Sciences Po Toulouse

The gravity equation in international trade is one of the most robust empirical finding in economics: bilateral trade between two countries is proportional to size, measured by GDP, and inversely proportional to the geographic distance between them. While the role of size is well understood, the role of distance remains a mystery. I propose the first explanation for the gravity equation in international trade, based on the emergence of a stable network of input-output linkages between firms. Over time, a firm acquires more suppliers and customers, which tend to be further away. I show that if, as observed empirically, (i) the distribution of firm sizes is well approximated by Zipf's law and (ii) larger firms export over longer distances on average, then aggregate trade is inversely proportional to distance. Data on firm level, sectoral, and aggregate trade support further predictions of the model.

Abstract The multi-faceted concept of proximity is often used nowadays in many theoretical and empirical analyses. It mainly originates in some French regional scientists' attempt, in the early 1990s, to develop new conceptual and methodological avenues with a view to the study of the industrial and spatial dynamics. The wide diffusion of the resulting research findings is explained by the fact that these scholars realized early on that it was in their interest to collectively structure their works through the setting-up of a research group. The present paper sets out to outline the scientific and institutional trajectories of the French group “Proximity Dynamics”, while underlining the progressive broadening of its scientific and institutional dimensions, as well as the main theoretical research fields these trajectories have permitted to investigate.

International audience

In a recent literature, the structural properties of knowledge networks have been pointed out as a critical factor for cluster structural changes and long-run dynamics. Mixing evolutionary economic geography and network-based approach of clusters, this contribution aims at capturing and discussing the particular influence of hierarchy (degree distribution) and assortativity (degree correlation) in the innovative capabilities of clusters along the industry life cycle. We test our propositions in the field of the mobile phone industry in Europe from 1988 to 2008. We use EPO PATSTAT and OECD REGPAT to capture cluster trends, and R&D relations from European Framework Programs to capture knowledge networks and their evolving structural properties. Our findings provide new insights to understand the organization of clusters over time to perform along the industry life cycle.

The present paper investigates the location patterns and the effects co-working spaces (CWS) generate on the urban context. The focus is on Barcelona, one of the most important creative hubs in Europe in terms of knowledge-based, creative, digital, and sharing economy, and the city hosting the largest number of co-working spaces in Spain. The paper addresses three main questions: (1) Which are the location patterns of co-working spaces in Barcelona? (2) Do CWS agglomerate in the same areas? And, (3) Do CWS coagglomerate with the creative industries (CIs)? To do that, this paper uses open data on Barcelona neighbourhoods’ socioeconomic composition provided by the Statistics Department of the Council of Barcelona and micro-geographic data of private CWS and creative labs in Barcelona. By using Geographical Information Systems (GIS) and Kd functions of agglomeration and coagglomeration, results show that CWS are highly concentrated in central areas of Barcelona where there are greater chances to meet customers and suppliers, the proximity to urban amenities and the fact of being associated to a specific place-image. Moreover, they coagglomerate with CIs firms, especially with symbolic and synthetic knowledge-based CIs. These results are relevant when assessing the actual goal of urban policies in Barcelona.

ABSTRACT We study managerial incentive provision under moral hazard when growth opportunities arrive stochastically and pursuing them requires a change in management. A trade‐off arises between the benefit of always having the “right” manager and the cost of incentive provision. The prospect of growth‐induced turnover limits the firm's ability to rely on deferred pay, resulting in more front‐loaded compensation. The optimal contract may insulate managers from the risk of growth‐induced dismissal after periods of good performance. The evidence for the United States broadly supports the model's predictions: Firms with better growth prospects experience higher CEO turnover and use more front‐loaded compensation.

Past observations and satellite sea surface temperature imagery indicate the presence of mesoscale anticyclonic eddies drifting along the Catalan coast. In September 2001 one of these anticyclonic eddies was surveyed over the shelf break during an oceanographic cruise which permitted the 3‐D description of its structure. In this work we investigate the origin and dynamics of such “Catalan eddies” using a numerical circulation model of the northwest Mediterranean at 3 km resolution driven by high‐resolution atmospheric analyses and compare model eddies with the observations in the Catalan Sea. We identify two zones of eddy formation in the Gulf of Lions, in front of the city of Marseille and at the southeast of coast of Roussillon, from which anticyclonic eddies are observed to drift toward the Catalan Sea. The hydrology and dynamics of the structures observed in the simulations are characterized. Sensitivity experiments and energy analysis are performed which allow us to identify the mechanisms associated with their generation. Properties of the eddy observed during the 2001 cruise at the Catalan shelf break are found to compare well with model eddies generated at the southeast of the Roussillon coast. The model relates the origin of these eddies to the separation of the coastal current downstream from Creus Cape: flow separation is linked to intense downwelling taking place in front of the Roussillon coast when strong northwesterly winds events occur.

