2,978 research outputs found

    Macroeconomic forecasting with statistically validated knowledge graphs

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    This study leverages narrative from global newspapers to construct theme-based knowledge graphs about world events, demonstrating that features extracted from such graphs improve forecasts of industrial production in three large economies compared to a number of benchmarks. Our analysis relies on a filtering methodology that extracts ā€œbackbonesā€ of statistically significant edges from large graph data sets. We find that changes in the eigenvector centrality of nodes in such backbones capture shifts in relative importance between different themes significantly better than graph similarity measures. We supplement our results with an interpretability analysis, showing that the theme categories ā€œdiseaseā€ and ā€œeconomicā€ have the strongest predictive power during the time period that we consider. Our work serves as a blueprint for the construction of parsimonious ā€“ yet informative ā€“ theme-based knowledge graphs to monitor in real time the evolution of relevant phenomena in socio-economic systems

    Computation of molecular excited states on IBM quantum computers using a discriminative variational quantum eigensolver

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    Solving for molecular excited states remains one of the key challenges of modern quantum chemistry. Traditional methods are constrained by existing computational capabilities, limiting the complexity of the molecules that can be studied or the accuracy of the results that can be obtained. Several quantum computing methods have been suggested to address this limitation. However, these typically have hardware requirements which may not be achieved in the near term. We propose a variational quantum machine learning based method to determine molecular excited states aiming at being as resilient as possible to the defects of early noisy intermediate scale quantum computers and demonstrate an implementation for H on IBM Quantum Computers. Our method uses a combination of two parametrized quantum circuits, working in tandem, combined with a variational quantum eigensolver to iteratively find the eigenstates of a molecular Hamiltonian

    Thermodynamics of Heat Shock Response

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    Production of heat shock proteins are induced when a living cell is exposed to a rise in temperature. The heat shock response of protein DnaK synthesis in E.coli for temperature shifts from temperature T to T plus 7 degrees, respectively to T minus 7 degrees is measured as function of the initial temperature T. We observe a reversed heat shock at low T. The magnitude of the shock increases when one increase the distance to the temperature T0ā‰ˆ23oT_0 \approx 23^o, thereby mimicking the non monotous stability of proteins at low temperature. Further we found that the variation of the heat shock with T quantitatively follows the thermodynamic stability of proteins with temperature. This suggest that stability related to hot as well as cold unfolding of proteins is directly implemented in the biological control of protein folding. We demonstrate that such an implementation is possible in a minimalistic chemical network.Comment: To be published in Physical Review Letter

    Political Regimes and Sovereign Credit Risk in Europe, 1750-1913

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    This article uses a new panel data set to perform a statistical analysis of political regimes and sovereign credit risk in Europe from 1750 to 1913. Old Regime polities typically suffered from fiscal fragmentation and absolutist rule. By the start of World War I, however, many such countries had centralized institutions and limited government. Panel regressions indicate that centralized and?or limited regimes were associated with significant improvements in credit risk relative to fragmented and absolutist ones. Structural break tests also reveal close relationships between major turning points in yield series and political transformations

    Tilly's Technical Accounts and Standard Stories Explored in Financial Markets:The Case of the Istanbul Stock Exchange

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    In this article, I follow the lead opened up by Tilly (1999, 2002) who was interested in people's storytelling. I do so by looking at sense-making and the legitimacy narratives of market actors in the Istanbul Stock Exchange. Tilly (2006, 2008) himself walked the narrative path and investigated Why and how people give reasons and how people attribute Credit and Blame to other's actions. These books provide insights into people's storytelling in the everyday situations of the home, courtrooms, hospitals, and so on. Nevertheless, Tilly's faith in the prevalence of technical accounts as modes of explanation in intra and inter organisational settings, and superior stories as mode of communication between expert givers and non-specialized receivers, seems to ignore informational uncertainties, intra and inter organisational hierarchies and conflicts pertinent to organisations. It is these factors that push standard stories (Tilly, 1999) into the forefront at the expense of technical stories within the story exchanges of market actors. I demonstrate this by presenting a sample of story exchanges from the Istanbul Stock Exchange under situations of informational uncertainties and organisational conflicts

