Indicators of Economic Crises : A Data-Driven Clustering Approach

The determination of reliable early-warning indicators of economic crises is a hot topic in economic sciences. Pinning down recurring patterns or combinations of macroeconomic indicators is indispensable for adequate policy adjustments to prevent a looming crisis. We investigate the ability of several macroeconomic variables telling crisis countries apart from non-crisis economies. We introduce a selfcalibrated clustering-algorithm, which accounts for both similarity and dissimilarity in macroeconomic fundamentals across countries. Furthermore, imposing a desired community structure, we allow the data to decide by itself, which combination of indicators would have most accurately foreseen the exogeneously defined network topology. We quantitatively evaluate the degree of matching between the data-generated clustering and the desired community-structure.info:eu-repo/semantics/publishedVersio

Who Replaces Whom? Local versus Non-local Replacement in Social and Evolutionary Dynamics

In this paper, we inspect well-known population genetics and social dynamics models. In these models, interacting individuals, while participating in a self-organizing process, give rise to the emergence of complex behaviors and patterns. While one main focus in population genetics is on the adaptive behavior of a population, social dynamics is more often concerned with the splitting of a connected array of individuals into a state of global polarization, that is, the emergence of speciation. Applying computational and mathematical tools we show that the way the mechanisms of selection, interaction and replacement are constrained and combined in the modeling have an important bearing on both adaptation and the emergence of speciation. Differently (un)constraining the mechanism of individual replacement provides the conditions required for either speciation or adaptation, since these features appear as two opposing phenomena, not achieved by one and the same model. Even though natural selection, operating as an external, environmental mechanism, is neither necessary nor sufficient for the creation of speciation, our modeling exercises highlight the important role played by natural selection in the interplay of the evolutionary and the self-organization modeling methodologies.Comment: 14 pages, 11 figure

Interlinkages and structural changes in cross-border liabilities: a network approach

We study the international interbank market through a geometrical and a topological analysis of empirical data. The geometrical analysis of the time series of cross-country liabilities shows that the systematic information of the interbank international market is contained in a space of small dimension, from which a topological characterization could be conveniently carried out. Weighted and complete networks of financial linkages across countries are developed, for which continuous clustering, degree centrality and closeness centrality are computed. The behavior of these topological coefficients reveals an important modification acting in the financial linkages in the period 1997-2011. Here we show that, besides the generalized clustering increase, there is a persistent increment in the degree of connectivity and in the closeness centrality of some countries. These countries seem to correspond to critical locations where tax policies might provide opportunities to shift debts. Such critical locations highlight the role that specific countries play in the network structure and helps to situates the turbulent period that has been characterizing the global financial system since the Summer 2007 as the counterpart of a larger structural change going on for a more than one decade.Comment: 24 pages, 11 figure

On Positional Consumption and Technological Innovation- an Agent-based Approach

Positional behavior is a source of externalities and sets limits to wellbeing. Remedies against this market failure are defended by some authors and rejected by others, while the core of the discussion rests on the benefits and costs of applying economic instruments. One of the issues discussed is the role that the competition for positional goods may have in generating technological innovation. This paper aims to contribute to the understanding of this process by analyzing an agent-based model. We observe a plausible structure of the dynamics behind the process of generation of technological innovation by positional consumption and obtain results on the influence of some key factors on the pace of innovation, particularly those of income inequality, the Hirsch conjecture of relative increase of positional consumption with affluence, and consumer network and social neighborhood sizes.Positional consumption, innovation, agent-based models, Robert Frank

The Labour Market on the Hypercube

Positions offered on a labour market and workers preferences are here described by bit-strings representing individual traits. We study the co-evolution of workers and firm preferences modeled by such traits. Individual ”size-like” properties are controlled by binary encounters which outcome depends upon a recognition process. Depending upon the parameter set-up, mutual selection of workers and positions results in different types of attractors, either an exclusive niches regime or a competition regime.

Tribes under Threat – The Collective Behavior of Firms During the Stock Market Crisis

Due to their unpredictable behavior, stock markets are examples of complex systems. Yet, the dominant analysis of these markets as- sumes simple stochastic variations, eventually tainted by short-lived memory. This paper proposes an alternative strategy, based on a stochastic geometry de¯ning a robust index of the structural dynamics of the markets and based on notions of topology de¯ning a new coef- ficient that identifies the structural changes occurring on the S&P500 set of stocks. The results demonstrate the consistency of the random hypothesis as applied to normal periods but they also show its in- adequacy as to the analysis of periods of turbulence, for which the emergence of collective behavior of sectoral clusters of firms is mea- sured. This behavior is identified as a meta-routine.