Since the adoption of the Sustainable Development Goals by the United Nations, sustainability has been a key priority for European governments. While previous studies have investigated the associations between indicators of sustainable development, few have directly considered a multidimensional approach to assess and compare the performance of regions in terms of sustainable development. As such, a comprehensive assessment of regional sustainable performance is thus still needed. In this paper, the concept of sustainability relies on the construction of six composite indices (environment and natural resources, energy transition, sustainable mobility, economic dynamism, social cohesion and solidarity, and governance and citizenship) with the aim to provide an evaluation framework for empirically comparing the performance of the 96 metropolitan French Departments. Each dimension is explored by spatial autocorrelation analysis and Hierarchical Ascending Classification (HAC) to classify French Departments providing five different regional profiles of sustainable development. The findings make it possible to identify the strengths and weaknesses of the departments in the implementation of sustainable development. This approach provides the bases for a systematic monitoring of sustainable development policies at the regional scale.

L'espace public : une notion essentielle mais souvent galvaudée. Ce livre s'efforce de dépasser la vision jacobine d'un espace public unifié et hiérarchique pour penser cette structure en termes d'éclatement, d'hétérogénéité, de mosaïque. Il a pour ambition de contribuer à des questions importantes de sociologie politique : dans quelles conditions les agents « ordinaires » peuvent-ils accéder à l'espace public ? Pour quelles conditions peut-on encore « parler l'universel » dans des arènes médiatiques envahies par l'émotion et l'irrationnel ?

This article explores the differences in radical right parties' voting behaviour on economic matters at the European Parliament. As the literature highlights the heterogeneity of these parties in relation to their economic programmes, we test whether divergences survive the elections and translate into dissimilar voting patterns. Using voting records from the seventh term of the European Parliament, we show that radical right parties do not act as a consolidated party family. We then analyse the differences between radical right parties by the means of different statistical methods (NOMINATE, Ward's clustering criterion, and additive trees) and find that these are described along two dimensions: the degree of opposition to the European Union and the classical left–right economic cleavage. We provide a classification of these parties compromising four groups: pro-welfare conditional, pro-market conditional, and rejecting. Our results indicate that radical right parties do not act as a party family at the European Parliament. This remains true regardless of the salience of the policy issues in their agendas. The article also derives streams for future research on the heterogeneity of radical right parties.

A new generation of optimized contrast agents is emerging, based on metallic nanoparticles (NPs) and semiconductor nanocrystals for, respectively, magnetic resonance imaging (MRI) and near-infrared (NIR) fluorescent imaging techniques. Compared with established contrast agents, such as iron oxide NPs or organic dyes, these NPs benefit from several advantages: their magnetic and optical properties can be tuned through size, shape and composition engineering, their efficiency can exceed by several orders of magnitude that of contrast agents clinically used, their surface can be modified to incorporate specific targeting agents and antifolding polymers to increase blood circulation time and tumour recognition, and they can possibly be integrated in complex architecture to yield multi-modal imaging agents. In this review, we will report the materials of choice based on the understanding of the basic physics of NIR and MRI techniques and their corresponding syntheses as NPs. Surface engineering, water transfer and specific targeting will be highlighted prior to their first use for in vivo real-time imaging. Highly efficient NPs that are safer and target specific are likely to enter clinical application in a near future.

This paper presents a detailed analysis of how liquid money market instruments -- sterling bills of exchange -- were produced during the first globalisation. We rely on a unique data set that reports systematic information on all 23,493 bills re-discounted by the Bank of England in the year 1906. Using descriptive statistics and network analysis, we reconstruct the complete network of linkages between agents involved in the origination and distribution of these bills. Our analysis reveals the truly global dimension of the London bill market before the First World War and underscores the crucial role played by London intermediaries (acceptors and discounters) in overcoming information asymmetries between borrowers and lenders on this market. The complex industrial organisation of the London money market ensured that risky private debts could be transformed into extremely liquid and safe monetary instruments traded throughout the global financial system.

This paper presents a model of international portfolios with real exchange rate and non financial risks that accounts for observed levels of equity home bias. A key feature is that investors can trade equities as well as domestic and foreign real bonds. Bonds matter: in equilibrium, investors structure their bond portfolio to hedge real exchange rate risk since relative bond returns are strongly correlated with real exchange rate movements. Equity home bias does not arise from the co-movements between relative stock returns and real exchange rates, but from the hedging properties of stock returns against other sources of risk, conditionally on bond returns. We estimate the optimal equity and bond portfolios implied by the model for G-7 countries and find strong empirical support for the theory. We are able to account for a significant share of the equity home bias and obtain a currency exposure of bond portfolios comparable to the data.