    Economic precariousness: A new channel in the housing market cycle

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    Abstract: Demographic and institutional elements, as important drivers of the housing market, should not be neglected since it is not only financial and monetary elements that matter in the case of the housing market. In this context, one relationship, which still remains unclear, is the relationship between the housing and the labour markets. Some research has been undertaken to support the hypothesis that high rates of homeownership lead to high unemployment via increases in the reservation wage. However, further research is needed to address the possible implications of the institutional settings of the labour market in the dynamics of the housing market. The aim of this paper is to bring some light on the link between both markets. In particular, this contribution explains how the housing cycle could be ā€˜amplifiedā€™ via a new channel, i.e. economic precariousness, which is closely related to job insecurity. Subsequently, we provide evidence in the case of five developed economies, Ireland, the Netherlands, Spain, the United Kingdom and the United States, over the period 1985-2013.Not appicabl

    Understanding governmental activism

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    This article seeks to understand an understudied phenomenon: governmental players joining forces with non-governmental players in contentious actions against policies they want to prevent or redress. This behaviour, which we call ā€˜governmental activismā€™, problematizes important assumptions in the social movement literature on stateā€“SMO dichotomies and on seeing ā€˜the stateā€™ as a homogeneous and unified actor that solely provides the context for SMO activities. Governmental activism also problematizes assumptions on cooperation and ā€˜newā€™ modes of coordination in the governance literature. To understand governmental activism, we build on the strategic interaction perspective from social movement studies and on third-phase institutionalism from political science. In our analysis, we show the particulars of governmental activism. Our arguments are illustrated by empirical material on a case of municipal amalgamation in the Netherlands

    National protest agenda and the dimensionality of party politics: Evidence from four East-Central European democracies

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    Contemporary democracies show considerable differences in the issue composition of their protest politics, which tends to remain relatively stable over time. In countries like Germany or the Czech Republic, the vast majority of protests have been mobilised around sociocultural issues, such as human rights, peace, nuclear power or the environment, and only a tiny portion of protest has focused on economic issues. At the opposite extreme, protest in France or Poland usually has a strongly economic character and voices demands relating to material redistribution and social policy. What lies behind the cross-country differences in national protest agendas? In this article, the national protest agenda depends on what issues mainstream political parties are contesting: the content and strength of the master-issue dimension. In reference to the literature on the multidimensional political space and niche political parties, one should expect that there is a substitutive effect; where the stronger a specific master-issue dimension is in party politics, the less salient that issue dimension is in protest politics. This substitutive effect results from the tendency of electoral politics to reduce political conflict to a single-dimension equilibrium, which decreases the importance of other issues and relegates the contest over secondary, niche issues to the realm of policy-seeking strategies, with protest being a common type of this political strategy. In party systems where single-dimension equilibrium does not exist and the master-issue dimension is weaker, the same dynamics result in a more convergent relationship between party and protest politics and a greater similarity between the protest- and party-system agendas. To investigate this theory, the national protest agendas in four countries are examined. The Czech Republic, Hungary, Poland and Slovakia show four combinations of two crucial factors that are not available in the old Western democracies: the content and the strength of the master-issue dimension. The study draws on an original dataset of protest events organised in the four countries between 1993 and 2010, and on qualitative and quantitative data on issue dimensions of party politics obtained from studies on party politics and expert surveys. The results show that in the Czech Republic, where the master-issue dimension has remained strongly economic, protest has been predominantly sociocultural. In Poland between 1993 and 2001 and Hungary between 1993 and 2006, the master-issue dimensions are strongly sociocultural, while protest is predominantly economic. There is no single-dimension equilibrium in party politics in Slovakia or in post-2001 Poland and mainstream parties compete on both economic and sociocultural issues. Consequently, the substitutive dynamics between party and protest politics is weaker and the issue agendas in party and protest arenas are here more alike. <br/

    Understanding the rift, the (still) uneasy bedfellows of History and Organization Studies

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    Although the use of History has become increasingly discussed and more widely applied within Organization Studies (OS), its relevance for OS still remains far from centrally accepted. This article historicizes the relationship between Sociology and History as a means of better understanding the tensions, perceived and real, that exist between History and Organization Studies. In particular we analyse three differences of epistemological standpoint (method, objectivity and usefulness) that are commonly seen as the foundation stones to incompatibility. Perhaps surprisingly for an analysis of apparent disciplinary differences, we find that these distinctions in terms of approach, once closely examined, are rarely clear-cut and historians and OS scholars are frequently closer in intention and method than they are distant. However, despite their large intersection of interests, we argue that important distinctions between the two fields should be acknowledged. Our contribution to the debates over the need for more historical approaches within OS therefore centrally rests on abandoning aspirations for fully integrative models of working together, in favour of cooperative modes that concede the fieldsā€™ differences. This subtle shift of emphasis will, we believe, greatly benefit OS scholars who hope to include historical perspectives in their work
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