority are threefold: (i) the functional quest for effective cooperation, (ii) increasing political demands for participation by non-governmental actors, and (iii) the diffusion of authoritative institutional templates amongst international organisations. These forces are likely to continue pushing towards greater international authority in the future. Stronger international organisations also invite contestation, which induces certain governments to devise strategies to circumvent those organisations they perceive to be overly authoritative. These trends could potentially weaken existing international organisations. For much of the post-war period, international organisations have largely operated out of the limelight; however, this is changing as their authority increases. Policymakers should realise that international organisations’ growing authority may fuel a political backlash that could lead to stagnation or even backsliding. While there are compelling reasons for deeper international collaboration in an interdependent world, political contestation has the potential to override them

Frame diffusion and institutional choice in regional economic cooperation

Why have many regional organizations adopted common markets and customs unions? This article proposes a cognitive diffusion mechanism - termed frame diffusion - to explain convergent institutional choices across structurally diverse settings. Using Strang and Meyer's (1993) notion of 'theorization' to combine foundational work on framing with the literature on diffusion, I argue that processes of theorization transform the experience of successful institutional innovators into abstract cognitive schemas, which link a particular understanding of a cooperation problem to specific institutional solutions. As policymakers in other contexts encounter similar cooperation problems, they adopt framed institutional solutions, which results in institutional convergence at the macro level. I further suggest that this process of frame diffusion is conditional on ideational affinities in social purpose between the innovating organization and other regional organizations. Where other organizations pursue a distinct social purpose, policymakers rely on alternative frames and thereby cement institutional variation. After developing this argument theoretically, I illustrate it in an exploratory comparison of institutional choice in three most different regional organizations: Association of Southeast Asian Nations, Common Market of the South, and the Southern African Development Community. The argument points to significant 'blind spots' and conceptual complementarity between prominent mechanisms of diffusion

G-Global Homotopy Theory and Algebraic K-Theory

We develop the foundations of $G$-global homotopy theory as a synthesis of classical equivariant homotopy theory on the one hand and global homotopy theory in the sense of Schwede on the other hand. Using this framework, we then introduce the $G$-global algebraic $K$-theory of small symmetric monoidal categories with $G$-action, unifying $G$-equivariant algebraic $K$-theory, as considered for example by Shimakawa, and Schwede's global algebraic $K$-theory. As an application of the theory, we prove that the $G$-global algebraic $K$-theory functor exhibits the category of small symmetric monoidal categories with $G$-action as a model of connective $G$-global stable homotopy theory, generalizing and strengthening a classical non-equivariant result due to Thomason. This in particular allows us to deduce the corresponding statements for global and equivariant algebraic $K$-theory.Comment: Several minor corrections and changes to exposition, some additional material; v + 236 page