International audience

Le territoire n’est pas au départ un concept économique, l’économie spatiale néo-classique étant largement a-territoriale. L’économie s’y est intéressée depuis environ deux décennies. Cet article s’interroge sur la place du territoire dans l’analyse économique, et sur son lien avec les concepts de patrimoine et d’identité. Développé par des courants hétérodoxes et institutionnalistes, il est parfois remis en cause par ces mêmes courants. Nous avançons que seul le passage par la qualification des biens et des actifs dans les processus de production et de consommation permet de lui donner un statut endogène, comme élément de définition d’une caractéristique de qualité. En effet le processus de qualification implique des références au patrimoine et à l’identité des acteurs, concepts également pris en compte par des économistes. La construction d’une identité territoriale est indissociable de l’action de groupes localisés qui construisent la patrimonialisation de certaines ressources exclusives. Ceci amène à relativiser largement la vision d’un patrimoine et d’une identité donnés a priori.

Crespo J. and Vicente J. Proximity and distance in knowledge relationships: from micro to structural considerations based on territorial knowledge dynamics (TKDs), Regional Studies. Among the key parameters identified in territorial knowledge dynamics (TKDs), this paper focuses on the balance and trade-off between proximity and distant relations, especially as far as knowledge relationships are concerned. This entry is investigated through an original process consisting in combining micro-motives for knowledge relationships and structural properties of resulting knowledge networks, always paying attention to the balance between proximity and distance. From the information available in EURODITE case studies and the presentation of the methodology, the micro-foundations of proximity and distance in knowledge relationships are explored according to the knowledge trade-off and the complex knowledge value chain that typify the modern knowledge process. Based on these micro-considerations, a structural analysis of TKDs is inferred that provides significant patterns of their structuring. From these patterns policy implications are extracted which show that collaborative incentives on some particular missing links fit better with effective policies than the common view of ‘connecting people’ policies.

Despite global efforts to harmonize international trade statistics, our understanding of digital trade and its implications remains limited. Here, we introduce a method to estimate bilateral exports and imports for dozens of sectors starting from the corporate revenue data of large digital firms. This method allows us to provide estimates for digitally ordered and delivered trade involving digital goods (e.g. video games), productized services (e.g. digital advertising), and digital intermediation fees (e.g. hotel rental), which together we call digital products. We use these estimates to study five key aspects of digital trade. We find that, compared to trade in physical goods, digital product exports are more spatially concentrated, have been growing faster, and can offset trade balance estimates, like the United States trade deficit on physical goods. We also find that countries that have decoupled economic growth from greenhouse gas emissions tend to have larger digital exports and that digital exports contribute positively to the complexity of economies. This method, dataset, and findings provide a new lens to understand the impact of international trade in digital products.

The platformization of the public sphere refers to the increasing dominance of digital platforms in shaping public discourse, access to information, and the production and dissemination of political content. The public sphere, where citizens inform themselves and engage in political debates, is being transformed by global private corporations like Alphabet and Meta. Their platforms exercise control over cultural producers, political actors, and the distribution of information and communication resources. At the same time, in a context of multiple crises of liberal democracies under capitalism, they offer personalization of content, services, and experiences contributing to the fragmentation of the political landscape. Thus, the platformized public sphere bears a fundamental contradiction in that it emerges through the dialectics between concentration and fragmentation. This has significant implications for freedom of expression, journalism, and the way public discourse is constructed and disseminated. The aim of this issue is to shed light on these fundamental stakes.

Cet article fait un bilan de l’approche économique de la notion de système agroalimentaire localisé (SYAL) apparu depuis environ une dizaine d’années. Il cherche notamment à la positionner par rapport à la notion de Système Productif Local : s’agit-il d’une simple déclinaison sectorielle du concept de SPL ou identifie-t-elle des dimensions spécifiques de l’ancrage territorial. La thèse défendue est que, si les deux notions entretiennent une parenté évidente, l’analyse des SYAL fait apparaître une relation spécifique au territoire, à travers les processus de qualification des produits agroalimentaires notamment et la relation au développement durable.

À la suite d’une abondante littérature sur le rôle important du développement des clusters pour l’innovation et la croissance dans les économies fondées sur la connaissance, les politiques de cluster ont été récemment et de façon croissante remises en cause par les évidences empiriques. Le but de l’article est de montrer qu’en dépit de ce scepticisme croissant, de nouvelles opportunités pour les politiques de soutien aux clusters et leur management collectif existent. Ces opportunités requièrent de passer de la logique du « tout réseau » qui caractérise les « cluster policy guidelines » à des formes plus chirurgicales et ciblées d’incitation à la collaboration dans la R&D, ainsi qu’à des dispositifs renouvelés de coordination, favorisant un ensemble de propriétés structurelles des réseaux le long des phases du cycle de vie des clusters.